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Zanewich, Karen P., and University of Lethbridge Faculty of Arts and Science. "Vernalization and gibberellin physiology of winter canola." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1993, 1993. http://hdl.handle.net/10133/52.
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Winter canola (Brassica napus cv. Crystal) requires vernalization, exposure to chilling, to induce bolting and flowering. Since gibberellins (GAs) have been implicated in the regulation of stem elongation and reproductive development in numerous plants, the role of GAs in events induced by vernalization was investigated. Three classical approaches for studying GA physiology were taken. Plant growth regulators were applied and showed that: (i) GA application induced stem elongation but not flowering in nonvernalized plants and (ii) plant growth retardants that block GA biosynthesis prevented elongation and flowering in vernalized plants. Endogenous GAs were extracted from vernalized and nonvernalized shoot tips, chromatographically purified and quantified by gas chromatography-selected ion monitoring. GA1,3,8,19 and 20 concentrations were higher in the vernalized shoots following vernalization. Feeds of [3H]GA20 to vernalized and nonvernalized plants demonstrated higher rates of [3H]GA1 formation after vernalization, suggesting increased metabolism to the biologically active form. Collectively, these studies indicate a regulatory role of GAs in the control of stem elongation in winter canola, but the role of GAs in flowering was less clear. Vernalization apparently induces stem elongation by increasing GA synthesis and particularly the biosynthesis of GA1.xii, 138 leaves : ill., ports. ; 28 cm.
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Geraldo, Nuno D. C. "Molecular changes underlying the early stages of vernalization." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433587.
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Murphy, Lee Anne. "Vernalization response in spring oilseed rape, Brassica napus L." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23642.pdf.
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Strange, Amy. "Natural Variation in the Vernalization Response of Arabidopsis thaliana." Thesis, University of East Anglia, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502370.
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Within Arabidopsis thaliana there is extensive natural variation in the timing of flowering. This thesis focuses on the variation in vernalization response, manifested as a requirement for different lengths of cold in order to fully accelerate flowering. During vernalization, the gene encoding the floral repressor FLC is silenced and this is maintained during subsequent development by a Polycomb-mediated chromatin silencing mechanism. Three accessions from Sweden (Lov-I, Ull-2-5 and Var-2-6) require extended vernalization due to a slower accumulation ofthe chromatin silencing during the cold. In this study a QTL analysis mapped the variation in vernalization response to chromosomes 1,4 and 5. Further fine mapping identified FLC as one ofthe loci underlying the QTL and polymorphisms in FLC were located in putative regulatory rather than protein-coding regions. Allelic variation in FLC was found to be directly responsible for variation in the stability ofFLC repression after short lengths of vernalization. Work is ongoing to map the nucleotide polymorphisms which are directly responsible for the phenotypic variation. The vernalization response of two accessions from America (Kno-I8 and RRS-IO) was also investigated. They express FLC at extremely low levels, but are late flowering. Vernalization response QTL in these accessions again mapped to chromosomes 1,4 and 5. Low FLC expression was associated with a transposable element insertion in intron 1 ofFLC. Cloning of this transposon into a wild-type FLC allele showed it inactivates function and demonstrated modifiers in the American accessions that result in their late flowering. Initial results are described from a European common garden experiment, addressing whether flowering time is an adaptive trait. It was found that the Swedish accessions described above have low fitness in non-vernalizing conditions.
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Williams, C. A. "Relationships between leaf development, carbohydrates and vernalization in cauliflower." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383746.
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Barrett, Lynne. "The role of Arabidopsis VRN1 in mediating the vernalization response." Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423800.
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Mandel, Roger M. "Hormones, photoperiod and vernalization in the control of flowering in Brassica." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq20752.pdf.
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Duncan, Susan. "Predicting the impact of climate change on vernalization for Arabidopsis thaliana." Thesis, University of East Anglia, 2015. https://ueaeprints.uea.ac.uk/54405/.
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Winter annual Arabidopsis thaliana plants require a prolonged period of cold, known as vernalization, to ensure prompt floral transition occurs in spring. This thesis addresses the question of whether partial saturation of cold requirements might delay flowering under future climate scenarios. Laboratory experiments set up to parameterize a predictive model revealed a surprising optimal vernalizing temperature for the Swedish accession Lov-1. Field experiments in Northern Sweden support the theory that this optimum likely reflects adaptation to autumn, rather than winter temperatures. A chilling unit model incorporating empirically derived parameters forecast an overall increase in effective vernalizing days for A. thaliana in northern Sweden. This increase is the result of an overall reduction in sub-zero temperatures that are predicted for northerly latitudes by the end of the century. Reductions in the number of effective vernalizing days were predicted for England and Spain, however these are unlikely to counteract the forcing effects of increased spring temperatures at these locations. This thesis also presents a novel method that enables single RNA molecules to be visualized for the first time in plants. This method was used to determine cell-to-cell variation and subcellular distribution of key vernalization gene transcripts before, during and after cold exposure. These results provide a unique insight into how plants perceive and integrate longterm temperature cues at the cellular level In summary, this thesis predicts the potential impact of climate change on A. thaliana vernalization across its species’ range. It also dissects transcriptional mechanisms that underlie long-term temperature integration. Modulation of these mechanisms is likely to be key for survival of some wild species and for maximizing crop yields under future climate scenarios.
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McKeown, Meghan. "Evolution of Vernalization and Photoperiod-Regulated Genetic Networks in the Grass Subfamily Pooideae." ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/650.
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Flowering time is a carefully regulated trait that integrates cues from temperature and photoperiod to coordinate flowering at favorable times of the year. This dissertation aims to understand the evolution of genetic architecture that facilitated the transition of Pooideae, a subfamily of grass, from the tropics to the temperate northern hemisphere approximately 50 million years ago. Two traits hypothesized to have facilitated this evolutionary shift are the use of long-term low-temperature (vernalization) to ready plants for flowering, and long-day photoperiods to induce flowering. In chapter one I review literature on the regulation of grass flowering by vernalization and photoperiod, and in chapters two and three I determine the role of VERNALIZATION 1 (VRN1) and VRN2, known to confer vernalization responsiveness in core Pooideae crop species, in flowering time across Pooideae. In chapter four, I then test predictions of the hypothesis that the Brachypodium distachyon miR5200 ortholog in the ancestor of Pooideae was important for suppressing short day flowering through its negative regulation of flowering time integrator FLOWERING LOCUS T (FT)/VERNALIZATION3 (VRN3). In combination with other studies, my data demonstrate that VRN1-mediated vernalization responsiveness evolved early in the Pooideae, while VRN2-mediated vernalization responsiveness appears to have evolved much later in the diversification of Pooideae. Although miR5200 likely evolved early in the Pooideae, its transcriptional regulation by short day photoperiod appears derived within Brachypodium distachyon. This work answers important questions about the evolutionary origin of temperature- and photoperiod-mediated flowering in an economically important clade that contains crop species such as wheat (Triticum aestivum) and barley (Hordeum vulgare). Directions for future work on this topic are discussed in chapter 5.
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Genger, Ruth Kathleen, and Ruth Genger@csiro au. "Cytosine methylation, methyltransferases and flowering time in Arabidopsis thaliana." The Australian National University. Faculty of Science, 2000. http://thesis.anu.edu.au./public/adt-ANU20011127.115231.
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Environmental signals such as photoperiod and temperature provide plants with seasonal information, allowing them to time flowering to occur in favourable conditions. Most ecotypes of the model plant Arabidopsis thaliana flower earlier in long photoperiods and after prolonged exposure to cold (vernalization). The vernalized state is stable through mitosis, but is not transmitted to progeny, suggesting that the vernalization signal may be transmitted via a modification of DNA such as cytosine methylation. The role of methylation in the vernalization response is investigated in this thesis.
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Arabidopsis plants transformed with an antisense construct to the cytosine methyltransferase METI (AMT) showed significant decreases in methylation. AMT plants flowered significantly earlier than unvernalized wildtype plants, and the promotion of flowering correlated with the extent of demethylation. The flowering time of mutants with decreased DNA methylation (ddm1) was promoted only in growth conditions in which wildtype plants showed a vernalization response, suggesting that the early flowering response to demethylation operated specifically through the vernalization pathway.
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The AMT construct was crossed into two late flowering mutants that differed in vernalization responsiveness. Demethylation promoted flowering of the vernalization responsive mutant fca, but not of the fe mutant, which has only a slight vernalization response. This supports the hypothesis that demethylation is a step in the vernalization pathway.
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The role of gibberellic acid (GA) in the early flowering response to demethylation was investigated by observing the effect of the gai mutation, which disrupts the GA signal transduction pathway, on flowering time in plants with demethylated DNA. The presence of a single gai allele delayed flowering, suggesting that the early flowering response to demethylation requires a functional GA signal transduction pathway, and that demethylation increases GA levels or responses, directly or indirectly.
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In most transgenic lines, AMT-mediated demethylation did not fully substitute for vernalization. This indicates that part of the response is not affected by METI-mediated methylation, and may involve a second methyltransferase or a factor other than methylation. A second Arabidopsis methyltransferase, METIIa, was characterized and compared to METI. The two genes are very similar throughout the coding region, and share the location of their eleven introns, indicating that they diverged relatively recently. Both are transcribed in all tissues and at all developmental stages assayed, but the level of expression of METI is significantly higher than that of METIIa. The possible functions of METI, METIIa, and other Arabidopsis cytosine methyltransferase genes recently identified are discussed.
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McCulloch, Hayley Louise. "Genetic basis for natural variation in flowering time in local populations of Arabidopsis thaliana." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/9501.
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Factors affecting flowering time have been extensively studied for decades. Greater understanding of flowering time has wider implications in agriculture and ecology as the trait is crucial to optimising reproductive success. It is best understood in the genetic model Arabidopsis thaliana (Arabidopsis), in which loss and gain of function mutations have identified several pathways that regulate flowering and its response to the environment. This has been complemented by studies of natural variation in flowering. Worldwide accessions of Arabidopsis have been used to identify additional flowering regulators and to examine the evolution of these genes and their potential involvement in adaptation to different environments. One of the most extensively studied pathways is responsible for accelerated flowering in response to an extended period of cold (vernalization). Several studies have attributed a substantial proportion of worldwide variation to the genes FRIGIDA (FRI) and FLOWERING LOCUS C (FLC), both of which are instrumental in conferring sensitivity to vernalization, though other genes have also been found. This study examines flowering time variation locally in populations of Arabidopsis from in and around Edinburgh. It identifies substantial, genetically determined variation in flowering time and in sensitivity to photoperiod and vernalization between local accessions. Variation in FRI and FLC sequences and in their levels of expression were detected in local accessions, but these were able to explain little of the phenotypic variation observed. Hybrids between local accessions showing extreme differences in flowering time or responses to photoperiod and vernalization were therefore used to map genes underlying their differences as quantitative trait loci (QTL). This analysis identified a locus in chromosome 5 that could account for differences in vernalization sensitivity. This region includes the VERNALIZATION INSENSITIVE 3 (VIN3) gene. Sequence differences between VIN3 alleles and their expression in response to vernalization supported the potential involvement of this gene in local flowering time variation.
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Cockram, James. "Comparative genetic approaches to mapping the Vrn-H1 vernalization response gene in barley (Hordeum vulgare L.)." Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399792.
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Nardini, João Paulo Calore 1986. "Períodos de vernalização em bulbilhos semente livre de vírus de cultivares nobre de alho no cerrado brasileiro /." Botucatu, 2016. http://hdl.handle.net/11449/144466.
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Orientador: Marcelo Agenor PavanBanca: Filipe Pereira Giardini Bonfim
Banca: Julio Massaharu Marubayashi
Resumo: O alho (Allium sativum L.) não possui semente verdadeiramente botânica, sendo assim, sua única via de propagação se dá vegetativamente, fato este que implica regularmente numa infecção viral mista, se tornando uma das principais causas da redução de produtividade. Alguns produtores já possuem acesso a semente de alho 'Livre de Vírus', no entanto, ainda utilizam de vernalização antiquada, preconizada pela pesquisa para alho semente infectada por vírus (material comum para maioria dos produtores nacionais), e quando utilizada pelos produtores em alho-semente 'Livre de Vírus', vem acarretando problemas principalmente para os produtores do cerrado, onde o plantio é antecipado. Neste estudo foi avaliado o efeito da temperatura de vernalização a 4ºC combinada por diferentes períodos (30, 40, 50 e 60 dias) em bulbilho-semente livre de vírus. O experimento foi conduzido de acordo coma a safra da cultura na região (março à outubro), em fazendas localizadas nos municípios de Santa Juliana (MG) e Campo Alegre de Goiás (GO): regiões de cerrado que se destacam atualmente pela produção de alho nobre no Brasil. Foram avaliadas três das principais cultivares existentes no mercado, sendo elas: Caçador, Quitéria e Ito. As maiores produtividades de bulbos comerciais para as cultivares Caçador em Campo Alegre de Goiás (GO) 2014 e Santa Juliana (MG) 2014 foram nos tratamentos de 30 e 40 dias de vernalização, respectivamente, conciliando produtividades de 11,3 t.ha-¹ e 12,4 t.ha-¹, com boa qualida... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract : Garlic (Allium sativum L.) does not really have truly botanic seeds; therefore, its only way of propagation is vegetatively, which regularly implies in a mixed viral infection that becomes the major cause of reduced productivity. Some producers already have access to garlic seed 'Virus Free', however, still use old-fashioned vernalization, recommended by the search for seed infected garlic virus (common material for most domestic producers), and when used by producers in garlic-seed 'Virus Free', has been causing problems especially for the cerrado producers, where planting is anticipated. This study evaluated the effect of vernalization temperature of 4 ° C combined for different periods (30, 40, 50 and 60 days) in virus free bulbil seed. The experiment was conducted in accordance eat the harvest of culture in the region (march to october), in farms located in the cities of Santa Juliana (MG) and Campo Alegre de Goiás (GO): cerrado regions which are currently out for garlic production noble in Brazil. Were evaluated three of the main existing cultivars on the market, which are: Caçador, Quiteria and Ito. The highest commercial bulbs for Caçador in Campo Alegre de Goiás (GO) 2014 and Santa Juliana (MG) in 2014 were the treatments of 30 and 40 days of vernalization, respectively, combining yields of 11.3 t ha-¹ and 12.4 t ha-¹, with good quality bulb. Quitéria in Campo Alegre de Goiás (GO) in 2014 achieved a better result with treatment of 51 days of vernalization, reaching productivity of 16.8 t ha-¹. 'Ito' 2015 Campo Alegre de Goiás (GO) and Santa Juliana (MG) ...
Mestre
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Hasan, Yaser [Verfasser]. "Genetic dissection and QTL based modeling of vernalization and curd development in cauliflower (Brassica oleracea var. botrytis) / Yaser Hasan." Hannover : Technische Informationsbibliothek (TIB), 2016. http://d-nb.info/1119905893/34.
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Han, Qingxiang. "Lineage isolation maintained by natural selection despite ongoing gene flow in Japanese wild radish." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225684.
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Doong, Tzyy-Jye. "Regulation of Gibberellin Metabolism by Environmental Factors in Arabidopsis Thaliana." Columbus, Ohio : Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1034085989.
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Thesis (Ph. D.)--Ohio State University, 2002.Title from first page of PDF file. Document formatted into pages; contains xi, 148 p.; also contains graphics (some col.). Includes abstract and vita. Advisor: James Metzger, Dept. of Horticulture and Crop Science. Includes bibliographical references (p. 132-148).
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Ntiamoah, Charles. "Effects of temperature, photoperiod, and vernalization on the growth, development, and predictions by the CERES-wheat model, for spring wheat cultivars." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ62662.pdf.
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Dessureault, Darlene. "Evaluation of the risks and profitability for early planting dates and bolt reducing strategies for Quebec celery production." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82223.
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The risks and profitability associated with four early planting dates, and three different types of bolting risk reduction strategies, were evaluated for Quebec celery production. The four planting dates studied were April 17 th, April 24th, May 1st and May 8 th. The impacts on yield if plants were harvested after eleven week, twelve, thirteen, and fourteen weeks in the field were investigated. The three risk reduction strategies considered were plants grown from planting until June 2nd with no row covers, under floating row covers of spunbonded polyester (Agryl P17, Plastitech) and under floating row covers made of clear, perforated polyethylene (Plastitech). The results suggest that the floating row covers can help plants reach the required market standards sooner that if no row covers were used from the planting date investigated until June 2nd. At the earliest two planting dates, the results suggest that row covers may significantly suppress bolting and allow greater yields at earlier harvest dates. The results also suggest that row covers may provide an advantage at later planting dates, as they may allow for the plants to reach marketable standards sooner. The results also suggest that there is a 50 percent chance of encountering bolting rate of 30 percent or higher if transplanting plants on April 17th. The row covers reduced the probability that plants will bolt to close to zero at for all four planting dates. The most profitable strategy was determined to be planting on April 17th, growing the plants under row covers made of spunbonded polyester (Agryl P17, Plastitech) from planting until June 2nd and then harvesting after the plants had been in the field for thirteen weeks.
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Cote, John Christopher. "The impact of predevernalization and plasticulture treatments on bolting of celery (Apium graveolens L.) grown in Quebec /." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33742.
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Vernalized celery seedlings (Apium graveolens L. var. Florida 683) were predevernalized under different temperature and light regimes prior to field transplanting. At least 89% of predevernalized plants bolted during both 1999 and 2000 suggesting that the predevernalization treatments were not effective in counteracting the vernalizing stimulus. Predevernalization treatments had no long-term effect on growth and development. Non-vernalized celery seedlings were transplanted on clear polyethylene mulch, thermo-selective polyethylene mulch or no mulch in combination with clear perforated polyethylene mini tunnel, single or double layer of agrotextile mini tunnel or no mini tunnel. Very few plants bolted in 1999. Mulch increased fresh weight and number of celery leaves compared with controls. Plants grown on clear polyethylene mulch had significantly higher mortality rates than other treatments. Agrotextile mini tunnels reduced bolting to 0% in 2000. Mini tunnels, especially a single layer of agrotextile, increased fresh weight, plant height and stem diameter in 2000.
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Ejaz, Mahwish [Verfasser]. "PHOTOPERIOD 1 (Ppd-H1) and VERNALIZATION 1 (HvVRN1) Interact to Control Reproductive Development under High Ambient Temperatures in Barley (Hordeum vulgare L.) / Mahwish Ejaz." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2019. http://d-nb.info/1178112691/34.
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Schwarting, Holly N. "Examining Hessian fly (Mayetiola destructor) management concepts and quantifying the physiological impact of hessian fly feeding on post-vernalization selected cultivars of winter wheat in Kansas." Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18151.
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Doctor of PhilosophyDepartment of Entomology
R. Jeff Whitworth
The Hessian fly, Mayetiola destructor (Say), has been a historically significant pest of wheat in Kansas. However, it has been 60+ years since research has been conducted examining the flies’ activity throughout the year. Results of pheromone trapping in 4 counties in Kansas shows that Hessian fly (HF) males are actively flying in the fall, at least 1 month after the historical fly-free dates. Therefore, the Hessian Fly-Free Date is no longer valid and should be referred to as the Best Pest Management Date. Using pheromones for fall and spring trapping also indicated that HF is more active throughout the spring than previously thought, with almost continuous fly emergence and numerous emergence peaks in both spring and fall. The use of resistant wheat cultivars has been adapted to protect seedling plants from HF larval feeding in the fall. However, it is unknown if these cultivars are still providing protection after winter vernalization. Greenhouse trials indicated that ‘Armour’, a cultivar considered intermediately resistant, remains resistant under infestation levels of 1 fly/tiller but significant seed weight losses occured under infestations of 3 flies/tiller. In the field, Armour did not provide protection post-vernalization, with plants containing similar numbers of flaxseeds (pupae) as the susceptible cultivar, ‘Fuller’, and having significant losses of culm height (cm), number of spikelets/spike, number of seeds/spike, and seed weight (grams) when infested. ‘Duster’, a cultivar considered highly resistant, appeared to provide resistance to HF larval feeding in both the greenhouse and the field, and even produced significantly heavier seeds when infested with 3 flies/tiller in the greenhouse. These results suggest that post-vernalization screening should be conducted on all HF resistant cultivars to determine if each continues to provide protection. Little information is available showing if and how HF larval feeding on more mature wheat (Feekes 7-10), post-vernalization, impact plants, aside from lodging. Greenhouse and field infestations of a susceptible cultivar, Fuller, showed that significant losses of culm height (cm), number of seeds/spikelet, and seed weight will result from as few as 1 larva /culm. Yield losses averaged 0.13g/spike (65 kg/ha) compared to non-infested plants.
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Nardini, João Paulo Calore [UNESP]. "Períodos de vernalização em bulbilhos semente livre de vírus de cultivares nobre de alho no cerrado brasileiro." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144466.
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O alho (Allium sativum L.) não possui semente verdadeiramente botânica, sendo assim, sua única via de propagação se dá vegetativamente, fato este que implica regularmente numa infecção viral mista, se tornando uma das principais causas da redução de produtividade. Alguns produtores já possuem acesso a semente de alho ‘Livre de Vírus’, no entanto, ainda utilizam de vernalização antiquada, preconizada pela pesquisa para alho semente infectada por vírus (material comum para maioria dos produtores nacionais), e quando utilizada pelos produtores em alho-semente ‘Livre de Vírus’, vem acarretando problemas principalmente para os produtores do cerrado, onde o plantio é antecipado. Neste estudo foi avaliado o efeito da temperatura de vernalização a 4ºC combinada por diferentes períodos (30, 40, 50 e 60 dias) em bulbilho-semente livre de vírus. O experimento foi conduzido de acordo coma a safra da cultura na região (março à outubro), em fazendas localizadas nos municípios de Santa Juliana (MG) e Campo Alegre de Goiás (GO): regiões de cerrado que se destacam atualmente pela produção de alho nobre no Brasil. Foram avaliadas três das principais cultivares existentes no mercado, sendo elas: Caçador, Quitéria e Ito. As maiores produtividades de bulbos comerciais para as cultivares Caçador em Campo Alegre de Goiás (GO) 2014 e Santa Juliana (MG) 2014 foram nos tratamentos de 30 e 40 dias de vernalização, respectivamente, conciliando produtividades de 11,3 t.ha-¹ e 12,4 t.ha-¹, com boa qualidade de bulbo. A cultivar Quitéria em Campo Alegre de Goiás (GO) 2014 alcançou melhor resultado com tratamento de 51 dias de vernalização, atingindo produtividade de 16,8 t.ha-¹. ‘Ito’ 2015 em Campo Alegre de Goiás (GO) e Santa Juliana (MG) atingiu produtividades interessantes do ponto de vista comercial aos 30 e 40 dias de vernalização, respectivamente, atingindo 16,7 e 17,1 t.ha-¹. Também foi avaliado que para bulbilhos livre de vírus ‘Caçador’, se demonstraram menos susceptíveis à formação de bulbos ‘charutos’ em baixos períodos de vernalização, do que bulbilhos convencionais. Em longos períodos de vernalizações, ‘Caçador’ livre de vírus é mais sensíveis ao aparecimento de brotações laterais do que o convencional. Verificou-se ainda que o efeito dos tratamentos de vernalização teve influência direta no IVD na semeadura, tempo de diferenciação (dias), número de folhas na diferenciação, ciclo da cultura (dias), incidência de bulbos charutos e brotações laterais em todas as cultivares avaliadas. Observou-se que do ponto de vista prático, que não é recomendável a utilização de extensos períodos de vernalização para produção de semente, já que esta possui notável relação com o estímulo à produção de bulbilhos com mais de uma gema.
Garlic (Allium sativum L.) does not really have truly botanic seeds; therefore, its only way of propagation is vegetatively, which regularly implies in a mixed viral infection that becomes the major cause of reduced productivity. Some producers already have access to garlic seed 'Virus Free', however, still use old-fashioned vernalization, recommended by the search for seed infected garlic virus (common material for most domestic producers), and when used by producers in garlic-seed 'Virus Free', has been causing problems especially for the cerrado producers, where planting is anticipated. This study evaluated the effect of vernalization temperature of 4 ° C combined for different periods (30, 40, 50 and 60 days) in virus free bulbil seed. The experiment was conducted in accordance eat the harvest of culture in the region (march to october), in farms located in the cities of Santa Juliana (MG) and Campo Alegre de Goiás (GO): cerrado regions which are currently out for garlic production noble in Brazil. Were evaluated three of the main existing cultivars on the market, which are: Caçador, Quiteria and Ito. The highest commercial bulbs for Caçador in Campo Alegre de Goiás (GO) 2014 and Santa Juliana (MG) in 2014 were the treatments of 30 and 40 days of vernalization, respectively, combining yields of 11.3 t ha-¹ and 12.4 t ha-¹, with good quality bulb. Quitéria in Campo Alegre de Goiás (GO) in 2014 achieved a better result with treatment of 51 days of vernalization, reaching productivity of 16.8 t ha-¹. 'Ito' 2015 Campo Alegre de Goiás (GO) and Santa Juliana (MG) reached interesting productivities commercial point of view at 30 and 40 days of vernalization, respectively, reaching 16.7 and 17.1 t ha-¹. It was also reported that for virus free bulbils of "Caçador", have proved less susceptible to the formation of bulbs 'cigar' in low periods of vernalization than conventional bulbils. Over long periods of vernalizações 'Caçador ' virus free is more sensitive to the onset of side shoots than conventional. It was also found that the effect of vernalization had a direct influence on the IVD during sowing, differentiation time (days) number of leafs in the differentiation, culture cycle (days), the incidence of ‘cigars’ bulbs and side shoots in all cultivars evaluated. It was observed that from a practical point of view, it is not recommendable to use long periods of vernalization for seed production, since it has remarkable relationship to stimulate production of bulbils over a gem.
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Kavas, Musa. "Optmization Of Tissue Culture, Regeneration And Transformation Parameters In Winter Wheat Cultivars (kiziltan-91 And Bezostaja-01)." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606523/index.pdf.
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The objective of this study was to optimize tissue culture and regeneration
parameters of immature inflorescence culture of Triticum aestivum cv. Bezostaja-
01 and Triticum durum cv. Kiziltan-91. The effects of callus age and vernalisation
time of explants on regeneration success were evaluated. For determination of
optimum vernalisation time of immature inflorescence, plants subjected to 4 °C for 1, 2, 3, 4, and 5 weeks, respectively. Tillers containing immature inflorescences were collected at the same time. Percentage of inflorescence formed tillers over total explants were reached the highest value, 79 %, at 4 weeks cold treated Kiziltan cultivar and, 73 %, at 5 weeks cold treated Bezostaja cultivar. Isolated immature inflorescences were put onto 2mg /L 2,4-dichlorophenoxyacetic acid and picloram containing callus induction medium for Kiziltan and Bezostaja cultures, respectively. Callus induction rate were found to be 100 % for Kiziltan and Bezostaja. These explants were taken to regeneration after 6, 9, 12 and 15 weeks of dark incubation period. The regeneration capacities of calli were determined as shooting percentage and data were collected after 4, 8, 12, and 15 week regeneration period. The highest shooting percentage of 69 %, were obtained from 6 weeks old calli produced from 4 weeks vernalised explants in Kiziltan cultures at the end of 15 weeks regeneration period. However, shooting percentage was 57.2 % for 9 weeks old calli while it decreases to 37.6 % in 12 weeks old calli and 44.2 % in 15 weeks old calli at the end of 15 weeks regeneration period. This showed that prolonged dark incubation period decreased regeneration capacity of the callus. However, there was no significant difference in regeneration capacities of calli produced from Bezostaja immature inflorescence and the highest shooting percentage was obtained from 9 weeks old calli produced from 5 weeks vernalised explants, 27.4 %. Besides regeneration studies, optimization of transformation parameters for winter wheat cultivars Kiziltan and Bezostaja by using Agrobacterium tumefaciens AGLI containing binary vector pALl56 was performed. Transformation efficiencies were determined by monitoring the transient expression of uidA gene via histochemical GUS assay. Three to four weeks old calli were found to be more responsive to Agrobacterium-mediated transformation in Kiziltan cultures. However, four to five weeks old calli were found to be more responsive to Agrobacterium-mediated transformation in Bezostaja cultures. Different transformation protocols were used. It was found that MGL based and MMA based protocols could be used for Bezostaja and Kiziltan transformation, respectively. The highest GUS expression, 84%, was obtained from 28 weeks old calli produced from 5 weeks vernalised explants in Bezostaja cultures.
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Riihimäki, M. A. (Mona-Anitta). "Flowering time and natural selection in Arabidopsis lyrata." Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514277945.
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Abstract
Arabidopsis lyrata is a close outcrossing relative of Arabidopsis thaliana, the model organism of plant physiology and molecular biology. I studied variation in flowering time and the factors shaping the variation within and between A. lyrata populations in different environments. The role of the two important proximate factors determining flowering time, day length and temperature, were studied in climate chambers. The southern A. lyrata populations were found to flower in high frequency and quicker than northern A. lyrata populations in all studied environments, but the reaction of northern populations on long day length was found to be stronger than that of southern populations. Differences in vernalization requirement between A. lyrata populations were found in outdoor common garden, but in the climate chambers the results of vernalization experiments were not consistent. Strength and direction of selection on flowering time and other life history traits were studied in alpine and lowland A. lyrata populations in Scandinavia. Differences in selection were found both between populations and between years. Grazing sheep caused high levels of damage in inflorescences in the alpine population. In the lowland population there was less herbivory, caused by insects and hares. The difference in selection on flowering traits in the two study populations might be partly caused by selective grazing. Completely outcrossing mating system in A. lyrata is due to well developed self-incompatibility system. However, biparental inbreeding is likely to exist in natural populations and it may lead to spatial structuring of genetic variation within populations. I studied the effects of biparental inbreeding on components of fitness in A. lyrata in three different environments. I found inbreeding depression after sib-mating to be substantial. Stressful environment reduced the overall performance of the plants, but had no effect on the magnitude of inbreeding depression. A literature survey indicates that the observed levels of inbreeding depression in self-incompatible A. lyrata were higher than those of self-compatible species. This suggests that self-compatible species have purged some of their genetic load. The genetic basis of flowering time variation in A. lyrata can be further studied by using A. thaliana molecular tools.
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Khan, Abdul Rehman. "Short term response of European wheat populations to contrasted agro-climatic conditions : a genetic analysis and first step towards development of epigenetic markers in earliness gene VRN-A1." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00980832.
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Biodiversity provides the raw material for evolution and adaptation of populations and species. In agricultural biodiversity, the within-population genetic diversity is of major importance. On one hand, it can provide a buffering effect against the year-to-year variation of climate or biotic pressures and on the other hand diversity serves as a resource for the population to respond to selective pressures due to specific local conditions, thus allowing for local adaptation, particularly in the case where a population is introduced into a new location. Due to its wide geographic distribution indicating a high adaptiveotential and its socio-economic importance, wheat was chosen as model crop in this study. Flowering time is a major adaptive trait which has allows wheat to grow over a wide range of ecological and climatic conditions. This PhD study was designed to gain insights about the influence of within population diversity on the short term response of populations to contrasting agro-climatic conditions by studying the genetic, epigenetic and phenotypic variation. But due to the lack of prior existence of epigenetic markers, this thesis study is divided of two parts: In the first part, European wheat populations coming from a set of seven farmer and one modern varieties, each of which was grown on seven farms (distributed across Europe) for three years, were used to study their short term response to contrasting agro-climatic conditions in Europe by analysing their phenotypic and genotypic variations. For the second part the effect of vernalization on the DNA methylation profile of theVRN-A1 gene in winter wheat was studied as a first step towards the development for the epigenetic marker in this gene.The results from the first part of the study revealed that conservation history of these farmer varieties strongly influenced the genetic diversity and fine genetic structure. Ex situ conserved farmer varieties showed low genetic diversity and simpler structure whereas in situ conserved farmer varieties and mixtures revealed higher level of genetic diversity and complex genetic structure. Genetic and phenotypic spatio-temporal differentiation depending upon the level of diversity and structural complexity of the farmer variety was observed. The traditional varieties tend to become more differentiated than the modern variety arguing in favour of use of these diverse traditional (farmer) varieties in organic and low input agriculture systems. Interestingly, a significant phenotypic differentiation for varieties with very low genetic diversity has also been observed in this study, which gives indication of a possible role of epigenetic variation in the process of evolution.From the second part of the study (effect of vernalization on the DNA methylation profile of the VRN-A1 gene), it was found that in addition to the detection of gene body methylation across the VRN-A1 gene, we identified a region within intron 1 that shows significant increase in DNA methylation in response to vernalization treatment that is positively correlated with the gene expression. Although the role of this shift in gene regulation is still unclear due to time limitations in the thesis and the small number of genotypes analysed, this study will provide a good material towards future identification of new epialleles and the development of epigenetic markers to study the epigenetic variability of these populations.This study at large provides useful knowledge on the understanding of farmers' varieties evolutionary response to be used in the development of different breeding and conservation approaches for organic agriculture, taking into consideration of the importance of within population diversity, to satisfactorily address the problems of organic agriculture.
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Alberto, Cleber Maus. "MODELAGEM DO DESENVOLVIMENTO E DO BALANÇO DE ÁGUA NO SOLO EM TRIGO." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/3566.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorWheat is the main winter crop in Rio Grande do Sul State. Temperature and photoperiod are the major environmental factors that control development in wheat. Wheat plants exposed to cold, non freezing temperatures induce them to enter the reproductive phase. Temperature and photoperiod response functions are used to simulate the wheat development. Developmental models are important part of water soil balance, growth and yield crop models. Thus, the objectives of this thesis were: (i) to evaluate vernalization sensitivity of some Brazilian wheat genotypes and to fit a vernalization response function for these genotypes; (ii) to determine the best temperature, photoperiod and vernalization functions to simulate wheat development with the Wang and Engel (WE) model for some Brazilian wheat genotypes; and (iii) to improve the prediction of available soil water in the soil by modifying two mechanistic models. To achieve the first objective, a factorial experiment with eight levels of vernalization (0, 7, 14, 21, 28, 35, 42 and 49 vernalization days) and six wheat genotypes were used. Also a field experiment was carried out in Santa Maria, RS, Brazil, to provide independent data on the date of developmental stages of six Brazilian wheat genotypes for evaluating the original and the modified WE model. Soil water content was determined with the gravimetric method to evaluate water balance models during three sowing dates. For those genotypes that presented some response to vernalization, response functions are presented, which can be used in models for simulating the development of Brazilian wheat cultivars with distinct vernalization requirements. The WE model simulates better the development of the Brazilian wheat genotypes using cardinal temperatures higher than original WE model and using daily maximum and minimum temperatures in the calculation of the temperature response function. The modified Campbell; Diaz water balance model is more realistic and has a greater potential for performing well in regions others than it was developed. The modified Amir; Sinclair water balance model simulates better the available soil water than the original model.
O trigo é a principal cultura de inverno do Estado do Rio Grande do Sul. A temperatura e o fotoperíodo são os dois elementos meteorológicos que mais influenciam o desenvolvimento de plantas de trigo. Quando se expõem plantas de trigo a temperaturas baixas não congelantes, estas podem ser induzidas a entrarem no estágio reprodutivo, diminuindo o seu ciclo de desenvolvimento. Para simular o desenvolvimento do trigo são utilizadas funções de resposta a temperatura e fotoperíodo. O modelo de desenvolvimento é parte importante em modelos de simulação de balanço de água no solo, crescimento e rendimento das culturas. Assim, os objetivos desta tese foram: (i) determinar a sensibilidade à vernalização de alguns genótipos de trigo do sul do Brasil e, ajustar uma função de reposta a vernalização para aqueles que apresentaram sensibilidade; (ii) determinar a melhor função de temperatura, fotoperíodo e vernalização para simular o desenvolvimento de alguns genótipos brasileiros de trigo com o modelo de Wang e Engel (WE); e (iii) obter uma melhor predição do balanço de água no solo, modificando dois modelos mecanísticos de balanço de água no solo. Para atingir o primeiro objetivo, foi conduzido um experimento fatorial com oito níveis de vernalização (0, 7, 14, 21, 28, 35, 42 e 49 dias de vernalização) e seis genótipos de trigo. Também foi realizado um experimento com várias datas de semeadura em Santa Maria, RS, Brasil, para obtenção de dados independentes dos estágios de desenvolvimento de seis genótipos Brasileiros de trigo para avaliar o modelo WE modificado. Foi determinado o conteúdo de água no solo pelo método gravimétrico em três datas de semeadura, com a finalidade de avaliar o desempenho dos dois modelos de balanço de água no solo. Para os genótipos que apresentaram resposta à vernalização são apresentadas funções de resposta, que podem ser usadas em modelos de simulação do desenvolvimento de genótipos brasileiros de trigo. O modelo WE simula melhor o desenvolvimento do trigo quando são usadas as temperaturas cardinais maiores do que as do modelo original e usando as temperaturas mínimas e máximas diária para o cálculo da função de resposta a temperatura. O modelo de balanço de água no solo de Campbell; Diaz modificado é mais realístico e com maior possibilidade de desempenho satisfatório em regiões de clima distinto daquelas em que foi desenvolvido. O modelo de balanço de água no solo de Amir; Sinclair modificado estima melhor a água disponível no solo que o modelo original.
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Verdial, Marcelo Fontanetti. "Frigoconservação e vernalização de mudas de morangueiro (Fragaria x ananassa Duch.) produzidas em sistema de vasos suspensos." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-27082004-171001/.
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Com o objetivo de estudar o sistema de produção de mudas de morangueiro em vasos suspensos e a aplicação das técnicas de frigoconservação e vernalização nas mudas produzidas nesse sistema, foram realizados quatro experimentos no Departamento de Produção Vegetal, ESALQ/USP, Piracicaba/SP, no período compreendido entre janeiro de 2000 e junho de 2003. No primeiro experimento comparou-se o sistema de produção de mudas em vasos suspensos com o sistema convencional. Foram avaliados: matéria seca, teor de carboidratos totais e percentagem de sobrevivência de mudas. Foram utilizadas as cultivares IAC-Campinas, Pelican e IAC-Guarani. Foi utilizado o delineamento experimental em esquema fatorial 3x2 (três cultivares e dois sistemas de produção de mudas), com três repetições. As mudas produzidas em vasos suspensos apresentaram maior percentagem de sobrevivência e maiores teores de carboidratos totais. O segundo e terceiro experimentos tiveram como objetivo avaliar o uso da técnica de frigoconservação em mudas produzidas no sistema de vasos suspensos. As mudas foram acondicionadas em sacos de polietileno e frigoconservadas durante 120 dias em uma B.O.D. a -1 + 1oC. Foram então retiradas da câmara fria e plantadas em bandejas de poliestireno expandido de 128 células preenchidas com vermiculita. As bandejas foram colocadas em uma câmara nebulizadora, onde permaneceram por 21 dias para enraizamento. Em seguida foram transplantadas para vasos de 250ml e levadas para casa de vegetação. Foi avaliada a percentagem de sobrevivência das mudas. No segundo experimento utilizou-se o delineamento experimental inteiramente ao acaso com cinco cultivares (IAC-Campinas, Dover, Pelican, Sequoia e Sweet Charlie) e nove repetições. No terceiro experimento foi utilizado o esquema fatorial 5x2 (cinco cultivares: IAC-Campinas, Oso Grande, Camarosa, Dover e Sweet Charlie; e dois tratamentos de enraizamento: com e sem ácido indol butírico) com quatro repetições. O sistema de frigoconservação adotado apresenou desempenho insatisfatório devido à baixa percentagem de sobrevivência das mudas. O quarto experimento estudou o efeito da vernalização em mudas de cinco cultivares de morangueiro produzidas no sistema de vasos suspensos. As mudas foram plantadas em vasos de 250 ml, preenchidos com substrato formulado com areia e vermiculita (4:1) e mantidas em casa de vegetação durante seis meses. O delineamento experimental utilizado foi o fatorial 5x2, com cinco cultivares (IAC-Campinas, Dover, Sweet Charlie, Cartuno e Oso Grande) com e sem vernalização das mudas, com quatro repetições. Para vernalização, as mudas foram levadas para câmara fria, à temperatura de 10 + 2ºC, e fotoperíodo de 10 h de luz/dia, durante 28 dias. Em seguida, foram transplantadas para dois locais de cultivo com características climáticas distintas, Piracicaba,SP e Caldas,MG. Foram avaliadas as percentagens de sobrevivência, florescimento, frutificação e emissão de estolhos e o peso da matéria fresca e número de frutos produzidos por planta. A sobrevivência de mudas não foi afetada pela vernalização em nenhuma das localidades. Houve efeito significativo no florescimento e na frutificação das plantas vernalizadas apenas em Piracicaba. O estolonamento de plantas foi mais precoce em Piracicaba. Para todas as cultivares a produção de frutos foi e insignificante e comercialmente inviável em ambas as localidades.With the objective of studying the runners production system in suspended pots under protected cultivation and the application of techniques of stored cold and vernalization of runners produced by this system, four experiments were conducted in the Department of Crop Production, ESALQ, Piracicaba, SP-Brazil. In the first experiment it was compared the conventional strawberry runners production system with the runner production system in suspended pots. For that, it was measured the dry matter and carbohydrates contents in runners and the survival percentage when the runner were transplanted to field production areas. The cultivars IAC-Campinas, Pelican and IAC-Guarani were used, in an experimental design of factorial arrangement 3x2 (three cultivars and two runners production systems), three replications. The runners produced by the system of suspended pots accumulated higher amount of total carbohydrates and the plant survival rate. The second and third experiments had the objective of evaluating the use of a technique of storage cold in runners produced in the system of suspended pots. After the selection, the runners were conditioned in polyethylene bags and storage cold conditions for 120 days in a B.O.D. at -1+1ºC. After that they were removed of the cold camera and planted in trays of expanded polystyrene of 128 cells with vermiculite. The trays were put in a spray chamber 21 days for rooting. After that hey were transplanted to pots of 250mL and then placed in the greenhouse. It was evaluated the percentage of runners survival. In the second experiment it was used the experimental entirely random design, five strawberry cultivars (IAC-Campinas, Dover, Pelican, Sequoia and Sweet Charlie), and nine repetitions. In the threat experiment the factorial outline used was 5x2 (five cultivars: IAC-Campinas, Big Oso, Camarosa, Dover and Sweet Charlie; and two treatments: with and without indol butyric acid) with four repetitions. The storage cold of strawberry runners produced in system of suspended pots lower percentage of survival of seedlings in the two experiments. Therefore, the system of storage cold was not compatible with the type of storage runners. The fourth experiment had the objective of studying the effect of the runner vernalization of five strawberry cultivars produced in suspended pot system. In order to have availability of strawberry runners during the off season, they were planted in pots of 250 mL, filled out with substrate formulated with sand and vermiculite (4:1) and kept in the greenhouse for six months. Completely randomized blocks with the factorial design 5x2, with five strawberry cultivars (IAC-Campinas, Dover, Sweet Charlie, Cartuno and Big Oso) and two treatments (with and without strawberry runners vernalization). For vernalization, the strawberry runners were taken from cold camera to the temperature of 10 + 2ºC, and fotoperiod of 10 h of light/day for 28 days. After that, they were transplanted for two cultivation places with different climatic conditions, Piracicaba/SP and Caldas/MG. They were analyzed the survival percentages, flower blooming, fructification and emission of stolons and the weight and number of fruits produced by plant. The strawberry runners survival was not affected by the vernalization in none of the places. There were only significant effect on flower appearance and fructification of the vernalized plants, only in Piracicaba. The runner emitions were earlier in Piracicaba. For all strawberry cultivars the production of fruits was very low and the produced fruits were unsuitable for commercialization in both places.
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Hebrard, Claire. "Contrôle épigénétique de l'induction et de la tolérance à la montaison chez la betterave sucrière." Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00872074.
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La betterave sucrière est une plante bisannuelle dont le besoin de vernalisation est absolu. Ce processus correspond à l'acquisition de l'aptitude à la montaison et à la floraison et résulte d'une exposition prolongée à de basses températures. La durée de froid requise pour induire la montaison puis la floraison varie suivant les génotypes et reflète leur tolérance à la montaison, qui constitue donc un caractère agronomique essentiel. Cette thèse visait à (i) mettre en évidence un éventuel contrôle épigénétique (méthylation ADN) de l'induction de la montaison chez des génotypes de betterave sucrière résistants ou sensibles à la montaison, (ii) identifier les séquences ciblées par des remaniements de méthylation de l'ADN et d'expression associés, et (iii) caractériser certaines séquences candidates en vue de leur utilisation comme marqueurs de la montaison. Nos travaux ont montré que l'amplitude et la cinétique des variations de méthylation de l'ADN observées au cours de la vernalisation semblent être des éléments critiques de l'induction et de la tolérance à la montaison. Par une approche ciblée, des séquences dont la méthylation de l'ADN est remaniée ont été identifiées. L'implication dans la transition florale de deux BvRNMT (RNA METHYLTRANSFERASES) et de la méthylation des ARN, tels que l'ARNm de BvFL1, un répresseur floral, a ainsi été mise en évidence chez la betterave sucrière. Enfin, grâce à une approche génomique, un réseau de gènes intégratif incluant la réponse à l'environnement, la signalisation hormonale et l'induction de la floraison a été identifié. La cinétique d'activation de ces gènes définirait le niveau de tolérance à la montaison des différents génotypes de betterave sucrière.
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Aslan, Selcuk. "The molecular genotyping of flower development genes and allelic variations in ‘historic’ barley accessions." Thesis, Linköping University, Molecular genetics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57106.
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This is a genetic study of flowering time in cultivated barley with the aim to identify the alleles contributing to rapid flowering and frost resistance. We have genotyped a collection of 23 historic barley varieties for the crucial genes [VRN-1, VRN-2, VRN-3 (HvFT), Ppd-H1, CO, and Vrs1]. We have amplified the polymorphic mutations by PCR-based methods, and sequenced them to identify possible haplotype groups. The row type was not determined of all accessions, but all the Scandinavian varieties were found to carry mutant alleles of Vrs1, that indicates them to be six-row barleys. The deletion of the crucial segment of VRN-1 vernalization contributes dominant spring growth habit. We found haplotype groups 2 and 4 to be dominant in Northern barleys whereas haplotype groups 1 and 5 dominated in south. The presence of dominant allele VRN-2 gene is addressed to floral repression until plants get vernalized. Most of the 23 varieties were found to have deleted allele of VRN-2, which is connected with a spring growth habit. The only four of the accessions that have the dominant allele of Ppd-H1 that contribute flowering are generally from the south of Europe. HvFT and CO genes CO-interact to influence flowering time. CO haplotype grouping suggest a geographical distribution of different alleles but needs more disseminations. Certain HvFT alleles cause extremely early flowering during apex development in the varieties that have deletion of VRN-2 alleles under long days. VRN-3 alleles of 14 varieties were identified.
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Lucena, Rafaella Rayane Macedo de. "Desempenho produtivo e qualitativo de cultivares de alho semi-nobre vernalizado na Mesorregião Oeste Potiguar." Universidade Federal Rural do Semi-Árido, 2015. http://bdtd.ufersa.edu.br:80/tede/handle/tede/175.
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Previous issue date: 2015-02-24Conselho Nacional de Desenvolvimento Científico e Tecnológico
Garlic is one of the vegetables of great economic and social relevance in Brazil. Among the consumer states, Rio Grande do Norte, especially, despite having regions with favorable conditions for growing garlic, currently, depends on imports of this product to meet its domestic demand. The introduction of more productive and quality cultivars, better market acceptance, and adjustments of vernalization technology, a key issue for adaptation of new cultivars, are mechanisms that can contribute to garlic revitalization in areas previously producing this vegetable. In order to evaluate the development, production and quality semi-noble garlic cultivars under different periods of pre-planting vernalization of seed bulbs in two city in the Mesoregion West Potiguar, we developed two experiments, simultaneously in Baraúna and Governador Dix-sept Rosado, between the months of April and November 2012. The experimental design was a randomized complete block design with four replications. The treatments were arranged in a split plot, being the plots represented by semi-noble cultivars Gigante do Núcleo and BRS Hozan and subplots consisted by periods of vernalization before planting the seed bulbs at 4 ± 1 ° C: 0, 10, 20 and 30 days. We evaluated: plants emergency, plant height, leaf number, cultural cycle, final stand, mass fresh total, percentage of bulbs differentiation of bulbils, bulbils number, classification of bulbils, bulb average weight, yield total, classification bulbs, diameter of bulb, pH, titratable acidity, soluble solids, total soluble sugars, reducing sugars, pungency, total solids and industrial index. The vernalization did not provide increases significant in productivity, however, the use of 10 day of the vernalization pre-planting seed bulbs allowed in improving the quality of garlic semi-noble produced in Baraúna and Governador Dix-sept Rosado. The cultivars Gigante do Núcleo (4.56 t ha-1) and BRS Hozan (4.42 t ha-1) had higher yields in Baraúna. In this city, garlic produced showed greater diameter, pungency and total solids, with higher industrial index therefore better quality for industrialization (processing or dehydration)
O alho é uma das hortaliças de grande relevância econômica e social no Brasil. Entre os estados consumidores, o Rio Grande do Norte, especialmente, apesar de apresentar regiões com condições favoráveis ao cultivo de alho, atualmente, depende da importação deste produto para atender a sua demanda interna. A introdução de cultivares mais produtivas e de qualidade, com melhor aceitação de mercado, e ajustes da tecnologia de vernalização, ponto fundamental para adaptação de novas cultivares, são mecanismos que podem contribuir para revitalização do alho em regiões, anteriormente produtoras desta hortaliça. Com o objetivo de avaliar o desenvolvimento, produção e qualidade de cultivares de alho semi-nobre, submetidas a diferentes períodos de vernalização pré-plantio dos bulbos-semente em dois municípios da Mesorregião Oeste Potiguar, desenvolveram-se dois experimentos, simultaneamente, em Baraúna e Governador Dix-sept Rosado, entre os meses de abril e novembro de 2012. O delineamento experimental foi o de blocos completos casualizados com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas, sendo as parcelas representadas pelas cultivares semi-nobres Gigante do Núcleo e BRS Hozan e as subparcelas constituídas pelos períodos de vernalização pré-plantio dos bulbos-semente à 4 ± 1 ºC: 0, 10, 20 e 30 dias. Foram avaliados: emergência de plantas, altura de plantas, número de folhas, ciclo cultural, estande final, massa fresca total, percentagem de bulbos com diferenciação de bulbilhos, número de bulbilhos, classificação de bulbilhos, massa média de bulbos, produtividade total, classificação de bulbos, diâmetro de bulbos, pH, acidez titulável, sólidos solúveis, açúcares solúveis totais, açúcares redutores, pungência, sólidos totais e índice industrial. A vernalização não proporcionou aumentos significativos na produtividade, entretanto o uso de 10 dias de vernalização pré-plantio dos bulbos-semente possibilitou incrementos na qualidade do alho semi-nobre produzido em Baraúna e Governador Dix-sept Rosado. As cultivares Gigante do Núcleo (4,56 t ha-1) e BRS Hozan (4,42 t ha-1) apresentaram maior produtividade em Baraúna. Neste município, o alho produzido apresentou maior diâmetro, além de pungência e sólidos totais, com índice industrial mais elevado e, portanto, melhor qualidade para industrialização (processamento ou desidratação)
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Kemi, U. (Ulla). "Adaptation to growing season length in the perennial Arabidopsis lyrata." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526203201.
Full textAbstract:
Abstract Adaptation to local environment is important for all organisms to guarantee survival and to maximize reproduction. Populations of the same species may live in environments that differ markedly. Due to differential selection pressures this can lead to population differentiation, which can be studied both at the phenotypic and at the gene level. The growing season cued by long days is typically short in the north, whereas southern populations have long growing seasons and are adapted to short days. Seasonal fluctuations in temperature also differ between northern and southern environments. Daylength and temperature regulate the timing of flowering in plants. Environmental regulation of flowering and its genetic basis has been extensively studied in the annual model species Arabidopsis thaliana. The perennial growth and flowering habit has been studied especially in trees, but studies on herbaceous plants species have been lacking. In this thesis, I have studied adaptation to growing season length in a perennial herbaceous model species Arabidopsis lyrata. Individuals from populations adapted to northern and southern environments in Europe were grown in same conditions in the growth chambers and in the field. Differentiation between the populations was studied by observing their flowering phenotypes and by studying the expression of genes that are candidates for governing the phenotypic differentiation. The main result in the thesis was that adaptation to short growing season in north can be seen as long daylength requirement for flowering and as fast developmental rate. Critical daylength for flowering likely regulates especially the timing of flowering cessation in the end of the growing season. Flowering time of individuals from northern populations also responded more strongly to cold treatment (representing winter) than that of the southern population. The cold requirement for flowering guarantees that the plants only flower after the winter in the spring with suitable conditions. Expression studies indicated that population differentiation in flowering could be at least partly governed by the expression variation in a few candidate genes. The results in this thesis are valuable for instance for understanding perennial species in general, including tree and crop species, and for predicting how plants response to changing climateTiivistelmä Ympäröiviin oloihin sopeutuminen on tärkeää kaikille organismeille selviytymisen ja jälkeläistuoton kannalta. Saman lajin eri populaatiot saattavat elää ympäristöissä, joiden olosuhteet poikkeavat toisistaan huomattavasti. Tällöin populaatioihin kohdistuvat erilaiset valintapaineet ja populaatiot erilaistuvat. Erilaistuminen havaitaan tarkastelemalla yksilöiden ilmiasuja ja geenejä. Kasvukauden pituus määrittää eteläisten ja pohjoisten kasvuympäristöjen valintapaineita. Pohjoisessa kasvukausi on lyhyt ja sen alkamisesta ja loppumisesta kertoo pitkä päivänpituus. Etelässä on pitkä kasvukausi ja siellä elävät populaatiot ovat sopeutuneet lyhyeen päivänpituuteen. Myös vuodenaikaiset lämpötilavaihtelut eroavat pohjoisten ja eteläisten alueiden välillä. Muutokset päivänpituudessa ja lämpötilassa säätelevät kasveilla kukkimisen ajankohtaa. Kukkimiseen vaikuttavia ympäristötekijöitä ja kukkimista sääteleviä geenejä on tutkittu paljon yksivuotisella mallilajilla lituruoholla (Arabidopsis thaliana). Monivuotisten kasvien kasvun ja kukkimisen säätelyä on tutkittu etenkin puilla, mutta hyvin vähän ruohovartisilla kasveilla. Tässä väitöskirjatyössä tutkin kasvukauden pituuteen sopeutumista monivuotisella ruohovartisella lajilla, idänpitkäpalolla (Arabidopsis lyrata). Pohjoisiin ja eteläisiin ympäristöoloihin sopeutuneiden eurooppalaisten populaatioiden yksilöitä kasvatettiin samanlaisissa olosuhteissa kontrolloiduissa kasvatushuoneissa ja kenttäolosuhteissa. Populaatioiden erilaistumista tarkkailtiin kukkimiseen liittyvissä ominaisuuksissa sekä eroja selittävien kandidaattigeenien ekspressiossa. Tutkimuksen päätulos oli, että pohjoisen populaation lyhyeen kasvukauteen sopeutuminen voidaan havaita pitkän päivän vaatimuksena kukkimiselle ja nopeana kehityksenä. Kenttäolosuhteissa päivänpituus sääteli etenkin kukkimisen lopetusta kasvukauden lopussa. Pitkä kylmäkäsittely nopeutti kukkimista etenkin pohjoisessa populaatiossa. Kukkimista edeltävä kylmävaatimus takaa, etteivät kasvit kuki syksyllä epäsuotuisissa olosuhteissa, vaan vasta keväällä talven jälkeen. Populaatioiden erilaistuminen kukkimisen päivänpituus- ja kylmävaatimuksessa selittyy todennäköisesti ainakin osittain kandidaattigeenien ekspressioeroilla. Tämän väitöskirjatyön tuloksia voidaan soveltaa monivuotisten viljelykasvien jalostuksessa tai ennustettaessa kasvipopulaatioiden sopeutumista ilmastonmuutokseen
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Brugidou, Christophe. "Developpement de digitalis lanata (ehrh. ) et selection pour la production d'un heteroside cardiotonique : la digoxine." Paris 6, 1987. http://www.theses.fr/1987PA066288.
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Netzer, Marie-Hélène. "Recherches sur le déterminisme de la floraison de 3 cvs de Brassica napus L. Var. Oleifera en conditions contrôléesS." Paris 6, 1986. http://www.theses.fr/1986PA066130.
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L'influence des facteurs de l'environnement sur la floraison et le développement inflorescential de 3 cvs de b. Napus var. Oleifera ont été étudiés dans les conditions contrôlées du phytotron. Le besoin de vernalisation n'est pas absolu pour les trois cultivars. Les températures basses favorisent toujours la floraison en permettant une initiation florale plus précoce et un nombre final de feuilles de l'axe principal plus faible. La précocité de l'initiation florale et le nombre final de feuilles sont liés.
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Lin, Min. "Effects of Vernalization Duration, Light Intensity during Vernalization and Low Temperature Holding after Vernalization on Flowering of Nobile Dendrobium Hybrids." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9447.
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Flowering time and flower quality of three nobile dendrobium hybrids in relation to vernalization duration and light intensity during vernalization were studied in the first experiment. Mature Dendrobium Red Emperor 'Prince', Dendrobium Sea Mary 'Snow King', and Dendrobium Love Memory 'Fizz' were cooled at 10 degrees C with 300 to 350 mol·m–2·s–1 photosynthetic photon flux (PPF) (12-h photoperiod) or darkness, each with four cooling durations (2, 4, 6, or 8 weeks). Plants were forced in a greenhouse after vernalization. At least 4 weeks of 10 degrees C cooling in light was needed for flower initiation of Red Emperor 'Prince'; whereas Sea Mary 'Snow King' and Love Memory 'Fizz' only needed 2 weeks of 10 degrees C cooling regardless of light. Darkness during vernalization slightly delayed flowering and resulted in fewer but larger flowers. Longer cooling duration delayed flowering, decreased the flower longevity, and produced larger and more flowers. In the second experiment, Love Memory 'Fizz' were cooled at 15 degrees C for 4 weeks with PPF of 0, 50, 100, or 200 mol·m–2·s–1 (12-h photoperiod). Compared to 200 mol·m–2·s–1, low PPF of 50 or 100 mol·m–2·s–1 did not affect flowering time or flower quality; however, darkness delayed flowering and reduced flower quality. The third experiment was aimed at developing a strategy to defer flowering of nobile dendrobium orchids by holding them under low temperature. Mature Den. Red Emperor 'Prince' and Den. Sea Mary 'Snow King' were held at 10 degrees C for various durations (0, 4, 8, 12 or 16 weeks) after vernalization (4 weeks at 10 degrees C). Plants were forced in a greenhouse after holding. Time to flowering, flower differentiation and flower quality were determined. Increase of low temperature holding duration from 0 to 16 weeks extended time to flowering up to 3 months and did not affect parameters of flower except producing larger flowers and reducing flower number per flowering node for Den. Red Emperor 'Prince'. Notably, the flower longevity was not adversely affected. Defoliation was aggravated in Den. Red Emperor 'Prince' by longer duration of cooling and was considered a detrimental effect of low temperature holding.
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Zografos, Brett Robert. "Mechanisms underlying vernalization-mediated VERNALIZATION INSENSITIVE 3 (VIN3) induction in Arabidopsis thaliana." Thesis, 2013. http://hdl.handle.net/2152/25183.
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Vernalization is defined as the response to prolonged cold exposure required for acquiring the molecular competence necessary to undergo floral transition. FLOWERING LOCUS C (FLC), a potent floral repressor in Arabidopsis, is highly expressed before vernalizing cold treatment but is repressed during prolonged vernalization. VERNALIZATION INSENSITIVE 3 (VIN3) is a Plant HomeoDomein (PHD)- containing protein that is required for establishing vernalization-mediated repression of FLC. The induction of VIN3 is one of the earliest molecular events in vernalization response and its expression is intimately linked to prolonged cold exposure. However, mechanisms underlying VIN3 induction remain poorly understood. The constitutive repression of VIN3 in the absence of cold is due to multiple repressive components, including a transposable element-derived sequence, LIKE-HETEROCHROMA TIN PROTEIN 1 (LHP1), and POLYCOMB REPRESSION COMPLEX 2 (PRC2). Furthermore, the full extent of VIN3 induction by vernalization requires activating complex components, including EARLY FLOWERING 7 (ELF7) and EARLY FLOWERING IN SHORT DAYS (EFS). Dynamic changes in the histone modifications present at VIN3 chromatin during vernalization were also observed, indicating that chromatin changes play a critical role in regulating VIN3 induction. However, VIN3 induction by vernalization still occurs in the absence of activation complexes and de- repression of VIN3 in the absence of the repressive complexes is not sufficient for achieving complete induction. Thus, unknown cold-influenced regulators responsible for achieving maximum VIN3 induction during vernalization must exist. Therefore, forward genetic screening was undertaken to elucidate upstream regulators of VIN3. Molecular characterization of T-DNA mutant populations elucidated two interesting mutants: a mutant that ectopically expressed VIN3 before cold (ectopic VIN3 induction, evi1) and mutants that failed to induce VIN3 during vernalization (defects in VIN3 induction, dvi1). FLC is over-expressed in dvi1 despite its failure to induce VIN3 expression during vernalization, suggesting that this mutant may regulate both VIN3 and FLC. In evi1, FLC is hyper-repressed after 40 days of vernalization, leading to an acceleration of flowering time. These results indicate that regulators of VIN3 in the vernalization pathway exist and that these regulators may use different mechanisms in order to influence VIN3 expression.text
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Baloch, Dost M. "Vernalization requirement studies with Pacific Northwest wheats." Thesis, 1994. http://hdl.handle.net/1957/35144.
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Tan, Chor Tee. "Genetic loci for vernalization requirement duration in winter wheat." 2008. http://digital.library.okstate.edu/etd/Tan_okstate_0664M_10049.pdf.
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Fandrich, Lynn. "Vernalization requirements and seed dormancy of jointed goatgrass (Aegilops cylindrica)." Thesis, 2005. http://hdl.handle.net/1957/28806.
Full textAbstract:
Jointed goatgrass (Aegilops cylindrica Host) infestations in winter wheat
(Triticum aestivum L.) production regions of the central and western USA result in severe
economic losses in the wheat market. Field and greenhouse studies were conducted to
determine the vernalization requirements of winter wheat, spring wheat, jointed
goatgrass, and wheat by jointed goatgrass reciprocal hybrid plants. In field studies,
jointed goatgrass plants required more vernalization to produce spikelets and germinable
seed than 'Madsen' winter wheat plants. In greenhouse studies, plants of jointed
goatgrass populations collected from Oregon and Washington wheat fields required fewer
vernalization days to reach the joint stage than Madsen plants. Detailed observations in
the greenhouse revealed a longer period between jointing and anthesis for most jointed
goatgrass populations that was overlooked in field studies. Vernalization for 6-wk
represents the minimum treatment for synchronous reproductive development among
jointed goatgrass populations, Madsen winter wheat, and Madsen by jointed goatgrass
hybrids, yet the risk of gene transfer might be greater after 7-wk vernalization. In the
jointed goatgrass populations tested, there was not selection for a vernalization
insensitive growth habit. Because jointed goatgrass spikelets often contain two seed,
germination was recorded for primary and secondary positioned seed. Germination of
freshly harvested jointed goatgrass seed was promoted by 25/15 C day/night
temperatures. However, light and 30/20 C incubation was necessary for maximum
germination of non-dormant, primary positioned seed. Both primary and secondary
positioned seed within jointed goatgrass spikelets were non-dormant after 16-wk after-ripening
at 22 ± 2 C. Under optimum growing conditions, no planting depth selectively
allowed wheat germination and emergence while preventing jointed goatgrass
germination and emergence. Glume removal did not alleviate dormancy completely in
jointed goatgrass seed. Research confirmed jointed goatgrass population polymorphism
for vernalization requirements and seed dormancy. Jointed goatgrass reproductive
variability might be part of a general purpose genotype strategy to germinate and
colonize a wide range of environments. Wheat by jointed goatgrass hybrid plants should
be removed from winter and spring wheat fields. Despite a short dormancy period, three
or more years of rotation outside of winter annual crops may be necessary to reduce
populations of jointed goatgrass.Graduation date: 2006
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Greenup, Aaron Geoffrey. "The molecular mechanisms of vernalization induced flowering in temperate cereals." Phd thesis, 2011. http://hdl.handle.net/1885/151298.
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Plants coordinate development with environmental cues to ensure flowering occurs under optimal seasonal conditions. Many plants from temperate regions only flower after exposure to prolonged cold: vernalization. While the molecular mechanisms of the vernalization response have been studied extensively in the model plant Arabidopsis, this seasonal flowering response has probably evolved independently in other plants. For instance, no homologues of FLOWER LOCUS C (FLC), the gene central to the vernalization response in Arabidopsis, have been found in economically important crops such as barley and wheat. Instead VERNALIZATION1 (VRN1) is central to the vernalization response in these plants. This highlights a need to study the vernalization response directly in cereal crop species. Previous studies have identified VRN1 as a master regulator of the vernalization response in cereals, but the extent to which other genes contribute is unclear. To identify genes that are potentially involved in regulating the vernalization response the Barley1 Affymetrix chip was used to compare gene expression in barley seedlings during short or prolonged cold treatments. Additionally, gene expression was assayed when plants were shifted to normal growth temperatures following prolonged cold treatment. This identified genes that show lasting changes in transcriptional activity, which might contribute to vernalization-induced flowering. Only a small group of genes showed a lasting change in activity when plants were shifted to warm conditions following prolonged cold. These included VRN1 and another MADS box gene, ODDSOC2 (OS2). OS2 belongs to a group of MADS box genes only found in grasses. Expression analysis showed that OS2 is down-regulated by cold and that long term repression of OS2 is dependent on VRN1. Overexpression of OS2 in barley delayed flowering and caused dwarfing. These phenotypes could be due to the down-regulation of FLOWERING PROMOTING FACTOR1 (FPF1)-like genes. In Arabidopsis FPF1 promotes flowering and elongation. Thus down-regulation of OS2 likely contributes to the acceleration of flowering through the de-repression of FPF1-like genes as daylength increases in spring. To determine if any components of the vernalization response pathway are conserved between Arabidopsis and temperate cereals, barley homologues of the Arabidopsis MADS box gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) were identified and characterised. In Arabidopsis SOC1 promotes flowering and is positively regulated by vernalization, long-days, and development. Similar to SOC1, the expression of a barley SOC1-like genes increases during development. Unlike Arabidopsis, the expression of a barley SOC1-like gene, HvSOC1-like1 was similar regardless of daylength suggesting that photoperiod does not regulate the expression of these genes. The regulation of HvSOC1-like genes by vernalization is also different. The expression of HvSOC1-like genes was lower in the leaves and crown tissue of vernalized plants versus non-vernalized plants. Over-expression of one of the barley SOC1-like genes, HvSOC1-like1, delayed flowering and caused dwarfing in barley plants. The phenotypes of these plants are different SOC1-like genes. Overall these data suggest that cereal SOC1-like genes have evolved differently and have different regulatory functions than SOC1 from Arabidopsis. Overall the findings from this thesis extend our understanding of the vernalization response in temperate cereals and highlight the difference of how this seasonal flowering response is regulated in temperate cereals and Arabidopsis. Since VRN1 is one of only a limited number of genes that initiates flowering in temperate cereals, understanding how VRN1 is regulated and identifying the targets of VRN1 will be of critical importance to understanding the mechanisms of seasonal flowering responses in these plants.
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Yang, Shun-Min, and 楊舜閔. "Cloning and Transformation of Vernalization-Related Genes in Nobile Type Dendrobium Orchid." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/78688958865917801371.
Full textAbstract:
碩士國立中興大學
園藝學系所
103
Nobile type Dendrobium is a section of Dendrobium that includes many closely related species and their hybrids. Nobile-type Dendrobiums are cultivars bred mainly from Dendrobium nobile. Nobile type Dendrobium is a new orchid crop to be promoted in Taiwan due to its potentials in economic cultivation. Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process. In Taiwan, the culture practice is bringing the pot plants to higher elevation or flower forcing in cold room to satisfy the chilling requirement. The mechanism of vernalization in Dendrobium nobile has been elucidated recently and has revealed ways to regulate flowering of Nobile type Dendrobium. The objective of this study is to develop the innovative biotechnologies for regulating flowering of Nobile type Dendrobium with uniform flowering, low cost, and high marketing value via transformation of vernalization-related genes VRN1 and AGL19. A suitable production system for protocorm-like bodies (PLBs) induction and proliferation of nobile type Dendrobium was established from seeds germinated in vitro. VRN1, AGL19, and FT cDNAs had been cloned from nobile type Dendrobium and verified by DNA sequence analysis. Plant transformed vectors harboring the VRN1, DnAGL19, SOC1, and FT genes under the control of constitutive (using CaMV 35S promoter and constructed into pCAMBIA 2301 and pCAMBIA 1304), tissue specific (using AP1 promoter and constructed into p1304-AP1-IN) or alcohol inducible (using AlcR/AlcA system and constructed into pBJ36-AlcA and pMLBART-AlcR) expression had been constructed. VRN1 and AGL19 genes were co-transformed into the PLB of the nobile type Dendrobium by Agrobacterium-mediated transformation. The regenerated plantlets were selected by antibiotics. The results of GUS activities, PCR and RT-PCR analysis of putative transgenic leaves indicated that the transformed genes were presented in the genome of transformed plantlets, and expressed its mRNA.
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Bond, Donna Maree. "The regulation and function of VERNALIZATION INSENSITIVE 3 (VIN3) in Arabidopsis thaliana." Phd thesis, 2009. http://hdl.handle.net/1885/150793.
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Pan, Aihong. "Genetic analysis of vernalization, photoperiod, and winter hardiness in barley (Hordeum vulgare L.)." Thesis, 1994. http://hdl.handle.net/1957/35740.
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Schmitz, Robert J. "Vernalization : a model for investigating epigenetics and eukaryotic gene regulation in Arabidopsis thaliana /." 2007. http://www.library.wisc.edu/databases/connect/dissertations.html.
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Chen, Yi-Chen, and 陳羿蓁. "Effects of Grafting and Vernalization on the Flowering and Head Quality of Cabbage." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/83939719516016297980.
Full textAbstract:
碩士國立臺灣大學
園藝暨景觀學系
104
Cabbage (Brassica oleracea L. var. capitate) is plant-vernalization-responsive type plant which requires vernalization to induce flowering in tropical and subtropical lowland areas where lack sufficient low temperature. Grafting is widely used in commercial production of cucurbits and solanaceous vegetables, so as to, e.g., improve resistance to soil-borne diseases and tolerance to abiotic stresses, promote plant vigor, increase yield, and induce or promote flowering. This research aims to set up the healing conditions for cabbage grafting, and investigate effects of grafting and vernalization on flowering, gene expression levels of flowering related genes and leaf head qualities, though four experiments. In experiment I, the best healing conditions for grafted cabbage seedlings were developed. The highest survival rate of grafted seedlings was found under healing conditions of 15℃, relative humidity (RH) 85%, and dark or high light intensity (79~107 μmol∙m-2∙s-1). On the growth of grafted cabbage seedlings after grafted 35 days, the highest seedling index was shown under healing conditions of 20℃, RH 75% or 95%, and high light intensity (79~107 μmol∙m-2∙s-1). Experiment II investigated the effects of different species and cultivars of rootstock on flowering and leaf head qualities in grafted cabbage plants. Cabbage ‘K-Y cross’ grafted onto different rootstocks did not promote flowering. Cabbage ‘K-Y cross’ grafted onto Chinese kale rootstocks ‘Jie Lan’ had significant higher content of ascorbic acid and total soluble solids in leaf head than cabbage ‘K-Y cross’ self-grafted or ungrafted plants, but only when grown in containers. Experiment III investigated the effects of vernalization on flowering and gene expression levels of flowering related genes in grafted cabbage plants. Cabbage ‘K-Y cross’ grafted onto Chinese kale cv. ‘Cuei Jin’ rootstock (C/K), treated with 5℃ or 10℃ artificial vernalization for 6 weeks, and then transplanted to 25/20℃ environment did not flower. Although expression level of BoFLC4-1 reduced, while BoVIN3 and BoFT increased as the vernalization time extented. However, the expression levels of BoFLC4-1, BoVIN3 and BoFT in C/K were not changed much faster than that of self-grafted or ungrafted cabbage plants. Grafted cabbage plants with different rootstocks grown in highland for natural vernalization flowered earlier than that grown in sea level, but days to flowering in grafted cabbage with different rootstocks were not earlier than that of self-grafted or ungrafted cabbage plants. In experiment IV, we try to grafted cabbage ‘K-Y cross’ on the flowering stalk of Chinese kale ‘Cuei Jin’, but it still cannot induce or promote flowering. In conclusion, even though grafted cabbage on rootstocks of different Chinese kale cultivars or cabbage cv. ‘He Fong’ could not promote flowering, but the research developed the best healing conditions for grafted cabbage seedlings which could be used to test the possibility of flowering promotion when combination with different rootstock species or be applied in other grafting purposes in the future.
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Ortega, Martinez R. "The role of the FT genes in the control of flowering in chickpea." Thesis, 2018. https://eprints.utas.edu.au/28596/1/Ortega_Martinez_whole_thesis.pdf.
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The transition from vegetative to reproductive stage is one of the most significant in the life cycle of any plant. Variation in flowering time allows species to colonize new habitats, and from an agricultural point of view is crucial to adapt crops to different environments and maximise yield. This is particularly important in the case of chickpea, which is cultivated in diverse environments in more than 50 countries. In most of these environments, early phenology plays a key role as an adaptation that allows the crop to escape unfavourable conditions. Therefore, flowering time is one of the most extensively studied traits in chickpea and numerous QTL studies have been published on this topic. FLOWERING LOCUS T (FT) is a key gene promoting flowering in Arabidopsis thaliana, and FT homologs are involved in the control of floral transition across plant kingdom, including legumes. This study investigated the putative role of CaFT homologues in the genetic control of flowering in chickpea.
The molecular control of flowering time is well understood in model species, particularly Arabidopsis, which is the most suitable model for comparison with temperate legumes in view of its taxonomic position and nature of its flowering responses. This study explored the conservation and position of Arabidopsis flowering-related genes across chickpea genome, and discussed their co-localization with some reported flowering QTLs, focussing in particular on a central portion of chickpea chromosome 3 that has been recurrently associated with flowering in several mapping populations and published studies. The most plausible candidates in this region, belonged to the well-known CONSTANS-Like (COL) and FT gene families and these gene families were therefore characterised.
Three different intra- and inter-specific chickpea populations were used in this study to investigate in more detail the possible identity of the genes underlying the co-localized flowering time QTLs on chromosome 3. QTL analysis and differential expression profiles in the three populations identified a cluster of three FT homologs (FTa1-FTa2-FTc) as the genes most likely to be responsible for the majority of the phenological difference between wild and cultivated chickpea. In contrast, in the intraspecific population, this locus has a lesser role that was secondary to a major locus in another region of chromosome 3. QTL analysis of shoot architecture traits revealed major loci controlling growth habit (erectness) and branching tendency between C. arietinum and C. reticulatum located in the same interval of chromosome 3, indicating a possible pleiotropic role of FT genes in control of shoot architecture. The growth habit QTL is likely equivalent to the previously-described growth habit locus Hg, suggesting that the FT cluster should be considered candidates for this locus.
In view of their potential to influence chickpea phenology and thus its adaptation to different environments, sequence variation of the chickpea FTa1-FTa2-FTc cluster was examined in a panel of 96 accessions (94 C. arietinum and 2 C. reticulatum) through a targeted next-generation sequencing approach. This analysis showed that despite high conservation within the coding regions, the regulatory and intergenic regions are very divergent in the wild and domesticated species. Among domesticated accessions, the intergenic region between FTa1 and FTa2 shows the highest level of polymorphism, including the total deletion of the FTa2 gene and a 753 bp insertion that could be associated with variation in flowering time.
Vernalization response has been a controversial topic in chickpea. Unlike C. reticulatum from which it derives, C. arietinum has been traditionally considered as a vernalization-insensitive species. However, more recent evidence points to the existence of two distinct vernalization response patterns within cultivated germplasm. This study evaluated the flowering phenotype of two wild and six cultivated chickpea accessions in response to vernalization and photoperiod, and the potential role of the chickpea FT homologs in these pathways was investigated through analysis of their expression patterns. The results indicate that a response to vernalization exists in all C. arietinum accessions, and suggest that the FTa1 gene may be particularly important in the signalling and integration of photoperiod and vernalization responses. The convergence of these two pathways on overlapping groups of FT genes may explain why a subset of chickpea accessions behave like they are vernalization insensitive under flowering-inductive photoperiods.
Overall, the results obtained in the present study make a significant contribution to the current understanding of regulation of flowering time and growth habit in chickpea, including the molecular basis for a major flowering time locus and potential roles for FT homologues in the control of flowering time in both wild and domesticated chickpea.
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Lee, Hsiang-I., and 李香誼. "The Study on Vernalization Affecting Summer Yield in Cauliflower (Brassica oleracea var. botrytis L.)." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/38551019585042037257.
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YaFangLee and 李雅芳. "Effect of Temperature and Seedling Age of Vernalization on Celery (Apium graveolens L.) Growth." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/37353822087705783416.
Full textAbstract:
碩士國立臺灣大學
園藝學研究所
90
To assess the temperature effect on vegetative and reproductive growth in celery(Apium graveolens L.), leaf formation, plant height and other growth characteristics are monitored in two local varieties cvs. ‘Hainan-Chin’ and ‘Huang-Hsin’. The study also found out the effects of vernalization and seedling age on bolting and flowering are studied with 4 varieties, cvs. ‘Hainan-Chin’(green leaf and petiole)、‘Huang-Hsin’(yellow leaf and petiole)、‘Shii-Shu Late’(green leaf yellow petiole) and ‘Ching-Torng’(green flower stalked). In the phytotron of National Taiwan University, day/night temperatures of 35/30, 30/25, 25/20, 20/15, and 15/13℃ formulated the temperature treatments. For both celery cultivars the vegetative growth was retarded under 35/30℃ and 30/25℃ regimes in terms of shorter petiole, smaller stem girth and smaller biomass. The celery ‘Hainan-Chin’ grows fetter in 20/15℃ temperature treatment while cv. ‘Huang-Hsin’ is more susceptible to high temperature stress, for good growth under 15/13℃. The relative growth rate (RGR) for ‘Hainan-Chin’ was highest at 46~60 DAS (days after sowing) and decreased along the growth period；also the RGR was reduced in 35/30℃ and 30/25℃. The result was similar to cv. ‘Huang-Hsin’. The rate of leaf formation was in a linear relationship with the temperature. Day/night temperature of 35/30℃ was detrimental to leaf formation. Growing under 20/15℃, cvs. ‘Hainan-Chin’ and ‘Huang-Hsin’ developed 7.2 and 7.0 leaves with an average rate of 0.8 and 0.7 leaves after every 10 days, respectively 84 days of sowing；The corresponding values obtained under 35/30℃were 5.8 and 5.0 leaves developed and at a rate of 0.5 and 0.3 leaves every 10 days, respectively. Various growth characteristics and leaf formation were higher at 15~22℃ for both varieties, it indicated the optimum temperature range for celery growth. Various reproductive growth characteristics were evaluated on seedling of 3 different ages (28, 42 and 56 d) either vernalized under 5℃ for 21 days or untreated before transplanting. Upon transplanting, the untreated control plants grew taller than other vernalized plants. However as the vernalized plants bolted later, there was no significant differences in plant height for all treatments at harvest, all plants grew to a height of 120~135㎝. There was no interaction of seedling ages and cultivars. Celery ‘Ching-Torng’ of 56d of age bolted ever under 20/15℃ before transplanting. Among the other three cultivars: ‘Huang-Hsin’ had the earliest bolting and flowering, followed by ‘Shii-Shu Late’, and ‘Hainan-Chin’ in that order. Thus, cv. ‘Huang-Hsin’ was the most sensitive to cold temperature and ‘Hainan-Chin’ had more low temperature requirement to be induced. Also ‘Hainan-Chin’ adapted the best with the largest plants, and highest total umbels. The younger seedlings (28d) responded less to vernalization than older seedlings (42b and 56d) after transplanting. This was determined by rate of stem elongation, time course to complete bolting and flowering, total umbels and dry matter percentage to flowers and seeds.
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Genger, Ruth Kathleen. "Cytosine methylation, methyltransferases and flowering time in Arabidopsis thaliana." Phd thesis, 2000. http://hdl.handle.net/1885/47082.
Full textAbstract:
Environmental signals such as photoperiod and temperature provide plants with seasonal information, allowing them to time flowering to occur in favourable conditions. Most ecotypes of the model plant Arabidopsis thaliana flower earlier in long photoperiods and after prolonged exposure to cold (vernalization). The vernalized state is stable through mitosis, but is not transmitted to progeny, suggesting that the vernalization signal may be transmitted via a modification of DNA such as cytosine methylation. The role of methylation in the vernalization response is investigated in this thesis. ¶ ...
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Liou, Chia-Ching, and 劉佳晴. "Functional Characterization of the Non-vernalization Responsive Flowering Gene, BoFLC3, in Broccoli(Brassica oleracea var. italica)." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/n32e5v.
Full textAbstract:
碩士國立臺灣大學
農藝學研究所
107
Broccoli (Brassica oleracea var. italica) is one of the important vegetables in the world. Understanding the molecular mechanism of broccoli flowering time can assist the breeding of broccoli with various flowering time for shift production. BoFLC3 has been shown to be associated with the flowering time of non-vernalization type broccolis by the linkage analysis and candidate gene approach. BoFLC3 alleles of late-flowering and early-flowering inbred lines exhibited 3 amino acid substitutions and a 255-bp indel polymorphism in intron I. To validate the function of BoFLC3 conferring flowering time, the full-length genomic DNA of the two BoFLC3 alleles were constructed after 35S promoter and then transformed to an ecotype Arabidopsis, Col-0. The overexpression of both two BoFLC3 alleles postponed flowering initiation, revealed that BoFLC3 played a similar role as AtFLC in inhibition of flowering time and both two BoFLC3 alleles were functional. In addition, promoter assays of two BoFLC3 alleles exhibited 244-bp and 678-bp indel polymorphisms were measured to reveal the importance of these two indels on promoter regions on the expression of BoFLC3. The two insertions in the BoFLC3-1 allele had relative lower promoter activity, implying less repression effect of BoFLC3 on FT associated with earlier flowering than the BoFLC3-2 allele. Furthermore, a stable transformation system of broccoli was established for further characterizing the function of BoFLC3 in broccoli by overexpression and/or genome editing. This study sheds light on the manipulation of BoFLC3 on the breeding of non-vernalization type broccoli with various flowering time to adjust production for food resilience.
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Bilodeau, Pierre. "Molecular cloning and expression of a vernalisation-induced cytochrome P450 gene from Arabidopsis thaliana." Phd thesis, 1996. http://hdl.handle.net/1885/144369.
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