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1
Aziz, Maheran Abd. "In vitro genetic manipulation of the genus Lotus." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277932.
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Raelson, John Verner. "An isoenzyme study in the Genus lotus (Fabaceae) /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75682.
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An isoenzyme survey of several taxa within the genus Lotus was undertaken to provide markers for genetic research and to test hypotheses concerning the phylogenetic origin of Lotus corniculatus L. A preliminary study identified seven enzyme systems PGI, TPI, PGM, MDH, IDH, 6-PGDH and ME, that produced consistent clear phenotypes in L. uliginosus Schkuhr. Variation in phenotype with tissue type and stage of development suggested the presence of several isozyme zones in the phenotypes. Enzyme phenotype was constant for shoot tissue of plants older than six weeks. A second study examined recombination and segregation of isoenzyme phenotypes in interspecific hybrids, allo- and autopolyploids, and in L. corniculatus. Duplication and quadruplication of pgi2 loci in hybrids, amphidiploids, and in L. corniculatus was used as evidence that the latter is a segmental allotetraploid. A third study surveyed the occurrence of various isoenzyme alleles in L. alpinus Schleich., L. japonicus (Regel) Larsen, L. tenuis Waldst. & Kit., L. uliginosus and L. corniculatus. Lotus uliginosus had unique distinct alleles for several enzymes that did not occur in the other species. This evidence argues against the involvement of L. uliginosus in the origin of L. corniculatus.
3
Emery, Keith Martin. "Population dynamics of Birdsfoot trefoil in relation to disease and microclimate /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9842525.
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4
Ollerton, J. "Ecology of flowering and fruiting in Lotus corniculatus L." Thesis, Oxford Brookes University, 1993. http://radar.brookes.ac.uk/radar/items/0a08eb77-6970-5ea7-9fe7-372ef1e96b25/1.
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Lotus corniculatus L. (Legtuninosae), is a perennial herb common throughout Britain. Its main pollinators are bumblebees (Bombus spp., Apidae: Hymenoptera). This is a study of the ecological factors which are important to flowering and fruiting in the species, and some of their evolutionary implications. The work was carried out at Wytham Estate, Oxfordshire, U.K., mainly in an ex-arable field (Upper Seeds) and a more established grassland (Lower Seeds Reserve). The literature on self-incompatibility in L. corniculatus is reviewed; there are conflicting reports, but wild material is fundamentally self-incompatible. Plants in Upper Seeds are larger than in Lower Seeds Reserve. Comparative data on soil nutrients in the two sites suggests that the cause is the persistence of phosphorus from inorganic fertiliser. There is a positive, linear relationship between plant size, flower production and fruit production. The species regulates investment in flowers mainly at the level of the whole inflorescence, rather than altering number of flowers per inflorescence. Within individuals, there are no consistent trade-offs between number of fruit per infructescence, numbers of seeds per fruit and seed weight. Weather patterns only partially explain the flowering phenology of L. corniculatus. Timing of first flowering and peak flowering are correlated but are variable between individuals, and between years for the same individuals. They are not correlated with flowering synchrony. An individual's flowering pattern does not consistently affect fruit-set; the overriding determinant of fruit production is plant size. Selection is therefore unlikely to be acting on flowering time in this species. The production of large numbers of self-incompatible flowers does not seem to reduce fruit-set; pollinators do not visit enough flowers per foraging trip (perhaps because nectar production is low) for geitonogamy to become a problem. Seed predation by larvae of a chalcid wasp, a weevil and a moth differs between individual plants, but not consistently so between years. Seed predation is not consistently correlated with plant size, mean flowers per inflorescence, number of seeds per fruit or seed size. There is no evidence for selection acting on these traits through seed predation. Partially predated seeds are often viable, which may have implications for seedling demography. Seed predation and flowering phenology are not defmitively linked, strengthening the argument that flowering time is not adaptive in this species.
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Nualsri, Charassri. "Inheritance of rhizome expression in birdsfoot trefoil (Lotus corniculatus l.) /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9717176.
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Gibbs, Margaret Joan. "Genetic engineering of the forage legume Lotus corniculatus using Agrobacterium : mediated transformation systems." Thesis, Durham University, 1991. http://etheses.dur.ac.uk/6040/.
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Gene transfer vectors based on the Agrobacterium tumefaciens Ti plasmid were used to develop a successful disarmed Agrobacterium tumefaciens-mediated transformation method for Lotus comiculatus. A binary vector construct, pJIT73, was used during the development of the Agrobacterium tumefaciens transformation system due to its selectable (Aph IV, nos- neo) and scorable markers. The effects of the antibiotics geneticin (G-418) and hygromycin B were studied. Use of kill curves and selection delay experiments allowed potentially suitable selection pressure parameters to be proposed. Using such selection during transformation experiments led to further optimisation of this stage of transformation. The influence of plant hormones on the regeneration of Lotus comiculatus explants was investigated and a modification of an established protocol using leaf explants was introduced as an attempt to reduce the overall time of regeneration. Various explants were used but leaf pieces were chosen as the most suitable explant on which to focus research. So, through alteration of various stages, including length of cocultivation and subsequent decontamination within the transformation process, a successful method was developed. Experiments indicated the optimum Agrobacterium tumefaciens strain to be used with Lotus comiculatus was the disarmed Ach5 type, LBA4404(pAL4404). Transgenic Lotus comiculatus plants were produced which expressed the scorable marker β-Glucuronidase gene (GUS) and the selectable marker for hygromycin B resistance, AphIV. Gene transfer was confirmed by Southern blotting. The new Agrobacterium tumefaciens-mediated vector system was used to introduce the cowpea trypsin inhibitor gene (CpTi) into Lotus comiculatus. However, although there was evidence for transformed callus development, no shoots were induced. By the use of previously established Agrobacterium rhizogenes-mediated system, an attempt was made to introduce the pea lectin gene (psl) into Lotus corniculatus. Hairy root regenerants were produced but genetic transfer was unconfirmed and attempted investigation of the plant - Rhizobium symbiosis involving Lotus corniculatus was not fulfilled.
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Rodpothong, Patsarin, and n/a. "Host-specific Nod factor requirements for nodulation of Lotus species by Mesorhizobium loti." University of Otago. Department of Microbiology & Immunology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080910.113419.
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Mesorhizobium loti possesses a symbiosis island (ICEMlSym[R7A]) that confers upon the bacterium the ability to form a symbiotic association with legumes of the genus Lotus. Nodulation (nod, nol and noe) genes located on the ICEMlSym[R7A] encode enzymes that are responsible for the production of a species-specific signaling molecule, named Nod factor. Perception of Nod factors by plant receptors triggers several plant responses and facilitates bacterial invasion, leading to the formation of root nodules. The studies in this thesis aimed to examine the impact of various structural components of the M. loti Nod factor on host specificity and recognition within Lotus species. The minimal gene requirement for eliciting nodule development on Lotus plants was also determined.
The M. loti strain R7A Nod factor has a backbone of five N-acetyl-D-glucosamine (GlcNAc) residues. The non-reducing terminal GlcNAc residue carries an acyl chain of either a vaccenic acid (C[18:1]) or palmitic acid (C[16:0]), a carbamoyl group and a methyl group, while an acetylfucose is present at the reducing terminus. Analysis of loss-of-function [Delta]nodZ and [Delta]nolL mutants showed that the acetylfucose at the reducing terminus was required for efficient nodulation of Lotus species, especially during the initiation of infection threads and for induction of symbiotic gene, NIN. Upon inoculation with R7A[Delta]nodZ, nodulation of Lotus corniculatus and L. filicaulis was significantly delayed and reduced, while only a delay in the onset of nodulation was observed with L. japonicus. Interestingly, nodulation of L. burttii induced by R7A[Delta]nodZ was as efficient as that induced by R7A. Hence, the absolute requirement for the acetylfucose during nodulation was host-dependent.
In planta complementation and domain swap experiments using transgenic L. japonicus nfr1 and nfr5 mutants were employed to investigate the role of the reducing terminal acetylfucose in the perception of Nod factor. Nodulation of complemented L. japonicus nfr1 and nfr5 mutants inoculated with R7A[Delta]nodZ was poor, whereas similar plants inoculated with R7A nodulated well. This suggests that the in planta complementation was inefficient and as a result accentuated the effect of the acetylfucose on the Nod factor recognition. The responses of recombinant inbred lines (RILs) derived from a cross between L. filicaulis and L. japonicus to inoculation with strain R7A[Delta]nodZ suggested that at least two genetic loci on chromosome 4, in addition to the Nfr1 and Nfr5 genes, contribute to Nod factor perception and in particular the host-specific recognition of the acetylfucose, This suggests the involvement of multiple receptors or a receptor with multiple components in the perception of Nod factors.
A gain-of-function study demonstrated that the presence of nodulation genes alone in nonsymbiotic mesorhizobia was sufficient to induce nodulation and bacteroid formation on Lotus plants, indicating that no other ICEMlSym[R7A] genes were required for infection thread formation or bacterial release. Nodulation assays of four Lotus species indicated host-specific requirements for nodulation genes. The presence of the nodA, nodC, nodD1, nodD2, nodZ, noeL and nolK genes was sufficient to permit nodulation of L. burttii, but was insufficient to induce nodulation of L. japonicus, L. corniculatus and L. filicaulis. The importance of the carbamoyl and methyl groups, and the influence of Nod factor concentration during nodulation were also implicated in this study. A model for the Nod factor perception in Lotus was proposed.
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Raikar, S. V. "Protoplast fusion of Lolium perenne and Lotus corniculatus for gene introgression." Diss., Lincoln University, 2007. http://hdl.handle.net/10182/301.
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Lolium perenne is one of the most important forage crops globally and in New Zealand. Lotus corniculatus is a dicotyledonous forage that contains valuable traits such as high levels of condensed tannins, increased digestibility, and high nitrogen fixing abilities. However, conventional breeding between these two forage crops is impossible due to their markedly different taxonomic origin. Protoplast fusion (somatic hybridisation) provides an opportunity for gene introgression between these two species. This thesis describes the somatic hybridisation, the regeneration and the molecular analysis of the putative somatic hybrid plants obtained between L. perenne and L. corniculatus. Callus and cell suspensions of different cultivars of L. perenne were established from immature embryos and plants were regenerated from the callus. Of the 10 cultivars screened, cultivars Bronsyn and Canon had the highest percentage of callus induction at 36% each on 5 mg/L 2,4-D. Removal of the palea and lemma which form the seed coat was found to increase callus induction ability of the embryos. Plant regeneration from the callus was achieved when the callus was plated on LS medium supplemented with plant growth regulators at different concentrations. Variable responses to shoot regeneration was observed between the different cultivars with the cv Kingston having the lowest frequency of shoot formation (12%). Different factors affecting the protoplast isolation of L. perenne were investigated. The highest protoplast yield of 10×10⁶ g⁻¹FW was obtained when cell suspensions were used as the tissue source, with enzyme combination 'A' (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. Development of microcolonies was only achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. All the shoots regenerated from the protoplast-derived calli were albino shoots. The highest protoplast yield (7×10⁶ g⁻¹FW) of L. corniculatus was achieved from cotyledons also with enzyme combination 'A' (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. The highest plating efficiency for L. corniculatus of 1.57 % was achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. The highest frequency of shoot regeneration (46%) was achieved when calli were plated on LS medium with NAA (0.1 mg/L) and BA (0.1 mg/L). Protoplast fusion between L. perenne and L. corniculatus was performed using the asymmetric somatic hybridisation technique using PEG as the fusogen. L. perenne protoplasts were treated with 0.1 mM IOA for 15 min and L. corniculatus protoplasts were treated with UV at 0.15 J/cm² for 10 min. Various parameters affecting the fusion percentage were investigated. Successful fusions were obtained when the fusions were conducted on a plastic surface with 35% PEG (3350 MW) for 25 min duration, followed by 100 mM calcium chloride treatment for 25 min. A total of 14 putative fusion colonies were recovered. Shoots were regenerated from 8 fusion colonies. Unexpectedly, the regenerated putative hybrid plants resembled L. corniculatus plants. The flow cytometric profile of the putative somatic hybrids resembled that of L. corniculatus. Molecular analysis using SD-AFLP, SCARs and Lolium specific chloroplast microsatellite markers suggest that the putative somatic hybrids could be L. corniculatus escapes from the asymmetric protoplast fusion process. This thesis details a novel Whole Genome Amplification technique for plants using Strand Displacement Amplification technique.
9
Tatsukami, Yohei. "Studies on symbiosis-spesific phenotype of Mesorhizobium loti and its function to host plant." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225663.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第20438号
農博第2223号
新制||農||1049(附属図書館)
学位論文||H29||N5059(農学部図書室)
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 植田 充美, 教授 矢﨑 一史, 教授 森 直樹
学位規則第4条第1項該当
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Stettler, Jason M. "Utah Lotus: North American Legume for Possible Use in Rangeland Revegetation in the Southern Great Basin of the Western United States." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4894.
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Utah lotus (Lotus utahensis Ottley) is a North American legume related to the Eurasian birdsfoot trefoil (L. corniculatus L.), which is an economically valuable forage legume for pastures. Our objectives were to describe the genetic variation within Utah lotus seed collections by measuring adaptive phenotypic traits at three common garden sites in northern Utah, and to determine the genetic structure of populations and the extent of local adaptation through AFLP (amplified fragment length polymorphisms) analysis. We evaluated 14 Utah lotus seed collections from Nevada and Utah, and five seed collections of scrub lotus (L. wrightii (A. Gray) Greene) from Arizona. Significant variation was observed among collections for all phenotypic traits measured. Spring emergence date, flowering date, survival, dry-matter yield, and canopy width discriminated these two species with 100% accuracy. Population structure estimates from 552 AFLP markers of Utah lotus, scrub lotus, and the birdsfoot trefoil check resulted in five genetically differentiated groups. The three primary groups were the three species; within the Utah lotus collections three sub-groups were identified, which corresponded to geographic locations of the collection sites. Two collections of Utah lotus (LU-5 and LU-20) were among the top-tier collections for important phenotypic traits, including dry-matter yield, pod production, number of stems, canopy height, and survival. No significant Pearson’s correlations or canonical correlations were found among the phenotypic traits and environmental characteristics at the collection sites. Significant correlations were detected between genetic and geographic, and phenotypic and geographic distance matrices (r = 0.888, P = 0.001 and r = 0.235, P = 0.044, respectively). No other significant distance matrix correlations were found. Despite the significant isolation by distance correlation, both the genetic and phenotypic evaluations provide little evidence to support local adaptation. Based on these results, one pooled germplasm source of Utah lotus could be developed for use in rangeland restoration and revegetation of the southern Great Basin. Collections LU-5 and LU-20 would be good candidate collections that would represent minimal risk of maladaptation and out-breeding depression with natural populations.
11
Engerberg, Malin. "Development of database support for production of doubled haploids." Thesis, University of Skövde, Department of Computer Science, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-711.
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In this project relational and Lotus Notes database technology are evaluated with regard to their suitability in providing computer-based support in plant breeding in general and specifically in the production of doubled haploids. The two developed databases are compared based on a set of requirements produced together with the DH-group which is the main users of the databases. The results indicate that both Lotus Notes and the relational databases are able to fulfil all needs documented in this project, although both systems have their limitations. An often expressed opinion is that it is difficult to combine biology and databases. The experience gained in this project however suggests that it does not need to be the case in instances where data is not as complicated as often discussed. Observations made during this project indicate that data warehousing with integrated data mining and OLAP tools are surprisingly similar to how the DH-group at Svalöf Weibull works and could be a suitable solution for the production of doubled haploids.
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Binder, Andreas [Verfasser], and Martin [Akademischer Betreuer] Parniske. "Characterization of the Lotus Japonicus nuclear pore NUP107-160 subcomplex in plant-microbe symbiosis / Andreas Binder. Betreuer: Martin Parniske." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1100396020/34.
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Hunt, Sara. "Stem Development, Seeding Rate, and Establishment of Birdsfoot Trefoil (Lotus corniculatus) for Organic, Grazing-Based Dairies." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3332.
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Three studies applicable to organic management and cultivation of birdsfoot trefoil (BFT, Lotus corniculatus L.) are presented here. The first is a histological analysis of lignification in BFT stems that supports recommendations to harvest BFT at approximately 6 weeks of regrowth, or early bloom. Lignification decreases digestibility and is correlated with high shear force required to break BFT stems. The sixth internodes from the base of 10 BFT and two alfalfa plants were sampled during 15 weeks of midsummer regrowth. The lignified xylary ring reached its maximum radial width by 7.5 weeks of regrowth, and full bloom was reached by 6.5 weeks of regrowth.
The second study evaluated establishment of BFT, which competes poorly with weeds and produces low yields during establishment. At an organic, irrigated site in northern Utah the effects of autumn vs. spring seeding, seeding rates of 3, 7 20, and 34 kg pure live seed (PLS) ha-1 and use of a companion crop on 3 years of annual yields and foliar cover of mature stands were determined. First year yields increased linearly with seeding rate (P≤0.05). Use of a companion crop reduced first year yields, and did not reduce weed cover. Autumn seeding of BFT alone, following harvest of a summer crop, is recommended for irrigated production.
The final study evaluated BFT establishment on five organic dairy farms in souther Idaho and northern Utah. Participating producers broadcast seeded 4-ha BFT pastures in the fall at a rate of 25 kg PLS ha-1. All farms achieved high BFT density, but only two farms had higher BFT than weed density. These two farms also had high BFT cover the spring following autumn seeding, and their pastures produced 6000 to 7600 kg of dry matter ha-1 by 20 June 2012 and supported grazing for the remainder of the summer. Establishment was enhanced by crop rotation and sprinkler irrigation.
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Raikar, Sanjeev Vencu. "Protoplast fusion of Lolium perenne and Lotus corniculatus for gene introgression." Phd thesis, Lincoln University. Bio-Protection and Ecology Division, 2007. http://theses.lincoln.ac.nz/public/adt-NZLIU20080214.105406/.
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Protoplast fusion of Lolium perenne and Lotus corniculatus for gene introgression
by Sanjeev V. Raikar
Lolium perenne is one of the most important forage crops globally and in New Zealand. Lotus corniculatus is a dicotyledonous forage that contains valuable traits such as high levels of condensed tannins, increased digestibility, and high nitrogen fixing abilities. However, conventional breeding between these two forage crops is impossible due to their markedly different taxonomic origin. Protoplast fusion (somatic hybridisation) provides an opportunity for gene introgression between these two species. This thesis describes the somatic hybridisation, the regeneration and the molecular analysis of the putative somatic hybrid plants obtained between L. perenne and L. corniculatus.
Callus and cell suspensions of different cultivars of L. perenne were established from immature embryos and plants were regenerated from the callus. Of the 10 cultivars screened, cultivars Bronsyn and Canon had the highest percentage of callus induction at 36% each on 5 mg/L 2,4-D. Removal of the palea and lemma which form the seed coat was found to increase callus induction ability of the embryos. Plant regeneration from the callus was achieved when the callus was plated on LS medium supplemented with plant growth regulators at different concentrations. Variable responses to shoot regeneration was observed between the different cultivars with the cv Kingston having the lowest frequency of shoot formation (12%).
Different factors affecting the protoplast isolation of L. perenne were investigated. The highest protoplast yield of 10×106 g-1FW was obtained when cell suspensions were used as the tissue source, with enzyme combination A (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. Development of microcolonies was only achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. All the shoots regenerated from the protoplast-derived calli were albino shoots.
The highest protoplast yield (7×106 g-1FW) of L. corniculatus was achieved from cotyledons also with enzyme combination A (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. The highest plating efficiency for L. corniculatus of 1.57 % was achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. The highest frequency of shoot regeneration (46%) was achieved when calli were plated on LS medium with NAA (0.1 mg/L) and BA (0.1 mg/L).
Protoplast fusion between L. perenne and L. corniculatus was performed using the asymmetric somatic hybridisation technique using PEG as the fusogen. L. perenne protoplasts were treated with 0.1 mM IOA for 15 min and L. corniculatus protoplasts were treated with UV at 0.15 J/cm2 for 10 min. Various parameters affecting the fusion percentage were investigated. Successful fusions were obtained when the fusions were conducted on a plastic surface with 35% PEG (3350 MW) for 25 min duration, followed by 100 mM calcium chloride treatment for 25 min. A total of 14 putative fusion colonies were recovered. Shoots were regenerated from 8 fusion colonies. Unexpectedly, the regenerated putative hybrid plants resembled L. corniculatus plants.
The flow cytometric profile of the putative somatic hybrids resembled that of L. corniculatus. Molecular analysis using SD-AFLP, SCARs and Lolium specific chloroplast microsatellite markers suggest that the putative somatic hybrids could be L. corniculatus escapes from the asymmetric protoplast fusion process. This thesis details a novel Whole Genome Amplification technique for plants using Strand Displacement Amplification technique.
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Wewer, Vera [Verfasser]. "The Role of Glycolipids at the Interface of Plant-Microbe Interactions during Nodulation and Mycorrhiza Formation in Lotus japonicus / Vera Wewer." Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/1049984919/34.
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Tian, Daike Tilt Kenneth Michael. "Container production and post-harvest handling of lotus (Nelumbo) and micropropagation of herbaceous peony (Paeonia)." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Horticulture/Dissertation/Tian_Daike_59.pdf.
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Campos, Lázara Pereira. "Genome relationships among Lotus species based on random amplified polymorphic DNA (RAPD)." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56888.
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The usefulness of RAPDs (Random Amplified Polymorphic DNA) to distinguish among different taxa of Lotus was evaluated. The following species were included: L. corniculatus, L. tenuis, L. alpinus, L. japonicus, and L. uliginosus. Several accessions for each species were studied. Following DNA extraction, amplification reactions were performed in a Hybaid DNA Thermal Cycler, and the product visualized according to a standard procedure. Twenty primers were used for each species/accession. Clear bands and several polymorphisms were obtained for all primers. A phenogram was drawn based on the genetic distance among the species. L. alpinus appears as the most distant species from L. corniculatus, followed by L. uliginosus, L. tenuis, and L. japonicus. With the exception of L. alpinus, these findings are in agreement with previous experimental studies in the L. corniculatus group. The use of a greater number of primers and increased number of species may provide a greater resolution of the systematics of these taxa.
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Pofelis, Shoshana. "The development of sulfonylurea herbicide resistant birdsfoot trefoil (Lotus corniculatus) plants from in vitro selection /." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60086.
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Birdsfoot Trefoil (Lotus corniculatus L. cv. Leo), is a perennial forage legume that has difficulty in establishing stands due to slow seedling growth, weed competition and herbicide sensitivity. The development of herbicide resistant cultivars would be of economic importance. Resistant lines were isolated after sequential selection at the callus, shoot and whole plant levels to the sulfonylurea (SU) herbicides Harmony (DPX-M6316, code name for methyl 3- ( ( ((4-methoxy-6-methyl-1,3,5,triazine-2-yl)amino) carbonyl) amino) sulfonyl-2-thiophenecarboxylate), or Classic (DPX-F6025, code name for 2(( (4-chloro-6-methoxypyrimidine-yl)amino carbonyl) aminosulfonyl)benzoic acid ethyl ester. In field and growth chamber tests the Harmony regenerant lines displayed an increased tolerance as compared to control plants from tissue culture, and from seed. Results of the evaluation of callus cultures of regenerated mutant lines signify stability of the resistance. Outcrossed seeds collected from field trials, and tested in vitro for herbicide resistance, indicate that the trait is heritable and that resistance may be due to reduced sensitivity of acetolactate synthase to SU inhibition. It is concluded that herbicide resistant birdsfoot trefoil cultivars can be isolated using in vitro selection.
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Stewart, Jennifer Margaret. "The lotus and the waterlily : plants of cultural and social significance." Thesis, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416771.
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Santos, Armando Martins dos. "Melhoramento genético de Lotus corniculatus visando tolerância à toxidez por alumínio." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/25980.
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Solos ácidos com toxidez por Al são comuns, sendo geralmente destinados à pecuária. A utilização de leguminosas forrageiras adaptadas a esta situação minimizaria o uso de correção de acidez e ainda possibilitaria um aporte de N ao sistema via fixação biológica. A caracterização e a identificação de mecanismos de tolerância ao Al tóxico são os passos iniciais em um programa de seleção e melhoramento visando maior adaptação a esta condição de estresse. Este trabalho objetivou: (i) caracterizar genótipos de cornichão (L. corniculatus), espécies diplóides, inclusive da espécie modelo L. japonicus e linhas endogâmicas recombinantes (LER) de Lotus, quanto à tolerância ao Al tóxico; (ii) identificar o acúmulo de Al e exsudação radicular de ácidos orgânicos nas espécies cultivadas; e (iii) selecionar genótipos com respostas contrastantes ao Al tóxico, comparando-os através de caracteristicas agronômicas e moleculares. Os resultados da caracterização mostraram que as espécies modelo diplóides MG-20 e GIFU, a população UFRGS, e as cvs. San Gabriel e São Gabriel foram as mais produtivas de maneira geral. A população UFRGS apresentou ainda uma grande superioridade em situações de moderada acidez do solo (22,2% de Al), demonstrando um potencial de utilização em regiões onde se realize correção parcial do solo. Das 180 LERs testadas, 24 foram superiores e 39 foram inferiores a espécie modelo GIFU. Com relação à exsudação radicular de ácidos orgânicos, na ausência de Al observaram-se baixos níveis de exudação para todos os genótipos. Já na presença do Al, os resultados mostraram que o genótipo UFRGS, selecionado para tolerância ao Al (UF-T2), apresentou aumento significativo (pelo menos 50% superior) da exudação de ácido oxálico em relação aos demais genótipos, assim como a população UFRGS mostrou-se superior à cv. Draco em todas as avaliações. O resultado de dois ciclos de seleção massal visando tolerância ao Al mostrou incrementos na produção de matéria seca em todas as concentrações de Al testadas, enquanto que a seleção para sensibilidade ao Al pareceu estar relacionada com o baixo vigor das plantas, uma vez que na ausência de Al estes genótipos apresentaram menor acúmulo de matéria seca em relação às populações originais. A grande diversidade observada nos genótipos avaliados pode indicar que mecanismos de tolerância ao Al possam atuar em diferentes intensidades. A exudação de ácido oxálico parece ser um mecanismo que permite a manutenção do crescimento do cornichão em condições de Al tóxico, sendo que a seleção de um genótipo mais tolerante ao Al proporcionou aumentos significativos neste mecanismo de defesa.Acid soils with aluminum (Al) toxicity are common, being generally destined for cattle livestock. The utilization of forage legumes adapted to this situation would minimize the use of agricultural liming materials and still allow a nitrogen input to the system via biological fixation. The characterization and identification of tolerance mechanisms to toxic Al are the initial steps in a selection and breeding program aiming a greater adaptation to this stress condition. This work was aimed to: (i) characterize cultivated populations of birdsfoot trefoil (tetraploid), model species (diploid) and recombinant inbred lines (RIL) of Lotus, regarding toxic Al tolerance; (ii) identify the accumulation of Al and root exudation of organic acids in the cultivated species; and (iii) select genotypes with contrasting responses to the toxic Al, comparing their morphological and molecular characteristics. The results of the characterization showed that the diploid genotypes, MG-20 and GIFU, and the cultivated UFRGS genotypes, San Gabriel and São Gabriel were the most productive in a general matter. The UFRGS genotype also presented a great superiority in situations of moderate soil acidity (22,2% of Al), demonstrating a utilization potential in regions where partial soil amelioration is done. Of the180 RILs tested, 24 were superior and 39 were inferior to the GIFU genotype. Regarding root exudation of organic acids, in the absence of aluminum, low levels of exudation were observed for all genotypes. However, in the presence of aluminum, the results showed that the UFRGS genotype selected for Al tolerance presented a significant increase (at least 50% higher) of oxalic acid exudation compared to the other genotypes, and the UFRGS genotype proved superior to the Draco genotype in all evaluations. The result of two mass selection cycles aiming Al tolerance showed increments in dry matter production in all of the toxic aluminum concentrations tested, while the selection for Al sensibility seemed to be related to the plants’ low vigor, since in the absence of Al these genotypes presented a lower accumulation of dry matter compared to the original populations. The great diversity observed in the evaluated genotypes may indicate that the Al tolerance mechanisms may act in different intensities. The exudation of oxalic acid is apparently a mechanism that permits the maintenance of the birdsfoot trefoil growth in different conditions of toxic Al, as well as the selection of a more tolerant genotype to aluminum permitted a significant increase in this defense mechanism.
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Campbell, Jackie Bridget. "Increasing wheat hardness locus functionality by increasing puroindoline copy number and introduction of novel alleles." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/campbell/CampbellJ0507.pdf.
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Karhoff, Stephanie. "Characterization of a Major Quantitative Disease Resistance Locus for Partial Resistance to Phytophthora sojae." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555429203649991.
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Stollar, Rachel. "Fine mapping of the nuclear restorer locus for cytoplasmic male sterility in Brassica napus." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34014.
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This thesis will discuss the 'Polima' cytoplasmic male sterility (CMS) system (pol) in Brassica napus (Canola) and detailed genetic mapping of the region surrounding restorer gene ( Rfp) for that system This fine mapping of the Rfp region will facilitate efforts to clone the gene that will eventually lead to its characterization. Knowledge of the structure of Rfp will provide insight in the molecular mechanisms governing mitochondrial gene statement as well as pollen production and may lead to the development of alternative methods of pollination control. In addition, it is possible that nuclear restorer genes for other CMS systems in other crops may be similar to that of the 'Polima' system.Map based cloning requires the identification of DNA markers tightly linked to Rfp. Two PCR based markers which are located on either side of Rfp were developed. These markers allowed facile screening of a large population.
RFLP markers used in this study are based on the synteny between B. napus and the well known crucifer A. thaliana. (Abstract shortened by UMI.)
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Henry, Julie Leanna. "Mating-type Locus Characterization and Variation in Pyrenophora semeniperda." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5948.
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Pyrenophora semeniperda is a generalist fungal pathogen that occurs primarily on monocot seed hosts. It is in the phylum Ascomycota, which includes both self-compatible (homothallic) and self-incompatible (heterothallic) species. Homothallic fungal species contain complementary mating-type (MAT) idiomorphs in a single unikaryotic strain, while heterothallic strains contain a single MAT idiomorph requiring interaction between strains of complementary mating-types for sexual reproduction to occur. Because the majority of P. semeniperda strains contained either MAT1 or MAT2, this species was provisionally categorized as heterothallic. However, many strains contain both MAT idiomorphs and appear to be homothallic. These results warranted a closer look at the MAT idiomorphs and the structure of the P. semeniperda genome in order to assure accurate characterization of the MAT locus. Additionally, an assessment of the geographic distribution of MAT idiomorphs provides us with insight into the genetic diversity of P. semeniperda and the reproductive strategies that it employs. In this study, we characterized the P. semeniperda MAT locus and assessed the idiomorph distribution of 514 isolates from 25 P. semeniperda populations collected from infected Bromus tectorum (cheatgrass) seeds. Additionally, we used simple sequence repeat (SSR) and MAT idiomorph length polymorphisms to demonstrate the existence of dikaryotic strains and pseudohomothallism in this fungus. We identified a unique variable number tandem repeat (VNTR) within each idiomorph of the MAT locus of P. semeniperda. Presence of the VNTR in all MAT loci analyzed from strains collected in the Intermountain West suggests ancient proliferation of this repeat. The persistence and effectiveness of P. semeniperda strains in the cheatgrass pathosystem depend not only on the density of the fungus in the soil, but also on the genetic heterogeneity of each population. Our study suggests that P. semeniperda genetic diversity is increased both through MAT locus-dependent sexual reproduction and asexually through anastomosis.
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Tonon, Brenda Cristye. "Compatibilidade simbiótica e caracterização de rizóbios de Lotus spp., isolados de solos do Rio Grande do Sul." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/17336.
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Espécies do gênero Lotus têm sido utilizadas como plantas forrageiras no Estado do Rio Grande do Sul (RS). No entanto, tem sido observada certa especificidade hospedeira na simbiose rizóbio-Lotus quando se utiliza L. corniculatus em substituição a L. subbiflorus, na implantação de pastagens com essas leguminosas, e vice versa. Sendo assim, a hipótese deste trabalho é que, nos solos do estado, existem rizóbios nativos que formam diferentes grupos de compatibilidade simbiótica com espécies de Lotus. Para avaliação da compatibilidade simbiótica entre rizóbios nativos, isolados de solos do RS, e plantas de L. corniculatus, L. uliginosus, L. subbiflorus e L. glaber, foram realizadas a avaliação da inoculação cruzada em tubos de ensaio, em lampadário, e em vasos tipo "Leonard", em casa de vegetação. Também se avaliou a compatibilidade simbiótica, em tubos de ensaio, de 159 rizóbios obtidos de L. corniculatus, L. uliginosus, L. glaber e L. subbiflorus que foram inoculados em plantas das quatro espécies de Lotus, avaliando-se a nodulação e a fixação de nitrogênio (N2). No experimento em casa de vegetação, com vasos "Leonard", avaliaram-se quatro isolados de rizóbios nativos quanto à eficiência na fixação simbiótica de N2 em plantas das quatro espécies de Lotus. Estes rizóbios também foram caracterizados geneticamente por comparação do perfil eletroforético dos produtos de amplificação do DNA genômico, pela reação em cadeia da polimerase com os oligonucleotídeos iniciadores BOX e ERIC. Os isolados de rizóbios nativos UFRGS Lg5, Lg109 e Lg111, obtidos de L. glaber, foram ineficientes na simbiose com plantas de L. subbiflorus e L. uliginosus sendo eficientes apenas em plantas de L. corniculatus e L. glaber. No entanto, as estirpes EEL698, U512 e o isolado Lc340 foram capazes de induzir a formação de nódulos e de fixar N2 em simbiose com todas as espécies de Lotus estudadas. Isto evidencia a existência, nas amostras de solo das localidades estudadas no RS, de rizóbios nativos eficientes em plantas de ambos os grupos de compatibilidade simbiótica, com potencial para serem usados em inoculantes funcionais para espécies de Lotus. Observou-se também que existem rizóbios potencialmente parasitas tanto para plantas das espécies L. corniculatus e L. glaber como para L.uliginosus.Lotus sp. species have great potential to be cultivated as forage plants in Rio Grande do Sul State (RS), Brazil. However, some symbiotic specificity has been observed in the Rhizobia-Lotus symbiosis when L. corniculatus is replaced by L. subbiflorus and vice versa. So, this work's hypothesis is that in the soils of RS there are native Rhizobia that form different groups with Lotus species. To evaluate the symbiotic compatibility among native Rhizobia, isolated from RS soils, and plants of L. corniculatus, L. uliginosus, L. subbiflorus and L. glaber, were made the evaluation of the crossinoculation in tubes, under laboratory conditions, as well as in Leonard Jars under greenhouse conditions. In tubes, the symbiotic compatibility of 159 rhizobia, obtained from of L. corniculatus, L. uliginosus, L. glaber and L. subbiflorus plants, that were inoculated on plants of these four Lotus species and evaluated on their capacity to form nodules and fixing N2. In the green house experiments, whit Leonard jars, four native rhizobia isolates were evaluated regarding to the efficiency of symbiotic nitrogen fixation in association with plants of the four Lotus species studied. Those rhizobia also were genetically characterized by PCR fingerprinting of genomic DNA using primers BOX and ERIC. Native Rhizobia isolates obtained from L. glaber (UFRGS Lg5, Lg109 e Lg111) didn't establish an effective symbiosis with L. subbiflorus and L. uliginosus, being efficient only when inoculated on L. corniculatus and L. glaber plants. However, the strains EEL 698 and U512 as well as the isolate Lc 340 were able to induce nodulation and fixing N2 in symbiosis with all the studied Lotus species. This find points to the existence, in the state's soil samples, of native Rhizobia efficient in plants of both symbiotic compatibility groups, whit potential to be used as inoculant for those Lotus species. It was observed that there are some native Rhizobia potentially parasitic with L. corniculatus and L. glaber and also L. uliginosus.
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Lindsay, Robert C. "QUANTITATIVE AND MOLECULAR ANALYSIS OF HABITUATION AT THE MAIZE r1 LOCUS." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5655.
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Epigenetics is the study of heritable changes in phenotypes that are not the result of changes in DNA sequence. Examples of epigenetic affecters include methylation changes, chromatin modifications, transcription factors, and RNA-based changes. The molecular mechanisms behind epigenetic changes are not fully understood. Canalization is the buffering of gene expression against environmental changes over time, while habituation is semi-stable expression change over time due to selection. This work characterized the molecular changes associated with the kernel color changes of the R-sc:86-17pale allele at the maize red color1 (r1) locus to determine if the changes are epigenetic in nature. The research; 1) quantified the color differences between the progenitor and habituated sublines; 2) Determined that there are not sequence differences between the progenitor and habituated sublines at the 3` end of the Sc||nc1 gene that could account for changes in seed color; 3) and examined the cytosine methylation patterns at the 3` end of the Sc||nc1 gene of the habituated sublines and the progenitor to determine whether there are methylation differences that correspond with the kernel color changes. Quantification of the kernel colors of the R-sc:86-17pale selection sublines showed that there was a statistically significant difference in kernel color. The identical sequence of the R-sc:86 line and the R-sc:86-17pale Lightest and R-sc:86-17pale Darkest sublines at the 3` end of the Sc||nc1 gene is evidence that the kernel color change is not driven by differences in sequence within the r1 gene. The methylation data suggests that some methylation differences in the R-sc:86-17pale Lightest and R-sc:86-17pale Darkest sublines are present, and suggests that the molecular basis of the kernel color is epigenetic in nature.
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Wargachuk, Richard Burns. "Fine mapping and functional analysis of the radish Rfo nuclear restorer locus." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81454.
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Cytoplasmic male sterility (CMS) is a widespread, maternally inherited trait that results in an inability of plants to produce functional pollen. The Ogura CMS system originated in radish, but has since been transferred to, and confers male sterility on, plants in the related genus Brassica . A gene which restores male fertility is needed for the Ogura CMS system to be exploited commercially for hybrid seed production in oilseed species such as Brassica napus. The restorer gene Rfo is a dominant radish nuclear gene that restores the male fertility to plants with Ogura cytoplasm. This gene has been transferred into Brassica napus through intergeneric crosses; however the introgressed segment of radish DNA contains an unknown number of genes, some of which confer undesirable traits, such as an elevated content of seed glucosinolates, antinutritive compounds that render the seed meal unusable as animal feed. A fine scale linkage map of the region in radish containing Rfo was constructed, and a map-based cloning approach relying on synteny between radish and Arabidopsis was used to clone Rfo. A radish gene encoding a 687 amino acid protein with a predicted mitochondrial targeting presequence was found to confer male fertility upon transformation into Ogura CMS B. napus . This gene, codes for a pentatricopeptide repeat (PPR)-containing protein with multiple, in this case 16, PPR domains. Two similar genes that do not appear to function as Rfo flank this gene. A transcript representing a non-functional allele (rfo) was detected in sterile radish plants. Comparison of the Rfo region with the syntenic Arabidopsis region indicates that a PPR gene is not present at the Rfo-equivalent site in Arabidopsis , although a smaller and related PPR gene is found about 40 kb from this site.
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Aryamanesh, Nader. "Chickpea improvement through genetic analysis and quantitative trait locus (QTL) mapping of ascochyta blight resistence using wild Cicer species /." Connect to this title, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0072.
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Sicard, Ophélie. "Déterminants génétiques impliqués dans les interactions Arabidopsis thaliana/Potyvirus : identification de déterminants de plante et de virus impliqués dans le développement de symptômes." Bordeaux 2, 2007. http://www.theses.fr/2007BOR21454.
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Le criblage d'une collection d'accessions d'A. Thaliana, représentative de la diversité génétique de l'espèce avec des isolats variés du virus de la mosaique de la laitue (LMV) et du virus de la Sharka (PPV), deux potyvirus, a permis d'établir une base de données de phénotypes allant de résistances totales à des infections généralisées symptomatiques. L'analyse du déterminisme génétique du phénotype d'infection généralisée symptomatique identifié dans un grand nombre d'accessions vis-à-vis du PPV, réalisée à l'aide de populations de lignées recombinantes fixées, a permis d'identifier plusieurs QTL vis-à-vis des caractères "symptômes" et "accumulation virale". Cependant nous avons montré qu'il n'y avait qu'une faible corrélation entre ces deux caractères. L'un de ces QTL PS11 a été confirmé par l'utilisation de lignées quasi-isogéniques et sa cartographie fine a été initiée en vue de son clonage positionnel. Pour le QTL PS13, nous avons identifié dans l'intervalle génétique qui le contient le gène codant pour le facteur d'initiation de la traduction elF4G, connu pour être impliqué dans les interactions plante/potyvirus. L'hypothèse de l'absence ou de la non-fonctionnalité de ce facteur et de son influence sur la sévérité des symptômes est discutée. De plus, plusieurs déterminants viraux impliqués dans l'apparition des symptômes ont pu être identifiés Ce travail ouvre des perspectives pour d'une part des études d'association phénotype/génotype qui pourront être effectuées sur les accessions symptomatiques identifiées dans ce travail, et d'autre part des analyses fonctionnelles réalisées sur les déterminants de plante et viraux identifiésThe screening of an Arabidopsis thaliana core collection representing 96 % of the species genetic variability was performed with different isolates of the Lettuce mosaic virus (LMV) and of the Plum pox virus (PPV). It lead to the identification/observation of a large diversity of phenotypes, from total resistance to symptomatic susceptibility. The genetic determinants for symptoms were studied in two related recombinant inbred line (RIL) populations, Cvi/Ler and Col/Ler. Several QTLs (quantitative trait locus) linked to viral accumulation and symptomatic susceptibility were identified whereas a weak correlation traits was detected. The PS11 QTL as identified in both populations and confirmed in isogenic lines ; its fine-mapping was under course. A candidate gene approach focalised on the PS13 QTL region where the gene coding for the translation initiation factor eLF4G is mapping. The hypothesis that the abscence or the non-fonctionnality of this factor known for its implication in plant/potyvirus interactions is determinant for symptom was tested. Besides, different viral determinants implied in symptom development have been identified. This work offers new opportunities for association studies and for functionnal analysis of plant/virus interactions
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Arcade, Anne. "Detection de locus controlant des caracteres quantitatifs dans un plan de croisement factoriel : application au meleze." Orléans, 1999. http://www.theses.fr/1999ORLE2024.
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Les arbres forestiers presentent des temps de generation longs et de nombreux caracteres interessants pour l'ameliorateur ne sont evalues avec fiabilite qu'au stade adulte. La recherche de criteres de selection precoce est donc vivement souhaitable. Un plan de croisement factoriel entre 12 melezes d'europe (larix decidua) et 12 melezes du japon (larix kaempferi) installe et evalue pour des caracteres de croissance, de forme, et de densite du bois a ete choisi comme materiel. Dans un premier temps, la relation entre le niveau d'heterozygotie des melezes hybrides et leur performance pour les differents caracteres a ete etudiee. Des correlations significatives entre distance genetique entre parents et performance des hybrides ont ete observees pour certains caracteres. Dans un deuxieme temps, une recherche de qtl (quantitative trait loci) a ete entreprise. Des cartes genetiques du meleze d'europe et du meleze du japon ont d'abord ete construites (marqueurs aflp, rapd, issr). La detection de qtl a ensuite ete menee de deux facons differentes. La premiere approche a consiste a detecter des qtl dans une serie de familles issues d'un meme parent: quelques regions du genome presentant des qtl lies a la croissance et a la densite du bois ont ete observees. Une seconde approche a consiste a rechercher des liens entre la presence d'un allele particulier au marqueur chez des parents, et une performance particuliere des familles engendrees. De nombreux qtl potentiels ont ete detectes. Une partie d'entre eux a ete validee au niveau individuel. Cette methode est susceptible de reveler une part plus importante des qtl impliques dans les caracteres. L'integration de cette methodologie dans le cadre d'une selection assistee par marqueurs est proposee, afin de guider le choix des geniteurs ou de multiplier vegetativement les individus presentant les alleles favorables aux qtl.
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Salgon, Sylvia. "Déterminisme génétique de la résistance au flétrissement bactérien chez l'aubergine et applications en sélection variétale." Thesis, La Réunion, 2017. http://www.theses.fr/2017LARE0010/document.
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La culture de l’aubergine est confrontée au flétrissement bactérien, maladie causée par le complexe d’espèces Ralstonia solanacearum. La résistance variétale est la méthode la plus efficace pour contrôler cette maladie. Un QTL majeur (ERs1) a précédemment été cartographié dans une population de lignées recombinantes (RIL) issue du croisement aubergine sensible (S) MM738 × aubergine résistante (R) AG91-25. Initialement, ERs1 a été détecté avec 3 souches du phylotype I, alors qu’il est contourné par la souche PSS4 de ce même phylotype. Les objectifs de cette thèse étaient (i) de préciser la position d’ERs1 et de définir son spectre d’action, (ii) d’identifier d’autres QTLs contrôlant les souches virulentes sur AG91-25, et (iii) d’introgresser certains de ces QTLs dans des cultivars S. Pour cela, 2 populations d'haploïdes doublés (HD), MM152 (R) × MM738 (S) et EG203 (R) × MM738 (S), ont été créées. La population RIL a été phénotypée avec 4 souches supplémentaires appartenant aux phylotypes I, IIA, IIB et III, tandis que les populations HD l’ont été avec les souches virulentes PSS4 et R3598. Les analyses de cartographie génétique ont confirmé l’existence d’ERs1 (renommé EBWR9), défini sa position sur le chromosome (chr) 9 et validé son contrôle spécifique de 3 souches du phylotype I. EBWR2 et EBWR14, 2 autres QTLs à large spectre, ont été détectés sur les chr 2 et 5. Les analyses QTL ont mis en évidence un système de résistance de type polygénique chez EG203. Le transfert de la résistance dans 2 cultivars locaux a été initié et a permis l’introgression d’EBWR9 et d’EBWR2. Ces résultats ouvrent des perspectives quant à la création de variétés à large spectre de résistanceEggplant cultivation is confronted by the bacterial wilt disease caused by the Ralstonia solanacearum species complex. Breeding resistant cultivars is the most effective strategy to control the disease but is limited by the pathogen’s extensive genetic diversity. A major QTL (ERs1) was previously mapped in a recombinant inbred lines (RIL) population from the cross of susceptible (S) MM738 × resistant (R) AG91-25 lines. ERs1 was originally found to control 3 strains from phylotype I, while being ineffective against the strain PSS4 from the same phylotype. The objectives of this thesis was to (i) clarify the position of ERs1 and define its spectrum of action, (ii) found other QTLs, promptly to control virulent strains on AG91-25 and (iii) introgress some of the QTLs into two S cultivars. For this purpose, the new doubled haploid (DH) populations MM152 (R) × MM738 (S) and EG203 (R) × MM738 (S) were created. The RIL population was phenotyped with 4 additional RSSC strains belonging to phylotypes I, IIA, IIB and III and the DH populations were phenotyped with virulent strains PSS4 and R3598. QTL mapping confirmed the existence of ERs1 (renamed EBWR9), defined its position on chromosome (chr) 9 and validated its specific control of 3 phylotype I strains. EBWR2 and EBWR14, 2 broad-spectrum resistance QTLs, were detected on chr 2 and 5. QTL analysis reveals a polygenic system of resistance in EG203. The transfer of resistance into 2 local cultivars was initiated and allowed the introgression of EBWR9 and EBWR2 QTLs through a backcross scheme. These results offer perspectives to breed broad-spectrum R cultivars
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Nishio, Haruki. "Seasonal analysis of histone modifications in a natural population of Arabidopsis halleri." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/216171.
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Nascimento, Mariá Cristina Vasconcelos. "Uma heurística GRASP para o problema de dimensionamento de lotes com múltiplas plantas." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-26042007-151429/.
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O problema de dimensionamento de lotes, objeto desse estudo, considera um ambiente composto por múltiplas plantas independentes, múltiplos itens e múltiplos períodos. O ambiente de produção tem capacidade limitada e as plantas podem produzir os mesmos itens. Cada planta tem uma demanda própria e é permitida a transferência de lotes entre as plantas, o que envolve um certo custo. Este problema tem como caso particular o de dimensionamento de lotes com máquinas paralelas. O objetivo desta dissertação é propor uma heurística baseada na meta-heurística GRASP (Greedy Randomized Adaptive Search Procedures). Além disso, uma estratégia path relinking foi incorporada ao GRASP como uma fase de melhoria do algoritmo. Para verificar a eficiência da heurística proposta, os seus resultados são comparados aos da literatura tanto no caso de máquinas paralelas quanto no de múltiplas plantas. Como resultado, o problema de múltiplas plantas obteve melhores resultados quando comparado aos da heurística da literatura. Com relação ao problema de máquinas paralelas, a heurística proposta se mostrou competitivaThe lot sizing problem, which is the aim of this study, considers an environment consisting of multiple independent plants, multiple items and multiple periods. The production environment has limited capacity and the plants can produce the same items. Each plant has its own demand and the lot transfers between the plants are permitted, which involves a certain cost. This problem has as a particular case the parallel machines lot sizing problem. The objective of this dissertation is to propose a heuristic based on the GRASP (Greedy Randomized Adaptive Search Procedures). Furthermore, a path relinking phase is embedded in the GRASP to obtain better performance. To verify the efficiency of the proposed heuristic, its results were compared with the literature as for the multi-plant as for parallel machines problem. Computational tests showed that the proposed heuristic performed better than other literature heuristic concerning the multiplant problem. Concerning the parallel machines, the heuristic is competitive
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Silva, Daniel Henrique. "Métodos híbridos para o problema de dimensionamento de lotes com múltiplas plantas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-22042013-111213/.
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Neste trabalho, apresentamos um estudo sobre o problema de dimensionamento de lotes com múltiplas plantas, múltiplos itens e múltiplos períodos. As plantas têm capacidade de produção limitada e a fabricação de cada produto incorre em tempo e custo de preparação de máquina. Nosso objetivo é encontrar um plano de produção que satisfaça a demanda de todos os clientes, considerando que a soma dos custos de produção, de estoque, de transporte e de preparação de máquina seja a menor possível. Este trabalho tem duas contribuições centrais. Primeiramente, propomos a modelagem do problema de dimensionamento de lotes com múltiplas plantas utilizando o conceito de localização de facilidades. Para instâncias de pequena dimensão, os testes computacionais mostraram que a resolução do problema remodelado apresenta, como esperado, resultados melhores que o modelo original. No entanto, seu elevado número de restrições e de variáveis faz com que as instâncias de maiores magnitudes não consigam ser resolvidas. Para trabalhar com instâncias maiores, propomos um método híbrido (math-heurística), que combina o método relax-and-fix, com a restrição de local branching. Testes computacionais mostram que o método proposto apresenta soluções factíveis de boa qualidade para estas instânciasIn this work, we present a study about the multi-plant, multi-item, multi-period lot-sizing problem. The plants have limited capacity, and the production of each item implies in setup times and setup costs. Our objective is to find a production plan which satisfies the demand of every client, considering that the sum of the production, stocking, transport and setup costs is the lowest possible. This work has two main contributions. Firstly, we propose the multi-plant lot-sizing problem modeling using the facility location concept. For small dimension problems, computational tests showed that the remodeled problem resolution presents, as expected, better results than the original model. However, the great number of restrictions and variables make bigger instances to be intractable. To work with the bigger dimension instances, we propose a hybrid method (math-heuristic), which combines the relax-and-fix method and the local branching restriction. Computational tests show that the proposed math-heuristic presents good quality feasible solutions for these instances
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Gonçalves, Paula Vieira Cristina Alexandra. "Population genetic studies of the S-locus gene family and other loci in self-compatible and self-incompatible populations of the plant Antirrhinum." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/10925.
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In this work the mating system of several populations and species of Antirrhinum were established in the glasshouse. Levels of DNA diversity were estimated based on cyc and fil1 nuclear genes. Both genes are shown to belong to gene families. In these gene families, some members are very similar, which makes difficult to determine orthology. In the cases where orthology is not a problem, low levels of nucleotide diversity were found. Therefore the effect of the mating system on genetic diversity could not be tested. An unexpected finding of very little divergence between several Antirrhinum species, Digitalis, and the more distantly related genus Verbascum was also found for genes of the cyc and fill gene families. The generality of this pattern was addressed by extending these studies to fil2, far, globosa and Adh genes. Evidence is shown that these genes are also members of gene families in Antirrhinum. For fil2, far, and globosa, very similar sequences were found in Antirrhinum and Verbascum. For Adh I could not determine orthology because repeated gene duplication and loss of elements in this gene family has occurred in the Antirrhinum and Verbascum lineages. Several hypotheses that could account for the low diversity and divergence are discussed. In Antirrhinum, self-incompatibility is controlled by a gametophytic system. The gene responsible for pistil self-incompatibility is the S-locus that encodes basic glycoproteins with ribonuclease activity. High levels of variability are observed, consistent with frequency-dependent selection. The putative targets of selection are those regions, such as the hypervariable regions of this gene, that may be involved in specificity determination. In order to gather evidence on whether these regions are hypervariable because they are the target of selection, or merely regions of relaxed selective constraint, we have partially sequenced Antirrhinum S-alleles and analysed their level and pattern of nucleotide diversity. Within each allelic type, low levels of diversity were observed. Similar alleles were found in self-compatible and self-incompatible species, suggesting that the Antirrhinum group evolved recently.
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Nascimento, Wanderleia Holanda Salgado do. "Impactos ambientais provocados pela implantação de loteamentos urbanos na área de proteção ambiental Tarumã/Ponta Negra no município de Manaus-AM." Universidade Federal do Amazonas, 2009. http://tede.ufam.edu.br/handle/tede/2605.
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The study aimed to identify the environmental impacts caused during the implementation and operation of land divisions in the APA, to propose adequate procedures for environmental licensing of the activity, along with environmental agencies. The identification and qualitative characterization of the environmental impacts have been realized from the use of the method List of Control ("Check-List"), which consists in the glimpse and the list of consequences (impacts), when is considerate the transformative potential of the environment physical, biotic and anthropic causes (impacting activities). To facilitate their evaluation, the method of Leopold Matrix, which facilitated the visualization and assessment of impacts on different components of the environment. To identify waterways, was used 1:50,000 basemap IBGE, using ArcGIS 9.3 softwere and Cadastral base of the City of Manaus, SEMEF scale of 1:2,000. After systematic data above was used to effect the SRTM image density of the watercourses in the area of Urban APA. For the spatio-temporal, multispectral images were used TM / Landsat 5, QuickBird, in the period that comprises the years 2001, 2005 and 2008 as well as aero-photogrammetric data (aerial photographs) for analysis of the temporal evolution of environmental degradation APA. Possibilitaramde Studies show that from the viewpoint of environmental impacts are common to the "Sizes", which differs only in intensity and magnitude of them. This information was evident when were making inquires about the impacts, which was concentrated in lots of different sizes: two medium-sized and two large-sized array and qualitative and quantitative. It was demonstrated that the allotments of Large Size with low population density tend to cause relatively less significant impacts than others who occupy smaller areas, considered in Small and / or Medium-sized, however, occupied more intensively. It was verified that the housing lot makers are responsible only for the suppression of plant part of the blending infrastructure (installation of building site, road system and recreation area), leaving the responsibility of the owners, the deforestation of the lots. This procedure revealed that a large portion of deforestation is the result of occupation of the plot, made without authorization from the Environmental Agency, disregarding the criteria of the legislation and no monitoring of construction, disrespecting the legal reserve area and interventions in the vast majority of Permanent Preservation Areas -APP. On the temporal analysis, the supervised classification was performed on Total Area of the APA, allowing the calculation of the dynamics and spatial-temporal process of deforestation, with allowance for the analysis of the study area which is its urban area. In the period 2006-2008, the rate of deforestation over the area of the BB was 63.26%. However, over the period analyzed, there was a reduction, an increase of only 6.36% and rate of progression was 59.78%. Analyzing the evolution of deforestation in the Urban Area of the APA, it was found that the main vectors of deforestation were: exploration of mineral products for immediate use in construction, crops, vegetation removal activities for industrial facilities, as well as invasions of areas, than the allotments.
O estudo teve como objetivo identificar os impactos ambientais provocados na fase de implantação e operação de loteamentos na APA, visando propor adequação nos procedimentos de licenciamento ambiental da atividade, junto aos órgãos ambientais. A identificação e a caracterização qualitativa dos impactos ambientais foram realizados a partir da utilização do método Listagem de Controle ( Check-List ), que consiste, no vislumbramento e na listagem de conseqüências (impactos ambientais), quando se considera o potencial transformador do ambiente físico, biótico e antrópico, de causas (atividades impactantes). Para facilitar sua avaliação foi utilizado o método de Matriz de Leopold, que facilitou a visualização e a valoração dos impactos sobre os diferentes componentes do ambiente. Para identificação dos cursos d água, foi utilizado base cartográfica na escala 1:50.000 do IBGE, utilizando o Softwere ARCGIS 9.3, bem como base Cadastral da Cidade de Manaus, escala 1:2.000 da SEMEF. Após sistematização dos dados acima citados, foi utilizado imagem SRTM para efetivar o adensamento dos cursos d água da área Urbana da APA. Para a dinâmica espaço-temporal, foram utilizadas imagens multiespectrais Sensores TM/LANDSAT 5, QUICKBIRD, no período compreendendo os anos de 2001, 2005 e 2008, bem como dados aero-fotogramétricos (fotografias aéreas), para análise da evolução temporal da degradação ambiental da APA. Os estudos possibilitaramde demonstrar que do ponto de vista ambiental, os impactos são comuns aos diferentes Portes , diferenciado-se apenas na intensidade e na magnitude dos mesmos. Essa informação foi evidenciada durante a fase de levantamento dos impactos, que foi concentrado em loteamentos de portes diferenciados: dois de porte médios e 2 de porte grande e na matriz qualitativa e quantitativa. Ficou evidenciado que loteamentos de Porte Grande com pouca densidade populacional tendem a causar impactos relativamente menos significativos do que outros que ocupam áreas menores, considerados de Pequeno e/ou Médio Porte, porém, ocupados de forma mais intensa. Foi constatado ainda, que os loteadores são responsáveis apenas pela supressão vegetal da parte de infra-estrutura do loteamento (implantação de canteiro de obras, sistema viário e área de lazer), deixando sob a responsabilidade dos proprietários, o desmate dos lotes. Esse procedimento evidenciou que uma grande parcela do desmatamento é resultante da ocupação dos lotes, feito sem autorização do Órgão Ambiental, desrespeitando os critérios da legislação e sem acompanhamento da construtora, desrespeitando a área de reserva legal e intervenções na grande maioria das Áreas de Preservação Permanente APP. Quanto a análise temporal, a classificação supervisionada foi realizada na Área Total da APA, possibilitando calcular a dinâmica e o processo espaço-temporal de desflorestamento, dando subsídio para análise da área objeto de estudo que é a sua Área Urbana. No período de 2006 a 2008, a taxa de desflorestamento em relação a área total da APA foi de 63,26%. Porém, em relação ao período analisado, houve uma redução, com incremento de apenas 6,36% e índice de evolução de 59,78%. Na análise da evolução do desflorestamento na Área Urbana da APA, constatou-se que os principais vetores de desflorestamento foram: exploração de produtos minerais para emprego imediato na construção civil, culturas agrícolas, atividades supressão vegetal para instalações industriais, bem como invasões de áreas, além dos loteamentos foco desta pesquisa
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Van, Ghelder Cyril. "Le locus de résistance Ma des Prunus vis-à-vis des nématodes à galles : Originalité structurale et évolution dans la famille des NBS-LRRs chez les plantes." Electronic Thesis or Diss., Université Côte d'Azur (ComUE), 2019. http://www.theses.fr/2019AZUR6006.
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Les nématodes à galles, Meloidogyne spp., sont des ravageurs extrêmement polyphages qui, à l’échelle mondiale, occasionnent de graves dommages aux plantes. La résistance génétique spécifique des plantes aux maladies et ravageurs s’appuie principalement sur les gènes de la famille des récepteurs NBS-LRR (ou NLRs), regroupant les TNLs, CNLs et RNLs. Chez les Prunus, le gène Ma du prunier appartient à la sous-famille des TNLs et confère une résistance à toutes les espèces de Meloidogyne testées, alors que le gène RMja de l’amandier exprime un spectre de résistance (R) plus restreint vis-à-vis de ces ravageurs. De plus, la protéine Ma présente une région C-terminale particulière constituée de cinq domaines répétés, désignés domaines post-LRR (PLs). Notre travail de thèse a caractérisé l’originalité et la distribution de cette région à travers de nombreux protéomes de plantes et a identifié la relation génétique entre les gènes Ma et RMja.Nous avons tout d’abord étudié la fréquence, la distribution et les caractéristiques structurales des gènes TNL et des domaines PL dans le génome du pêcher, génome de référence des Rosaceae. Les domaines PL, retrouvés chez les deux tiers des 195 TNLs identifiés, nous ont permis d’établir des signatures améliorant la détection de ce domaine, jusqu’alors peu étudié, dans divers génomes d’Angiospermes. Nous avons pu établir que le domaine PL est spécifique aux TNLs et qu’il est retrouvé dans des proportions similaires à celle établie chez le pêcher. Par ailleurs, les TNLs disposant de domaines PL multiples sont rares chez les plantes étudiées. La structure à cinq domaines répétés est probablement unique à Ma et ses orthologues et a vraisemblablement été héritée de leur ancêtre commun dans l’ordre des Rosales. Nous avons ensuite étudié le répertoire des NBS-LRRs chez les conifères (Gymnospermes), groupe taxonomique ancien, dont les données sur cette famille de gènes étaient parcellaires. En analysant sept transcriptomes de référence, nous avons pu établir que l’arsenal des NBS-LRRs chez les conifères était large et varié mais, étonnamment, qu’aucun domaine PL précédemment défini n’y était présent. L’examen de protéomes de plantes plus anciennes a montré que seul le Ginkgo biloba portait quelques signatures PL. Ces observations suggèrent une acquisition partielle précoce du domaine chez les plantes à graines et une expansion adaptative chez les Angiospermes. En complément, nous avons montré que les conifères, tout comme les Rosaceae, possèdent de nombreux RNLs et TNLs. En étendant notre étude à diverses plantes terrestres, nous avons mis en évidence un rapport moyen de 1:10 reliant les effectifs de RNLs et de TNLs à travers les divers génomes étudiés. Nous avons finalement conduit une cartographie haute résolution du gène RMja chez l’amandier. En nous appuyant sur une banque BAC, RMja a été localisé dans le cluster de résistance Ma et l’orthologue de Ma est de très loin le meilleur candidat. La comparaison de séquence entre les régions orthologues du locus Ma, chez le prunier (spectre R complet), l’amandier (spectre R incomplet) et le pêcher (spectre R nul) a mis en évidence une structure conservée unique des trois orthologues de Ma. Nos résultats suggèrent que le polymorphisme des répétitions du domaine PL sous-tend des interactions différentielles de résistance vis-à-vis des Meloidogyne et un mécanisme d’immunité original chez les plantes pérennes. Dans ces processus immuns de reconnaissance ou de signalisation, d’autres composants tels les RNLs pourraient être impliqués. Notre travail ouvre la voie à des approches comparative et fonctionnelle d’identification des déterminants moléculaires impliqués dans la résistance aux nématodes à gallesRoot-knot nematodes (RKNs), Meloidogyne spp., are extremely polyphagous pests that severely challenge plants worldwide and especially perennials. The specific genetic resistance of plants mainly relies on NBS-LRR receptor genes (or NLRs grouping TNL, CNL and RNL subfamilies) that are pivotal factors for control of pests and pathogens. In Prunus spp., the Ma plum TNL gene confers resistance to all RKNs tested, whereas the RMja almond gene displays a more restricted spectrum of resistance (R). Moreover, the Ma predicted protein shows a peculiar TNL structure due to a C-terminal region made of five repeated domains, designated post-LRR domains (PLs). In this context, this thesis work has characterised the originality and the distribution of this uncommon structure among diverse plant proteomes and has revealed the genetic relationship between the Ma and RMja genes.We first studied the frequency, distribution and structural characteristics of TNL genes and PL domains within the peach genome, the reference genome for Rosaceae. The finding of PL domains, which have been identified in two thirds of the 195 TNLs, allowed us to define specific motifs that improve the detection of this poorly known domain in Angiosperms. We found that the PL domain is specific of TNLs and is present in Angiosperm genomes in a proportion similar to the one established for peach. Besides, TNLs displaying multiple PL domains are rare in plants. The five-PL domain pattern is probably unique to Ma and its orthologues and was probably inherited from their common ancestor in the order Rosales. We then investigated the NBS-LRR repertoire of the conifers (Gymnosperms), an ancient taxonomic group, for which the data related to this gene family are unclear. By analysing seven reference transcriptomes, we highlighted a large and diverse NBS-LRR arsenal in conifers but, surprisingly, no PL signatures have been detected. The examination of ancient plant proteomes revealed that only Ginkgo biloba displayed a few PL signatures. Our results suggest that a partial acquisition of the PL domain occurred early in seed plants and was followed by an adaptive expansion in Angiosperms. Additionally, we showed that conifers and Rosaceae have numerous RNLs and TNLs. By enlarging our study to other land plant genomes, we uncovered an average ratio of 1:10 between RNLs and TNLs numbers.We finally carried out a high-resolution mapping of the RMja gene in almond. Using a BAC library, RMja was localised into the Ma resistance cluster and the Ma orthologue is by far the best candidate. The sequence comparison between three orthologous regions of the Ma locus, i.e. plum (complete R spectrum), almond (incomplete R spectrum) and peach (null R spectrum) highlighted a unique conserved structure of the Ma orthologues. Our results suggest that the polymorphism contained in the PL-domain repeats might underlie differential resistance interactions with RKNs and an original immune mechanism in woody perennials. In these immune processes for recognition or signalling, other components such as RNLs might be involved. This work paves the way for future comparative and functional approaches aiming to unravel the molecular determinants involved in the resistance to RKNs
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Lombardi, Simone Pacheco. "Estudo funcional de um locus de regeneração (Rg1) vindo de Solanum peruvianum, uma espécie selvagem relacionada ao tomateiro." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-22072008-161223/.
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A regeneração in vitro é bastante utilizada em processos biotecnológicos. No entanto, pouco se conhece sobre os mecanismos envolvidos na aquisição de competência para formação de novos órgãos. Em tomateiro (S. lycopersicum), a alta capacidade de regeneração in vitro é atribuída ao alelo Rg1, vinda de Solanum peruvianum, e que está presente na cv MsK (S. lycopersicum x S. peruvianum). Os genes de nanismo da cv Micro-Tom (MT) foram passados para MsK, obtendo-se, após 8 gerações de autofecundação (F8), a cv Micro-MsK. No presente estudo, após 6 gerações de retrocruzamentos (BC6Fn), criou-se MT-Rg1, com Rg1 isogênico a MT. Testes de regeneração in vitro mostraram que a formação de gemas caulinares adventícias para MT-Rg1 e Micro-MsK são equivalentes, evidenciando que a alta capacidade de regeneração de Micro-MsK é basicamente devido ao Rg1. Plantas MTRg1 apresentam freqüente formação de 3 cotilédones, excesso de ramificações caulinares e senescência atrasada, características ausentes nos parentais. Esses efeitos pleiotrópicos de Rg1 coincidem com aqueles descritos para alterações no hormônio citocinina. Testes de sensibilidade à citocinina e de tempo de senescência realizados por nós, bem como dosagem desse hormônio feita por outras equipes, descartaram essa hipótese. Enxertias recíprocas evidenciaram que a promoção da ramificação caulinar por Rg1 não é um sinal translocável, mas parece ser uma característica intrínseca do tecido. Rg1 também promoveu uma maior formação de raízes adventícias em estacas ex vitro, sugerindo que ele afeta o processo de competência para formação de órgãos em geral, e não somente a indução específica de gemas caulinares. Duplos mutantes entre Rg1 e mutantes com alteração na sensibilidade/metabolismo hormonal (dgt, brt e pro), ausência de ramificações caulinares (ls) e senescência acelerada (l) foram obtidos e testados quanto ao padrão de ramificações e à capacidade de regeneração in vitro. Além desses parâmetros, a presença de Rg1 suprimiu o fenótipo de folhas pouco recortadas do mutante hipersensível a giberelina (pro) e recuperou o sistema radicular pouco desenvolvido do mutante com baixa sensibilidade à auxina (dgt). Rg1 também foi capaz de reverter a ausência de ramificações laterais de ls, sendo que a mutação Me, o qual representa uma superexpressão de um gene do tipo KNOX, não foi capaz. Esse resultado sugere que Rg1 não é um gene do tipo KNOX, embora esses genes sejam considerados os principais controladores da competência. Analisando diferentes tipos de explantes em experimentos independentes, contatou-se que, em geral, as mutações brt (baixa sensibilidade a citocinina), dgt e ls diminuíram a capacidade de regeneração de Rg1, enquanto l aumentou. Rg1 mostrou-se particularmente epistático à mutação pro, revertendo o fenótipo de baixa formação de gemas caulinares desse mutante. Surpreendentemente, Rg1 provou ser mais sensível à auxina em testes de alongamento de segmentos de hipocótilos, sendo capaz de reverter o fenótipo do mutante dgt nesse mesmo teste. Em conjunto, esses resultados confirmam o papel de Rg1 na fase de aquisição da competência e sugerem uma interação dos hormônios giberelina e auxina nesse processo.The In vitro regeneration process is widely used in plant biotechnology. However, the mechanisms involved in the acquisition of competence for organ formation are hitherto unknown. In tomato (S. lycopersicum), the high capacity for in vitro regeneration is attributed to the Rg1 allele from S. peruvianum, which is present in the cv MsK (S. lycopersicum x S. peruvianum). The dwarfism genes of the cv Micro-Tom (MT) were transferred to MsK, and, after 8 generations of selfing (F8), the cv Micro-Msk was obtained. Here, after 6 generations of backcrosses (BC6Fn), we created the MT-Rg1, which has Rg1 isogenic to MT. Tests of in vitro regeneration showed that shoot formation in MT-Rg1 and Micro-MsK are equivalent, suggesting that the high capacity of regeneration of Micro-MsK is basically due to Rg1. Comparing MT-Rg1 with the control MT, we noticed a high frequency of 3 cotyledon formation, increased shoot branching and late senescence, which are absent in the parentals. These pleiotropic effects of Rg1 coincide with those described for plants with alterations in the hormone cytokinin. Tests of sensitivity for cytokinin and senescence behavior carried out by us, as well as dosage of that hormone made by other researches, discarded that hypothesis. Reciprocal grafting showed that the promotion of shoot branching by Rg1 is not a transmissible signal, but seems to be an inherent characteristic of the tissue. Rg1 also increases adventitious roots formation of ex vitro cuttings, suggesting that it affects the process of competence, which is common for shoots and roots, instead of the specific induction of shoots. Double mutants between Rg1 and mutants with alteration in the sensitivity/metabolism of plant hormones (dgt, brt and pro), as well as mutants with absence of shoot branching (ls) and accelerated senescence (l) were obtained and tested for the capacity of in vitro regeneration. The presence of Rg1 suppressed the phenotype of less dissected leaves of the mutant hypersensitive to gibberrellin (pro) and rescued the phenotype of poor developed root system of the mutant with low auxin sensitivity (dgt). Rg1 was also able to revert the absence of axillary shoot formation in ls, whereas the mutant Me, which represents an over expression of a KNOX gene was not. This result suggests that Rg1 is not a KNOX gene, although those genes are considered the main controllers of the competence. Analyzing different types of explants in independent experiments, it was verified that, in general, the mutations brt (low sensibility to cytokinin), dgt and ls decreased the regeneration capacity of Rg1, while l increased it. Rg1 was particularly epistatic to the pro mutation, reverting the phenotype of little shoot formation of that mutant. Surprisingly, Rg1 proved to be more sensitive to auxin in the hypocotyl segment elongation test, being able to revert the phenotype of the mutant dgt in the same test. Together, these results confirm the role of the Rg1 in the process of acquisition of the competence and suggest an interaction of the hormones gibberellin and auxin in this process.
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Aryamanesh, Nader. "Chickpea improvement through genetic analysis and quantitative trait locus (QTL) mapping of ascochyta blight resistence using wild Cicer species." University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0072.
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[Truncated abstract] The genetics of ascochyta blight resistance was studied in five 5 x 5 half-diallel cross sets involving seven genotypes of chickpea (ICC 3996, Almaz, Lasseter, Kaniva, 24B-Isoline, IG 9337 and Kimberley Large), three accessions of Cicer reticulatum (ILWC 118, ILWC 139 and ILWC 184) and one accession of C. echinospermum (ILWC 181) under field conditions. Both F1 and F2 generations were used in the diallel analysis. Almaz, ICC 3996 and ILWC 118 were the most resistant genotypes. Estimates of genetic parameters, following Hayman's method, showed significant additive and dominant gene actions. The analysis also revealed the involvement of both major and minor genes. Susceptibility was dominant over resistance to ascochyta blight. The recessive alleles were concentrated in the two resistant chickpea parents ICC 3996 and Almaz, and one C. reticulatum genotype ILWC 118. High narrow-sense heritability (ranging from 82 to 86% for F1 generations, and 43 to 63% for F2 generations) indicates that additive gene effects were more important than non-additive gene effects in the inheritance of the trait and greater genetic gain by breeding resistant chickpea cultivars using carefully selected parental genotypes. Current simple leaf varieties are often susceptible to ascochyta blight disease whereas varieties of other leaf types range from resistant to susceptible. The inheritance of ascochyta blight resistance and different leaf types and their correlation were investigated in intraspecific progeny derived from crosses among two resistant genotypes with normal leaf type (ICC 3996 and Almaz), one susceptible simple leaf type (Kimberley Large) and one susceptible multipinnate leaf type (24 B-Isoline). ... An interspecific F2 mapping population derived from a cross between chickpea accession ICC 3996 (resistant to ascochyta blight, early flowering, and semi-erect plant growth habit) and C. reticulatum accession ILWC 184 (susceptible to ascochyta blight, ii late flowering, and prostrate plant growth habit) was used for constructing a genetic linkage map. F2 plants were cloned through stem cuttings taken at pre-flowering stage, treated with plant growth regulator powder (0.5 mg/g indole butyric acid (IBA) and 0.5 mg/g naphthalene acetic acid (NAA)) and grown in a sand + potting mix substrate. Clones were screened for ascochyta blight resistance in controlled environment conditions using a 19 scale. Three quantitative trait loci (QTLs) were found for ascochyta blight resistance in this population. Two linked QTLs, located on linkage group (LG) 4, explained 21.1% and 4.9% of the phenotypic variation. The other QTL, located on LG3, explained 22.7% of the phenotypic variation for ascochyta blight resistance. These QTLs explained almost 49% of the variation for ascochyta blight resistance. LG3 had two major QTLs for days to flowering (explaining 90.2% of phenotypic variation) and a major single QTL for plant growth habit (explaining 95.2% of phenotypic variation). There was a negative correlation between ascochyta blight resistance and days to flowering, and a positive correlation between days to flowering and plant growth habit. The flanking markers for ascochyta blight resistance or other morphological characters can be used in marker-assisted selections to facilitate breeding programs.
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Baron, Étienne. "Génomique écologique de la réponse à la compétition chez Arabidopsis thaliana." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10206/document.
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La compétition est considérée comme un facteur majeur responsable de la structure, de la diversité et de la dynamique des communautés végétales. Cependant, la génétique sous-jacente à cette dynamique éco-évolutive est encore peu connue. Notamment, à l’échelle d’une population, la variation génétique naturelle de la réponse à différentes conditions de compétition, l’identité des traits phénotypiques sous sélection génotypique et des bases génétiques impliquées dans la réponse à la compétition sont mal compris. Par une approche de génomique écologique ciblant l’espèce modèle Arabidopsis thaliana, l’objectif principal de cette thèse est de caractériser la génétique associée à la capacité compétitrice à une échelle locale selon une complexité d’interactions avec des espèces compétitrices progressive. En me focalisant d’abord sur la compétition monospécifique, j’ai montré que l’identité du compétiteur et le décalage de sa germination permettaient un maintien de diversité génétique et fonctionnelle au sein de la population-cible. Par une approche de Genome Wide Association (GWA) mapping, j’ai identifié différents QTLs de réponse à la compétition selon les conditions de compétition monospécifique. Puis, j’ai démontré que le contexte d’interactions plurispécifiques modifiait la réponse à la compétition d’une population locale. De plus, j’ai montré que la réponse à la compétition d’une population locale pouvait évoluer en huit générations, en lien avec des changements de composition spécifique au sein de la communauté. Enfin, j’ai démontré que la dynamique adaptative d’A. thaliana pouvait être fortement influencée par l’intensité de la compétition en conditions naturellesCompetition is considered as a major factor responsible for plant communities structure, diversity and dynamics. However, the genetics underlying this local eco-evolutionary dynamics remains poorly understood. Notably, at the population scale, the natural genetic variation of response to different competition conditions, the identity of phenotypic traits under genotypic selection and of genetic basis implied in the response to competition still need to be addressed. By an ecological genomics approach using the model species Arabidopsis thaliana, the main goal of this thesis is to characterize the genetics related to the competitive ability at a local scale, according to an increasing complexity of interactions between the competitor species. First, by focusing on monospecific competition, I showed that both the competitor identity and the lag of competitor germination time promote the maintenance of the genetic and functional diversities within the target population. Based on an approach of Genome Wide Association (GWA) mapping, I detected QTLs of response to competition that were strongly dependent on the conditions of monospecific competition. Second, in the context of multispecific interactions, I demonstrated that the response of a local population to competition was highly specific to the surrounding communities considered. In addition, based on a resurrection approach, I showed that the response of a local population to competition could evolve in less than eight generations, likely in relationship to community shifts. Third, I demonstrated that the adaptive dynamic of A. thaliana was highly influenced by the competition intensity in natural conditions
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Mohamad, Roba. "Adaptation des bactéries symbiotiques de légumineuses métallicoles : effets des métaux lourds et de la plante hôte sur la composition des populations de rhizobia symbiotiques d’Anthyllis vulneraria et de Lotus corniculatus." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT153/document.
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Deux légumineuses (Anthyllis vulneraria et Lotus corniculatus) adaptées aux métaux lourds constituent un matériel d’intérêt pour la phytostabilisation de sites miniers. Leur fonction de fixatrices biologiques d’azote grâce à leur symbiose avec des bactéries symbiotiques permet l’établissement efficace d’une couverture végétale durable limitant la dispersion des métaux dans l’environnement. Nos objectifs ont été d’étudier les effets des métaux lourds et de la plante hôte sur les populations symbiotiques naturellement associées à ces légumineuses en analysant (i) les populations symbiotiques associées à A. vulneraria sur 8 sites contaminés ou non (ii) les populations de rhizobia associées à L. corniculatus qui ont été comparées à celles d’Anthyllis. La distribution des souches de Mesorhizobium isolées de nodosités d’A. vulneraria et provenant de plusieurs sites contaminés ou non dépend des fortes teneurs en métaux lourds des sols qui sélectionnent fortement les souches symbiotiques résistantes et influencent leur composition taxonomique. Les souches appartenant à l’espèce M. metallidurans ont été retrouvées seulement dans les sites fortement contaminés. Deux nouvelles espèces potentielles et résistantes aux métaux semblent exister chacune sur un site minier distinct. L’une d’elle est proche de M. ciceri et de M. loti et tous ses membres présentent la particularité de ne pas posséder de gène cadA, un gène impliqué dans la tolérance aux métaux chez M. metallidurans. Par contre, les sites non contaminés révèlent une diversité taxonomique différente avec la présence de nouvelles espèces de Mesorhizobium sensibles aux métaux lourds. Quatre de ces nouvelles espèces ont été définies. A. vulneraria et L. corniculatus partagent la même diversité taxonomique dans les sites contaminés testés. Par contre, les propriétés symbiotiques des souches varient selon la plante hôte utilisée pour le piégeage. Les souches appartiennent soit au symbiovar (sv.) anthyllidis soit au sv. loti selon le site géographique d’origine et ceci indépendamment des teneurs en métaux lourds dans le sol. A. vulneraria s’associe avec les souches possédant les sv. anthyllidis ou sv. loti. En revanche, L. corniculatus ne s’associe qu’avec des souches du sv. loti. Dans tous les sols qu’ils soient contaminés ou non, A. vulneraria nodule préférentiellement avec le sv. anthyllidis. En conclusion, A. vulneraria et L. corniculatus établissent des symbioses avec les mêmes espèces de Mesorhizobium et s’associent préférentiellement avec un sv. Les taxons retrouvés dépendent fortement des sites d’isolement, ce qui pourrait traduire des adaptations particulières aux conditions environnementales. L’utilisation des ressources biologiques locales est une stratégie que nous recommandons pour la végétalisation d’anciens sites miniersTwo legumes (Anthyllis vulneraria and Lotus corniculatus) adapted to heavy metals form an interesting material for phytostabilisation strategy in mining sites. As biological nitrogen fixators, these legumes associated with compatible symbiotic bacteria provide an efficient establishment of a sustainable cover vegetation limiting metal dispersion in the environment. Our objectives were to study the effects of heavy metals and the host plant on symbiotic populations naturally associated with these legumes by analyzing (i) symbiotic populations associated with A. vulneraria on 8 contaminated and uncontaminated sites (ii) rhizobial populations associated with L. corniculatus that were compared with those of Anthyllis. The distribution of mesorhizobial strains isolated from A. vulneraria root-nodules from several contaminated and uncontaminated sites depends on high levels of heavy metals in soils by selecting highly resistant strains and impacting the taxonomic composition. Strains belonging to M. metallidurans were only found in highly contaminated sites. Two new potential metal-tolerant species were detected in two distinct mines. One of them was closely related to M. ciceri and M. loti and its members had the feature of not -possessing the cadA gene, a gene involved in metal-tolerance among M. metallidurans strains. By contrast, uncontaminated sites revealed a different taxonomic diversity with new species sensitive to heavy metals. Four of these new species were defined. A. vulneraria and L. corniculatus share the same taxonomic diversity in the contaminated sites tested. By contrast, symbiotic properties of the strains vary depending on the host plant used for trapping. Strains belong either to symbiovar (sv.) anthyllidis or to sv. loti according to geographic origins and independently of heavy metal levels in soils. A. vulneraria associated with strains of sv. anthyllidis or sv. loti. In contrast, L. corniculatus only associated with strains of sv. loti. In contaminated or uncontaminated soils, A. vulneraria was preferentially nodulated by sv. anthyllidis. In conclusion, A. vulneraria and L. corniculatus established symbiotic relationships with the same taxonomic groups of Mesorhizobium but associated with different symbiovars. The finding of taxonomic groups strongly depends on geographical sites, suggesting special adaptations to environmental conditions. Use of local biological resources is the strategy we recommend for revegetation of old mines
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Duriez, Pauline. "Caractérisation génétique, moléculaire et physiologique du locus Or7 de résistance à Orobanche cumana chez le tournesol." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30006.
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Orobanche cumana est une plante parasite obligatoire qui infecte spécifiquement le tournesol, entrainant des pertes de rendement. En combinant des études génétiques et génomiques dans une approche de clonage positionnel, le gène de résistance à l'orobanche du tournesol HaOr7 a été cartographié dans une région de 55 kb du chromosome 7, contenant un gène unique. Le gène HaOr7 code pour un récepteur membranaire de type LRR kinase, montrant de l'homologie avec le gène Xa21 qui confère la résistance à la bactérie Xanthomonas oryzae pv. Oryzae chez le riz. Toutes les lignées résistantes comportaient un allèle du gène codant pour la protéine HAOR7 complète tandis que les allèles du gène de toutes les lignées sensibles codaient pour une protéine tronquée, sans le domaine kinase, ni le domaine transmembranaire. Nous avons montré que HaOr7 confère une résistance en empêchant O. cumana de se connecter au système vasculaire des racines de tournesol, dans une relation gène-pour-gène. Nos résultats illustrent que les plantes utilisent des mécanismes de résistance contre les plantes parasites similaires à ceux qu'elles utilisent pour lutter contre les microorganismes pathogènes. HaOr7 est le premier gène de résistance à O. cumana à avoir été caractérisé chez le tournesol, ouvrant de nouvelles voies pour une résistance plus durable à O. cumana et aux plantes parasitesOrobanche cumana (sunflower broomrape) is an obligate parasitic plant that specifically infects sunflower roots, causing yield losses. By combining genomics and genetics in a map-based cloning strategy, we located the HaOr7 resistance gene to O. cumana in a 55 kb genomic region on chromosome 7 containing a single gene. The HaOr7 gene encodes a receptor-like LRR kinase protein sharing similarity with Xa21 in rice, conferring resistance to the bacteria Xanthomonas oryzae pv. oryzae. The complete HAOR7 protein was found in all resistant lines, while susceptible lines all encoded a truncated protein lacking the transmembrane and the kinase domains. We showed that HaOr7 confers resistance by preventing the connection of O. cumana to the vascular system of the sunflower roots in a gene-for-gene relationship. Our results illustrate how plants can use similar mechanisms for the resistance to parasitic plants as the ones for resistance to microorganisms. HaOr7 is the first resistance gene to O. cumana to be cloned in sunflower, opening new avenues for a more sustainable resistance to sunflower broomrape and to parasitic plants in crops
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Sakrison, Rodney G. "Summer water use in compact communities : the effect of small lots and growth management plans on single-family water use in King County, Washington /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/10797.
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Mukhaimar, Maisara. "Sources naturelles de la résistance contre les nématodes à galles Meloidogyne javanica chez la plante modèle Arabidopsis thaliana." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112033/document.
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Les nématodes phytoparasites constituent une menace réelle pour la production alimentaire mondiale. Ils sont responsables de 14% des pertes de rendement de la production alimentaire globale, ce pourcentage est l’équivalent de 100 milliards de dollar américain par an. La lutte contre ces phytoparasites est devenue un défit majeur, notamment après l'interdiction de l'utilisation du nématicide le plus efficace, en raison de ses effets nocifs sur l’environnement. Par conséquent, des nouvelles sources pour la gestion des nématodes phytoparasites sont nécessaires et urgentes. Ce travail vise à déterminer si la plante modèle Arabidopsis thaliana pourrait servir comme une source naturelle de gènes de la résistance aux nématodes phytoparasites. Parmi des accessions d’Arabidopsis, on a trouvé une variation génétique naturelle de la résistance contre les nématodes à galles Meloidogyne javanica, on a également identifié plusieurs QTL de résistance aux nématodes, et finalement, on a réalisé une cartographie fine d’un des QTL détectésPlant-parasitic nematodes are a serious threat for global food production. They are responsible for 14% of global yield loss, equivalent to an economic value of more than 100 billion US$ per year. Pest management is challenging, in particular since the most efficient nematicide has been banned due to its devastating effect on the environment. Hence, novel sources for nematode management are urgently required. This work investigates whether the model plant Arabidopsis thaliana could serve as a natural source for resistance genes against plant-parasitic nematodes. It finds natural genetic variation among Arabidopsis accessions for resistance against the root-knot nematode Meloidogyne javanica, identifies several QTL for nematode resistance, and fine-maps one of these resistance QTL
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Tatsumi, Jason. "On the Analysis and Design of Disturbance Rejecter." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1386946867.
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Billotte, Norbert. "Recherche et étude des locus contrôlant les caractères à déterminisme génétique complexe (QTL) du palmier a huile (Elaeis guineensis Jacq. ), par cartographie génétique multiparentale." École nationale supérieure agronomique (Montpellier), 2004. http://www.theses.fr/2004ENSA0023.
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Une recherche multiparentale de QTL agronomiques a été réalisée étape par étape chez le palmier à huile (E. Guineensis Jacq. ), de la production des marqueurs moléculaires à l’identification des QTL, en vue d’une amélioration génétique de la plante. Un nombre total de 390 marqueurs microsatellite (SSR) a été développé chez le palmier à huile. Le polymorphisme SSR a été caractérisé sur l’espèce E. Guineensis, mais également chez l’espèce proche E. Oleifera vers laquelle une transférabilité optimale des marqueurs a été observée, ainsi que chez 16 autres espèces de Palmae dont le cocotier (C. Nucifera). Vingt-six caractères phénotypiques quantitatifs ont été étudiés au travers d’un plan de croisement de type factoriel complet 2 x 2 impliquant 4 parents issus de 3 fonds génétiques Deli, La Mé et Yangambi. Une carte génétique de référence a été élaborée sur un croisement LM2T x DA10D du plan factoriel, à l’aide de 944 locus (255 SSR, 688 AFLP, locus Sh) distribués sur 16 groupes de liaison correspondant aux 16 paires de chromosomes de la plante. Cette carte de 1735 cM a permis d’échantillonner 253 locus SSR à l’aide desquels une carte génétique consensus du plan factoriel a été construite. En outre, 2 marqueurs AFLP ont été identifiés à 7 cM et à 11 cM du gène Sh gouvernant le type variétal du fruit chez le palmier à huile, par une analyse de ségrégation en mélange et par cartographie génétique. Un ensemble de 71 QTL de caractères végétatifs et de production ont été identifiés sur le plan factoriel 2 x 2, par une analyse CIM à l’aide de 3 types de modèle linéaire additif de recherche de QTL, grâce à un logiciel pilote MCQTL Outbred mis au point par l’INRA (France) : modèles d’analyse croisement par croisement, multiparental déconnecté ou multiparental connecté. Une validation des QTL identifiés et une intégration de l’approche multiparentale sont proposées dans le cadre d’un schéma général de sélection assistée par marqueurs du palmier à huile dans le contexte du genre ElaeisThe goal of this work was to search and to study the loci of characters under complex genetic control (QTL) in the oil palm (Elaeis guineensis Jacq. ), by multi-parent genetic mapping. Results are given step by step from the production of molecular markers to the identification of agronomic QTL, in view to marker-assisted breeding of oil palm. A total number of 390 microsatellite markers (SSR) were developed in the E. Guineensis species. The SSR polymorphism was characterised in the E. Guineensis and in the closely related species E. Oleifera, in which an optimal utility of the SSR markers was observed, as well as on a subset of 16 other palm species. Twenty-six phenotypic quantitative characters were studied using a 2 x 2 complete factorial mating design involving 4 heterozygous parents issued from 3 genetic backgrounds Deli, La Mé and Yangambi. A reference linkage map was constructed in the control cross LM2T x DA10D of the factorial design, using 944 locus (255 SR, 688 AFLP, locus Sh) distributed on 16 linkage groups representing the 16 chromosome pairs of the oil palm. This linkage map of 1735 cM allowed to sample 253 SSR loci distributed along the genome and which were used to construct a consensus map of the factorial design. Also, two markers were located at 7 cM and at 11 cM on each side of the Sh locus controlling the variety type of the fruit in oil palm, using bulk segregant analysis and linkage mapping methods. A set of 71 QTL of vegetative and production characters were identified thanks to the factorial design, using a CIM method with 3 types of additive linear models for the QTL search, under a new MCQTL Outbred software perfected by INRA (France): cross by cross model, disconnected multi-parent model and connected multi-parent model. A validation of the identified QTL and an integration of the multi-parent approach are proposed in the frame of a general marker-assisted breeding scheme of oil palm within the context of its Elaeis genus
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Arnal, Gregory. "Discovery and characterization of biomass-degrading enzymes and enzyme sytems in termite gut microbial ecosystems." Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0040.
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Cette thèse a été réalisée dans le cadre du projet Futurol, un projet national français qui vise à produire du bioéthanol à partir de biomasses végétales telles que le bois ou la paille de céréale. Pour cela, la biomasse doit être prétraitée puis digérée enzymatiquement pour libérer des sucres fermentescibles. Ma contribution dans ce projet a été de découvrir des enzymes originales pour l’hydrolyse de l’hémicellulose, un hétéropolysaccharide, constituant majeur de la paroi cellulaire des cellules végétales. Afin de rechercher de nouveaux biocatalyseurs, une approche de métagénomique a été adoptée afin de sonder les intestins de deux espèces de termites : N. corniger, un termite xylophage, et T. hispaniolae un termite humivore / xylophage. 30 000 clones métagénomiques ont été criblés sur 10 substrats cellulosiques et hémicellulosique, et 660 hits ont été obtenus. La comparaison phénotypique a montré une différence claire entre ces deux banques, probablement liée au régime alimentaire des deux espèces de termite. Le séquençage de 45 clones N. corniger a révélé 120 séquences codant pour des enzymes originales, de nombreuses étant multimodulaires et / ou organisées en cluster de gènes. Dans un second temps, une approche à haut-débit a été adoptée pour le clonage, l’expression et la caractérisation légère de 104 enzymes entières ou formes tronquées. 45 protéines recombinantes ont été produites de manière soluble, et les activités de 19 enzymes et de 12 modules enzymatiques ont été montrées, permettant la mise au point d’une boite à outil hemicellulolytique. Dans certains cas, l’activité de modules classés « Inconnus » a pu être déterminée. Cette approche a été particulièrement pertinente dans le cas de Pm69, une enzyme multimodulaire GH3-UNK-CBM48-CE1 montrant les 3 activités glucosidase, xylosidase and estérase. Cette étude a permis de poser les bases d’un brevet sur cette enzyme. D’un autre côté, les enzymes ayant montré une activité xylanase ou féruloyle-estérase se sont révélées complémentaires d’un cocktail cellulolytique durant la dégradation de paille de blé prétraitée. Enfin, dans une troisième partie, nous avons étudié un fragment d’ADN provenant la banque P. militaris, codant pour 19 ORFs et appartenant à une espèce du genre Bacteroides. La caractérisation biochimique d’Abn43A, Abn43B, Abf51A et Abf51B-trunc a montré que ces 4 enzymes portent des actions complémentaires sur l’hydrolyse de l’arabinane, et qu’elles peuvent agir de manière synergique pour la dégradation de ce polymère pectique. Enfin, l’étude détaillée des 19 ORFs codées sur ce fragment d’ADN nous a permis de proposer un schéma global de détection, d’hydrolyse et de métabolisation de l’arabinane par cette espèce du genre BacteroidesThis thesis was performed in the context of the Futurol project, a French national project that aims at producing bioethanol from plant biomass such as wood and cereal straw. To reach that goal, the biomass must be pretreated, and enzymatically degraded to release fermentable simple sugar. My implication in that project was to discover original enzymes that can hydrolyze the hemicellulose, a major heteropolysaccharide found in plant cell wall.To mine for new biocatalysts, the gut microbial communities of two species of termite were investigated by a metagenomic approach : Nasutitermes corniger, a wood-feeder termite, and Termes hispaniolae supposed to be a soil-wood feeder. 30 000 metagenomic clones were screened on an array of 10 cellulosic and hemicellulosic substrates and 660 hits were obtained. Phenotypic comparison showed clear differences between both environments, probably related to the diet of the termite. The sequence of 45 N. corniger metagenomic inserts revealed 120 original sequences encoding for putative enzymes of interest. Original sequences encoding for multimodular enzymes were revealed and many ORFs were organized in clusters, suggesting that these enzymes are encoded on Polysaccharides Utilization Locus. In a second part, a high-throughput approach was used for the cloning, the expression and the slight characterization of 104 full-size and truncated enzymes. Forty five recombinant proteins were produced soluble, and their investigation revealed the activity of 19 enzymes and of 12 enzymatic modules, representing a hemicellulolytic tool-box for endo- and exo-type activities. In some cases, the implication of “Unkown” domains in the activity of multimodular enzymes was demonstrated. This approach was particularly efficient for the study of the GH3-UNKCBM48-CE1 Pm69, and this study triggered the patent process for this multiactive glucosidase, xylosidase and esterase. The xylanases and the feruloyl esterases were shown to be particularly efficient to supplement cellulolytic cocktails on pretreated wheat straw. In a third part, we investigated a DNA fragment belonging to a species of the genus Bacteroides and that encoded 19 ORFs. The biochemical characterization of Abn43A, Abn43B, Abf51A and Abf51B-trunc showed that these four enzymes harbored complementary actions for the hydrolysis of the arabinan, and that they can act synergistically for the hydrolysis of this pectic polymer. We also revealed that Abn43B had an original mode of action that we classified as exo-arabinanase. Finally, the in-depth study of the 19 ORFs allowed us to propose the entire scheme for arabinan detection, hydrolysis and utilization by the Bacteroides species carrying this DNA sequence
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Ortega, Maria Andrea. "Identification of Molecular Markers Associated with the Rps8 locus in Soybean and Evaluation of Microsporogenesis in Rps8/rps8 Heterozygous Lines." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259772038.
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Alfares, Walid. "Analyses génétiques et moléculaires du locus SKr impliqué dans l'aptitude du blé (Triticum aestivum L. ) au croisement avec le seigle (Secale cereale L. )." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00724743.
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La plupart de variétés élites de blé tendre ne peuvent pas être croisées avec des espèces apparentées ce qui restreint considérablement la base génétique qui peut être utilisée pour l'introgression de nouveaux allèles dans les programmes de sélection. L'inhibition de l'hybridation entre le blé et les espèces apparentées (e.g. seigle, orge) est génétiquement contrôlée. Un certain nombre de QTLs ont été identifiés à ce jour, y compris les gènes Kr1 sur le chromosome 5BL et SKr, un QTL majeur identifié au laboratoire en 1998 sur le bras court du chromosome 5B, tous deux impliqués dans l'inhibition du croisement entre le blé tendre et le seigle. Dans cette étude, nous avons utilisé une population recombinante SSD provenant d'un croisement entre la variété Courtot non croisable et la lignée MP98 croisable pour caractériser l'effet majeur dominant de SKr. Le gène a ensuite été cartographié génétiquement sur la partie distale du chromosome 5BS à proximité du locus GSP (Grain Softness Protein) dont l'homéologue sur le chromosome 5D est impliqué dans la dureté du grain (locus Ha). Les relations de colinéarité avec l'orge et le riz ont été utilisées pour saturer la région de SKr par de nouveaux marqueurs et établir des relations orthologues avec une région de 54 kb sur le chromosome 12L de riz. Au total, 6 marqueurs moléculaires ont été cartographiés dans un intervalle génétique de 0,3 cM, et 400 kb de contigs physiques de BAC ont été établis des deux cotés du gène afin de jeter les bases du clonage positionnel de SKr. De nouvelles populations de grands effectifs ont été développées pour la localisation précise du gène SKr sur les cartes génétiques et physiques. 223 individus d'une population HIF (SSD254.14) ont été testés pour leur aptitude au croisement avec le seigle et génotypés avec les marqueurs proches du gène pour confirmer les données obtenues dans la population de départ. Les résultats montrent que SKr est localisé dans une région hautement recombinante et que les relations entre distances génétiques et distances physiques sont favorables aux dernières étapes de clonage positionnel du gène. Enfin, deux marqueurs SSR complètement liés au gène SKr ont été utilisés pour évaluer une collection de descendances de blé aptes au croisement avec le seigle originaires d'un programme de sélection de triticale primaire. Les résultats confirment l'effet majeur de SKr sur l'aptitude au croisement et l'utilité des deux marqueurs pour introgresser l'aptitude au croisement interspécifique dans des variétés élites de blé tendre.
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Silva, Rosangela Aparecida da. "Estudo da fauna fitonematológica na Mata Atlântica do estado de São Paulo e na Floresta Amazônica do estado do Mato Grosso." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11135/tde-07102008-080545/.
Full textAbstract:
Realizou-se estudo da fauna de fitonematóides em dois municípios do estado de São Paulo (Pariquera-Açu e Cananéia) sob domínio da Mata Atlântica e dois do estado do Mato Grosso (Nova Maringá e Guarantã do Norte) sob domínio da Floresta Amazônica, com o objetivo de conhecer a diversidade de fitonematóides desses biomas e avaliar o efeito do uso agrícola do solo sobre a comunidade de fitonematóides. Para tanto, foram efetuadas amostragens em áreas de vegetação primária e em áreas próximas cultivadas. Para cada amostra, foram extraídos os nematóides de 200 cm³ de solo e em 10 gramas de raízes pela técnica de peneiramento combinada com flutuação em centrífuga com solução de sacarose. Em seguida, os espécimes foram mortos pelo calor e fixados em formalina. Os nematóides foram posteriormente quantificados, para determinação da abundância de cada táxon, sendo as identificações taxonômicas realizadas com base em características morfológicas e morfométricas. Os dados foram analisados com base na abundância, freqüência e índices de similaridade (Jaccard e Bray e Curtis). Assinalaram-se 34 gêneros e as identificações específicas foram efetuadas para 22 táxons. Para a espécie Aorolaimus banoae foram apresentadas novas características morfológicas e morfométricas. Observou-se que, com a retirada da vegetação primária e a implantação dos cultivos de plantas perenes ou anuais, houve intenso processo de redução da diversidade de fitonematóides e da introdução de novos táxons, o que resultou em baixa similaridade entre os locais de vegetação primária e aqueles cultivados, demostrando-se elevada influência da atividade agrícola sobre a comunidade de fitonematóides.A study about plant parasitic nematode fauna was conducted in two municipalities from São Paulo State (Pariquera-Açu and Cananéia in the Atlantic Forest) and two from Mato Grosso State (Nova Maringá and Guarantã do Norte in the Amazon Forest), Brazil. The aims of this study were to evaluate the diversity of plant-parasitic nematode fauna in locations of primary and to evaluate the effect of agricultural land use on the plant parasitic nematode communities. Nematodes were extracted from 200 cm³ of soil and 10 grams of roots by a sieving and sugar flotations technique and fixed with formalin. Nematodes were counted for determination of abundances of each taxon and the taxonomic identification was based on morphological and morphometric features. The following variables were obtained: abundance, frequency and similarity indexes (Jaccard and Bray e Curtis). A total number of 34 genera were recorded and 22 taxons were identified at species level. Concerning Aorolaimus banoae species, new morphological and morphometric features were presented. It was observed that, after removal of primary vegetation and implantation of perennial or annual crops, occurred a conspicuous reduction of plant parasitic nematode diversity, associated with introduction of exotic species, resulting in low similarity between location of primary vegetation and the cultivated ones. The results demonstrated that the agricultural practices affect strongly the plant parasitic nematode communities.