Dissertations / Theses: 'Wheat genotypes'

1

Hendawy, Salah El-Sayed el. "Salinity tolerance in Egyptian spring wheat genotypes." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972317627.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Khan, Javed Ahmad. "Salinity effects on 4D recombinant tetraploid wheat genotypes." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321525.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Rashid, Kazi Nayla. "The response of wheat genotypes to inoculation with Azospirillum brasilense." Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/12898.

Full text

Abstract:

It is well documented in many studies that plant growth promoting rhizobacteria (PGPR) are capable of increasing plant growth and productivity in a range of agricultural crops, reducing dependence on chemical amendments and maintaining a safe environment. Over the last two decades PGPR inoculants have been increasingly used in agriculture to improve crop productivity and farming system sustainability. Such eco-friendly technologies are needed to address sustainable food security and to avoid global dependence on hazardous agricultural chemicals which ultimately destabilize agro-ecosystems. The nitrogen fixing bacteria, Azospirillum brasilense, has been an important PGPB (plant growth promoting bacteria) used to enhance the growth and yield of many crops globally. This is attributed mainly to its ability to produce phytohormones. While much is known about A. brasilense, the promising effect of PGPBs in general in the field is limited by factors that influence their survival and activity in the rhizosphere. The attachment of bacteria to roots is an essential and necessary condition for the establishment of an effective association. This association is dependent upon the population density of active PGPB cells in the rhizosphere which are able to compete with indigenous bacteria. However, how survival and persistence of inoculant bacteria in the rhizosphere, the effect of inoculum on the rhizosphere community, in particular the nitrogen fixing community, and the effect of plant genotype contributes to plant growth promotion by Azospirillum in the field have not been widely studied. Better understanding of the plant x inoculum interaction requires determining if there is an effect of plant genotype and monitoring and estimation of the persistence of PGPB in the rhizosphere. The overall aim of this project was to examine the effect of the wheat (Triticum aestivum) genotype x Azospirillum interaction on colonization of roots and plant growth promotion. These effects were studied under both controlled hydroponic conditions in the laboratory and in the field. Plant growth parameters and bacterial colonization of the rhizosphere were determined in both conditions. Differences in root characteristics of twenty three diverse wheat genotypes were observed after growth in the hydroponic system; however responses to inoculation with A. brasilense Sp7 and Sp7-S were variable. In some cases growth parameters were increased and in others they were decreased. There was an apparent increase in responsiveness to inoculation with azospirilla by synthetically derived genotypes observed in root length measurements but otherwise there was no trend according to the genetic source of wheat. Microscopic observations confirmed the different root colonisation patterns by Sp7 and Sp7-S. However, colonisation pattern was not influenced by plant genotype. Relationships between shoot dry weight and root growth parameters were positive as expected but were strengthened with inoculation.

APA, Harvard, Vancouver, ISO, and other styles

4

Mallah, Abdul Nabi. "Effects of water stress and salinity on contrasting wheat genotypes." Thesis, Bangor University, 1991. https://research.bangor.ac.uk/portal/en/theses/effects-of-water-stress-and-salinity-on-contrasting-wheat-genotypes(d16c3b0e-d0a0-44e3-ada1-79fce0bd31ce).html.

Full text

Abstract:

A series of experiments was carried out in the Department of Agriculture, University College of North Wales, Bangor, during October 1987 to September 1989. The purpose of these was to study the effects of water stress and salinity stress at different stages on long (Norman), medium (Fenman) and short duration (Wembley) wheat varieties in different environments. Effects of water stress were tested in large pots in different types of soil. Effects of salinity were tested by growing plants in solution culture. In both experiments water stress and salinity stress were imposed at three major stages, tillering to stem extension (TL-SE), stem extension to booting (SE-BG) and booting to maturity (BG-MT). These were tested in each variety in comparison with a control of each variety. Growth measurements, leaf number and area, stem area, shoot number, plant height, nitrogen %, nitrogen uptake, dry weight per plant were determined at the end of each stage. Soluble carbohydrates were determined at anthesis. This was done to find out how much these growth measurements were decreased during each stress period. Yield and yield components were determined at harvest. In these experiments the long duration variety took a long time in growth during TL-SE, in comparison to mid winter and spring wheat varieties. The long duration variety gave a higher plant, more straw dry weight production and more leaf number than the short duration variety. The long duration variety also gave a higher yield than the medium and short duration varieties, due to larger ears, more spikelets vi per ear, more grain number per ear and more grain number per spikelet. All varieties experienced higher temperatures and longer days during SE-BG and BG-MT in both experiments. The lengths of these stages therefore showed smaller variation between varieties. In water stress experiments the mixed peat-soil used in Experiment 2 dried out quicker than the normal field soil used in Experiment 1. The upper portion of the soil was dried before the lower portion of the soil during the stress period. With water stress at SE-BG and BG-MT the soil dried out quicker in both years. Gypsum blocks were used to give readings of water stress. with water stress at BG-MT the soil was completely dried out after the third week, in all varieties, due to higher plant height, higher temperature and more evaporation. Because of this water stress at BG-MT resulted in a short duration for ripening. In both water stress Experiments 1 and 2, in all varieties all water stress treatments decreased the growth measurements, decreased yield and yield components. In Norman water stress at TL-SE had a long stress period due to slow growth processes during cold winter. However, this stage had a similar effect on yield in Norman, Fenman and Wembley. In both water stress experiments in all varieties, water stress at SE-BG caused the largest reductions in growth measurements, because at this stage the plant had the greatest leaf area and temperature was higher, although the period of stress was only a few weeks. However, water stress at BG-MT caused the greatest decreases in yield. This stage showed the greatest vii decreases in yield and yield components, due to small grain size, fewer fertile spikelets, small size of ear, earlier leaf senescence, short duration for ripening, higher temperature, lack of soluble carbohydrate for grain f~lling from stem and pollination problems at anthesis time. In both salinity Experiments 1 and 2, all varieties had a larger green leaf area, more tillers and all varieties were much stronger after stem extension than in the water stress experiments due to the solution culture teChnique. Norman was more strong than the other varieties because of its long period grown in solution culture. Salinity at TL-SE was more damaging than other stages in all varieties. Salinity at TL-SE decreased the growth measurements, such as leaf area, stem area, plant height, dry weight per plant. Because of the growth measurement reduction, grain weight per plant, grain number per plant, grain number per ear, grain number per fertile spikelet and fertile spikelet per ear were decreased by salinity at this stage. Salinity at SE-BG and BG-MT also decreased growth measurements, decreased grain yield and yield components. Salinity at BG-MT decreased grain yield and yield components more than salinity at SE-BG. In Experiment 2 in all varieties with salinity at BG-MT plants were harvested a few days before other stages and the control. Norman was more sensitive with salinity at TL-SE than the other varieties because of its long period grown under salt stress. Norman was much stronger with salinity at SE-BG. Norman gave lower yield, yield components at BG-MT than other varieties at this stage.

APA, Harvard, Vancouver, ISO, and other styles

5

Ehtaiwesh, Amal Faraj Ahmed. "Effects of salinity and high temperature stress on winter wheat genotypes." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/34545.

Full text

Abstract:

Doctor of Philosophy
Department of Agronomy
P. V. Vara Prasad
Increased ambient temperature and soil salinity seriously affect the productivity of wheat (Triticum aestivum L.) which is an important cereal second to rice as the main human food crop. However, wheat plant is most susceptible to high temperatures and salinity at booting and flowering stages. Several studies have documented the effects of individual stress like salinity and high temperature stress on wheat, nonetheless little is known about effects of combined salinity and high temperature at critical growth stages. Therefore, the objectives of this research were (i) to screen winter wheat germplasm for salinity tolerance at the germination stages and to determine seedling growth traits associated with salinity tolerance, (ii) to evaluate the independent and combined effects of high temperature and salinity on winter wheat genotypes at the booting stages through growth, physiological, biochemical, and yield traits, and (iii) to evaluate the independent and combined effects of high temperature and salinity on winter wheat genotypes at the flowering stages through growth, physiological, biochemical, and yield traits. In the first experiment, 292 winter wheat genotypes (winter wheat germplasm) was screened for salinity stress at germination stage under controlled environments. The seeds were subjected to three levels of salinity, 0, 60, and 120 mM NaCl to quantify the effects of salinity on seed germination and seedling growth. In the second experiment, controlled environment study was conducted to quantity the independent and combined high temperature and salinity stress effects on growth, physiological, biochemical, and yield traits of twelve winter wheat genotypes during booting stage. Plants were grown at 20/15 °C (daytime maximum/nighttime minimum) temperature with 16 h photoperiod. At booting stages, the plants were exposed to optimum (20/15 °C) or high temperature (35/20 °C) and without (0 mM NaCl) and with (60, and 120 mM) NaCl. In the third experiment, plants were exposed to optimum or high temperature and with and without NaCl levels at flowering stages. The temperature regime and salinity levels were same as experiment II. The duration of stress was 10 d and after the stress period the plants were brought to optimum temperature and irrigated with normal water (0 mM NaCl). The results indicated that, at 120 mM NaCl, the final germination percentage was decreased and the mean daily germination was delayed. Irrespective of the genotype, salinity stress significantly decreased the shoot and root length; seedling dry matter production, and seedling vigor. Based on the seedling vigor index, the genotype GAGE, OK04507, MTS0531, TASCOSA, ENDURANCE and GUYMON, were found to be most tolerant and CO04W320, 2174-05, CARSON, OK1070275, TX02A0252 and TX04M410211 were the most susceptible to salinity at germination stage. Combined stresses of high temperature and salinity decreased photosynthetic rate and grain yields. Based on grain yield, the genotype TASCOSA was found to be most tolerant (64 % decrease) to combined stresses, and AVALANCHE was the most susceptible to combined stresses (75 % decrease) at booting stages. Similarly, at flowering stage, TX04M410211 had greater tolerance to combined stresses (65 % decline) as compared to GAGE (83 % decline). In both experiments, tolerance was associated with higher spikelet number and seed set. In conclusion, there is genetic variability among winter wheat genotypes that can be used in breeding programs to improve winter wheat yield under combined high temperature and salinity stress conditions.

APA, Harvard, Vancouver, ISO, and other styles

6

Ali, A. "The effects of environmental stresses on performance of spring wheat genotypes." Thesis, Bangor University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382246.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Honing, Jennifer. "Evaluation and implementation of DNA-based diagnostic methodology to distinguish wheat genotypes." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/638.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Sarvestani, Zeinolabedin Tahmasebi. "Water stress and remobilization of dry matter and nitrogen in wheat and barley genotypes /." Title page, table of contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phs251.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Deng, Lingzhu. "Whole-Wheat Flour Milling and the Effect of Durum Genotypes and Traits on Whole-Wheat Pasta Quality." Diss., North Dakota State University, 2017. https://hdl.handle.net/10365/26737.

Full text

Abstract:

An ultra-centrifugal mill was evaluated by determining the effect of mill configuration and seed conditioning on particle size distribution and quality of whole-wheat (WW) flour. Ultra-centrifugal mill configured with rotor speed of 12,000 rpm, screen aperture of 250 ?m, and seed conditioning moisture of 9% resulted in a fine WW flour where 82% of particles were <150 ?m, starch damage was 5.9%, and flour temperature was below 35?C. The single-pass and multi-pass milling systems were evaluated by comparing the quality of WW flour and the subsequent WW spaghetti they produced. Two single-pass mill configurations for an ultra-centrifugal mill were used (fine grind: 15,000 rpm with 250 ?m mill screen aperture and coarse grind: 12,000 rpm with 1,000 ?m mill screen aperture) to direct grind durum grain or to regrind millstreams from roller milling to make WW flour and WW spaghetti. Particle size, starch damage, and pasting properties were similar for direct fine grind WW flour and multi-pass reconstituted flour:fine bran blend and for direct coarse grind WW flour and multi-pass reconstituted semolina:coarse bran blend. Semolna:fine bran or semolina:coarse bran blends made spaghetti with high cooked firmness, while spaghetti made from direct coarse grind or from semolina:fine bran or coarse bran blends had low cooking loss. Nineteen durum wheat (Triticum turgidum L. var. durum) cultivars and 17 breeding lines grown at 19 environments in North Dakota were evaluated for physical and cooking qualities of WW and traditional spaghetti. Of the 36 genotypes evaluated, 21 and 3 genotypes produced good and poor qualities of WW and traditional spaghettis, respectively, while other 12 genotypes produced good traditional spaghetti but produced poor quality WW spaghetti. These data indicate the need to select genotypes specifically for their WW pasta quality. Raw material traits (grain, semolina and WW flour characteristics) were evaluated to identify raw material traits capable of predicting WW spaghetti quality. Grain protein content had significant positive correlation with cooking quality of WW spaghetti. Stepwise multiple regressions showed grain protein content and mixogram break-time and wet gluten were the predominant characteristics in predicting cooking quality of WW spaghetti.

APA, Harvard, Vancouver, ISO, and other styles

10

Zhang, Yujuan. "Wheat grain Avenin-like protein dynamics in relation to genotypes and environments." Thesis, Zhang, Yujuan (2018) Wheat grain Avenin-like protein dynamics in relation to genotypes and environments. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/43015/.

Full text

Abstract:

The recently discovered non-gluten prolamins, avenin-like proteins (ALPs) in wheat can improve flour baking qualities. In our study, 15 TaALP genes were identified and mapped to chromosomes 7A, 4A and 7D. Phylogenetic analysis showed that TaALP genes formed three major clades, types a, b, and c. The allelic variation of ALP genes in a wild emmer wheat (Triticum turgidum ssp. dicoccoides) populations from Israel were investigated to study the evolution of TdALP genes under different micro environments. In total, 49 alleles were identified at 4 TdALP loci. Correlations between the sites in which wild emmer wheat accessions were collected in Israel and the diversity of their ALP allelles suggested that at least some alleles were selected for by environmental factors. In this project, we found that TaALP genes are pathogen-inducible. Bioinformatics predicted the presence of pathogenesis-related nucleotide motifs in the promoter regions of TaALP genes. Expression levels of TaALP genes and some PR genes were analysed by quantitative RT-PCR in developing caryopses at 7, 13 and 42 days after pollination. Differential expression patterns of TaALP genes were identified in plants infected by Fusarium graminearum. Recombinant TaALP-encoded proteins significantly inhibited the fungal growth in vitro. mRNA in situ hybridization confirmed that TaALP transcripts were upregulated in aleurone, sub-aleurone, and embryos after infection. Genome-wide Fusarium head blight (FHB) index association analysis indicated that certain TaALP alleles were significantly correlated with FHB resistance. The ALPs may act as pathogen resistance proteins mediated by systemic acquired resistance (SAR). Our research indicated that TaALP genes, characterized by typical gliadin domains, are broad-spectrum, partial-resistance genes that contribute to sustainable control of wheat pathogen disease and possibly other fungus-induced disease in wheat. This exciting finding will be applicable for breeding broad range of disease-tolerant and high-quality wheat varieties for sustainable wheat production.

APA, Harvard, Vancouver, ISO, and other styles

11

Day, A. D., and M. R. Elmigri. "Barley Genotypes Grown with Well Irrigation Water on the Safford Agricultural Center." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200513.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Rugg, Mory. "Evaluation of Hard Red and White Spring Wheat Genotypes for Tolerance to Pre-Harvest Sprouting." Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26482.

Full text

Abstract:

Each genotype was exposed to controlled PHS conditions for evaluation of susceptibility or tolerance to sprouting, falling number, kernel color, test weight, and yield. The 24 genotypes were grown in replicated trials at three locations over three years, all data subjected to an analysis of variance. Over three years the genotypes were rated for visual PHS using a 1 to 9 scale, with 1 equivalent to no visual PHS and 9 equivalent to maximum visual PHS. The red genotypes exhibited a higher tolerance to PHS than white genotypes with a mean PHS score of 4.46 compared with 5.16 for white genotypes. Not all the white genotypes were equally susceptible to PHS or more susceptible than the red genotypes, suggesting that not all seed dormancy is linked to the kernel color genes.

APA, Harvard, Vancouver, ISO, and other styles

13

Thompson, Andrew. "The comparative performance of wheat cultivars and genotypes in different organic systems of production." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294863.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Mahar, Abdul Razak. "The comparison of techniques for the development of improved salt-tolerant wheat genotypes." Thesis, Bangor University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266827.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Tunio, Shamsuddin. "Effect on environment and plant growth regulators on the growth of different wheat genotypes." Thesis, Bangor University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293125.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Tjin-Wong-Joe, Andro F. J. "Early grain filling environment and pre-maturity Î±-amylase formation in UK winter wheat genotypes." Thesis, Open University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403839.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Malligan, Cassandra D. "Crown rot (fusarium pseudograminearum) symptom development and pathogen spread in wheat genotypes with varying disease resistance." University of Southern Queensland, Faculty of Sciences, 2009. http://eprints.usq.edu.au/archive/00006225/.

Full text

Abstract:

[Abstract]Crown rot, caused by Fusarium pseudograminearum (Fpg), is an important soilborne disease of wheat and barley. The degree of crop damage depends on seasonal conditions. Typically, high moisture conditions early in the season encourage seedling infection from stubble residues. Moisture stress later in the season leads to the production of unfilled “whiteheads”. Current control relies on cultural practices and sowing of partially resistant varieties. In order to understand the nature of partial resistance, I have examined the patterns of disease symptom development and pathogen spread in susceptible and partially resistant tissues of both pot-grown wheat, barley and oat seedlings and field-grown inoculated wheat trials. Further research was conducted to determine whether differences in pathogenicity occur amongst a small subset of Australian Fpg isolates. Seedling experiments confirmed that differences in disease ratings between susceptible and partially resistant genotypes are detected in younger leaf sheaths of older seedlings. At later harvest times differences between these genotypes are not significant in older leaf sheaths. Re-isolation of Fpg from inoculated seedlings has shown that each tissue was infected later in partially resistant genotypes compared to susceptible ones with a significantly lower number of isolations recorded at each harvest time in 42 day old seedlings. Barley cultivars were rapidly infected by the pathogen and exhibited high levels of disease symptoms. By comparison levels of infection in oats were low compared to all other genotypes. No significant differences between genotypes were observed in coleoptile tissues, either in fungal colonisation or development of disease symptoms. Disease development in the subcrown internode varied between lines/cultivars but was not representative of the relative susceptibility of each genotype. The pathogen did not appear to invade plant tissue via the vascular system but rather spread directly across the stem from leaf sheath to leaf sheath. Field trials were designed to study disease symptom development and localisation of Fpg hyphae in all expanded tissues (excluding head and roots) in wheat genotypes of known susceptibility to crown rot. Plants were harvested at approximately fortnightly intervals throughout the growing season. The main effects and interactions of harvest, genotype and tiller on each plant part were examined with a detailed statistical analysis of differences seen in these factors between susceptible and partially resistant wheat genotypes, in two inoculated field trials. While differences between genotypes were mostly not significant at each harvest when disease rating or isolations from leaf sheath tissues were examined, important differences between susceptible and resistant genotypes were seen in disease developments and Fpg infections of stem tissue in field trials. Restriction of pathogen growth and symptom development was more pronounced in the tissues of 2-49 (possesses seedling resistance) than in the field resistant Sunco. At present, the mechanisms that lead to these resistance responses are unknown. The pathogenicity study aimed to determine whether 7 Fpg isolates and a mixed inoculum differed in ability to cause crown rot in 9 wheat genotypes ranging in susceptibility to this disease. Although a genotype*inoculum interaction was significant, there is no evidence of stable pathogenic races in the isolates examined in these experiments. The growth of all isolates was partially inhibited in a consistent manner on resistant genotypes when compared to very susceptible genotypes. These results confirm significant differences in the aggressiveness of Fpg isolates on wheat, evidenced by variation in mean disease severity between isolates growing on a range of host genotypes.

APA, Harvard, Vancouver, ISO, and other styles

18

Samaan, Jihad. "Characterisation of grain quality of Syrian durum wheat genotypes affecting milling performance and end-use quality." Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/2450.

Full text

Abstract:

Durum wheat is a strategic crop in Syria produced in high quantities and used mainly for the production of Arabic bread, bulgur and pasta. This investigation is the first known systematic study relating the grain quality of nine domestic cultivars to milling performance and pasta quality in order to map the Syrian dururn wheat characteristics onto the world market requirementsa nd henced eterminet he potential export developmentF. urthermore,i t examinest he influenceo f environment,g enotypea nd their interactiono n the physiochemicacl haracteristicso f five dururnw heat cultivars grown in five different locations under rainfed and irrigated conditions in Syria. AACC standardm ethodsw ere principally usedi n this investigation. Despitet he soundnesso f grainsr evealedb y elevatedt est weight (83.1-85.9k ghl*'), 1000k ernel weight (42.50-55.0g ) and falling number (433-597s ec), it is necessary to improve the kernel quality of Syrian durum wheat for the degree of vitreousness and total protein content (average quality data were 65% and 12.6% respectively) for better end-use product quality. In addition, irrigation demonstrated a significant effect on kernel quality traits, for example, irrigated samples showed the highest test weights. The importance of three physiochermical markers, namely total protein content, the degree of vitreousness and kernel hardness was substantiated and presented useful indicators for future development in Syrian durum wheat breeding programmes. Optimum cooking time of pasta and cooked pasta firmness correlated significantly with final viscosity (r = 0.51,0.73), dough development time (r = 0.69 and 0.63) and R., " (r = -0.64, -0.43) which indicated that RVA, farinograph and extensograph techniques were useful indicators of the cooking properties of pasta. Overall, this study revealed that to achieve the aim of improving the domestic production and expanding the potential export of durum wheat crop in Syria, both genetic and agronomic improvements are still required.

APA, Harvard, Vancouver, ISO, and other styles

19

Chappell, Matthew. "Assessment and Reaction of Triticum aestivum Genotypes to Fusarium graminearum and effects on Traits Related to Grain Yield and Seed Quality." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/30784.

Full text

Abstract:

Fusarium graminearum (Schwabe), causal organism of fusarium head blight (FHB), has become a major pathogen of wheat (Triticum aestivum L.) throughout North America. Since its discovery in the United States, the disease has spread south and east until at present it is an annual threat for growers of winter wheat in the Mid-Atlantic region. Yield losses for soft red winter (SRW) wheat averaged 908 kg ha-1 in the FHB outbreak of 1998 (Griffey et al., 1999). The economic loss from this single FHB epidemic was an estimated 8.5 million dollars. Environmental conditions favorable for FHB development, including above average rainfall and temperatures during anthesis, have become more common in the Upper-Midwestern wheat-growing region over the past decade, leading to substantial losses in wheat and barley crops. This, coupled with low prices being paid for wheat, has prompted research toward solving the problem of FHB across the nation. The majority of labor and financial resources devoted to FHB research are dedicated to incorporating FHB resistance into adapted wheat lines. While this is a prudent method of combating this disease, this process will take many years to complete. We have examined all FHB assessment parameters, which include FHB incidence, FHB severity, FHB index, percentage fusarium damaged kernels (percentage FDK), and 15-acetyl deoxynivalenol toxin (DON toxin) accumulation, to ascertain which assessment parameters best quantify FHB resistance levels in addition to grain yield and grain volume weight (GVW) losses. FHB index provides the most reliable in-field assessment of a genotype's resistance level, whereas percentage FDK provides a reliable measure of a genotype's resistance level post-harvest. FHB index and percentage FDK are also the most predictive assessment parameters with regard to grain yield and GVW loss. A wide range in both level and type of resistance was observed among genotypes examined in this study. The cultivars Agripro Patton, Ernie, INW9824, Roane, and the experimental line NY87048W-7388 consistently had lower scores for FHB assessment parameters and lower losses of grain yield and GVW.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

20

Duarte-Delgado, Diana [Verfasser]. "Insights into the salt stress adaptation mechanisms of bread wheat genotypes using a systemic approach / Diana Duarte-Delgado." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/122166932X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Rivera-Amado, Alma Carolina. "Identifying physiological traits to optimize assimilate partitioning and spike fertility for yield potential in wheat (Triticum aestivum L.) genotypes." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32376/.

Full text

Abstract:

Although wheat demand is expected to increase along with a projected growing population, the global rate of wheat yield increase appears to be declining. Genetic progress in yield potential in the past has been achieved mainly through increases in grains m-2 and harvest index with no major changes in above-ground biomass; however, HI has not increased since about 1990 indicating that further increases in yield potential will rely on increases in biomass while optimizing grain DM partitioning. A panel of 26 high biomass CIMMYT elite spring wheat cultivars (CIMMYT Mexico Core Germplasm; CIMCOG) was evaluated for grain yield, above-ground dry-matter (AGDM), DM partitioning and spike fertility in three field experiments (2011, 2012 and 2013) in NW Mexico. An additional field experiment was carried out in 2014 on a subset of four cultivars to examine source-sink related traits by imposing source manipulation treatments (leaf-lamina removal and leaf-sheath shading) on the crop. The main objective was to identify the physiological determinants of grains m-2 and HI in relation to DM partitioning among organs and to prioritise traits for application in breeding to increase HI in high biomass genotypes. Genetic variation in grain yield among genotypes was explained mainly by differences in AGDM. Fruiting efficiency (grains per unit spike DM at anthesis) was affected by high rachis specific weight and appeared to be important in grains m-2 determination. Trends for positive associations were observed between HI and spike partitioning index (Spike DM / AGDM - at anthesis; SPI). Stem DM proportion (mainly structural DM in internodes 2 and 3) was negatively associated with SPI; peduncle length and peduncle DM as a proportion of the stem DM on the other hand were more strongly associated to spike DM per unit area. In 2014, reductions in final grain weight in response to source reduction treatments were relatively low compared to the estimated reductions in light interception. No up-regulation of photosynthesis rate was observed by the flag-leaf or the spike in response to source reductions, suggesting that grain growth was overall sink limited but close to a co-limitation by source and sink. These results indicated scope for designing a plant ideotype to raise HI in high biomass spring wheat cultivars with reductions in stem structural DM (in upper internodes) without major effects on water soluble carbohydrate accumulation (in lower internodes). Finally, results from the source-sink manipulation treatments indicated limited scope for reductions in leaf-sheath and lamina DM partitioning during stem elongation to favour spike growth.

APA, Harvard, Vancouver, ISO, and other styles

22

Bakhshandeh, Shiva. "Effect of Climate Change and Soil Management on Water and Nutrient Uptake for Sustainable Yield of Wheat Genotypes with Different Root Traits." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18649.

Full text

Abstract:

Drought and heat stress are the most important climate change factors decrease water and nutrient uptake and therefore negatively affect wheat growth. Surface soil drying decreased both water and NH4+ uptake from the top soil. However, increased water availability with bottom watering increased water uptake from the bottom soil layer, but not NH4+ uptake from the bottom soil layer. With surface soil drying, plants grew more and longer roots in the bottom soil layer, shifting water uptake from the top to the bottom soil, while N uptake was reduced in the top soil because of a decrease in root biomass. Drought stress and heat stress decreased the yield of all wheat genotypes, in particular 249, while combined drought and heat stresses had the most pronounced negative effect on plant biomass and grain yield. Decreasing soil water availability decreased plant-derived C to soil organic carbon (SOC) and microbial biomass through rhizodeposition. Wheat genotypes with smaller root/shoot ratios and thinner roots were more efficiently assimilating C to the grain, while genotypes with higher root/shoot ratios and thicker roots allocated more C belowground through rhizodeposition at the expense of producing more yield. Increasing water availability from 15 % to 25% and reducing air temperature 30 to 25 °C increased N uptake by plants thereby reducing overall N loss, and increased transfer of N from vegetative parts to grain. While crop rotation did not affect soil available N and P, AMF colonization in wheat was on average 60% higher after chickpea than after the canola rotation. Wheat yield after chickpea increased for genotype IAW2013, and was positively related to AMF colonization for both genotypes. N and P fertilization reduced AMF colonization and yield, but increased shoot biomass and leaf tissue N and P concentrations. Leaf δ13C decreased with increased yield, suggesting that higher yielding and AMF colonized plants were less water stressed.

APA, Harvard, Vancouver, ISO, and other styles

23

Trujillo, Negrellos Eliseo. "Identify physiological traits to increase yield potential through enhanced biomass, spike fertility and optimized source-sink balance in wheat (Triticum aestivum L.) genotypes." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31200/.

Full text

Abstract:

Increased demand for food, climate change and greater dependence on food imports in less developed countries represent a challenge to achieve global food security. Wheat (Triticum aestivum L.) is the most widely grown crop and an essential component in ensuring global food security. Therefore, breeders need to develop new cultivars with higher grain yield potential. One physiological avenue to raise yield potential is by improving the allocation of assimilate to the spike during stem elongation to enhance grains m-2 and harvest index (proportion of above-ground dry matter at harvest in grain; HI). Partitioning to spikes could be increased to enhance floret survival by reducing competition from alternative sinks, including roots, leaves, stems and infertile tillers (Foulkes et al., 2011). However, attention must also be paid to maintaining post-anthesis source (photosynthetic capacity) to ensure grain growth of new cultivars is not source-limited. Although yield grains in wheat have historically been associated with traits influencing the capacity of the grains to store assimilate (sink), rather than influencing potential assimilate production (source), there is some evidence that modern cultivars are moving closer towards source limitation of grain growth (Acreche and Slafer 2009). So it is important to quantify the source and sink balance in CIMMYT elite germplasm and its physiological determinants to guide further strategies for yield potential improvement. The objectives of this study were to: i) Identify physiological traits determining enhanced above-ground biomass per unit area and radiation-use-efficiency (above-ground biomass per unit photosynthetically active radiation (PAR) interception; RUEPAR), spike fertility and HI in modern high biomass CIMMYT spring wheat germplasm, ii) quantify post-anthesis source: sink balance according to responses to a degraining to source-sink manipulation treatment, and iii) identify marker-trait associations for grain weight response to degraining (as an indication of source-sink balance) and senescence-related traits. In this study, a panel of twenty six elite CIMMYT spring wheat cultivars and a wheat association mapping (WAMI) panel of 294 genotypes comprising advanced lines and cultivars were evaluated in replicated field experiments under full irrigation in NW Mexico. The 26 cultivar panel was grown in in three seasons (2010-11, 2011-12 and 2012-13) and the WAMI panel in two seasons (2012-13 and 2013-14). In the 26 cultivar panel, growth analysis was carried at key development stages to assess above-ground dry matter (AGDM), DM partitioning and green canopy area. Assessment of fractional PAR interception by the canopy was carried out during the stem-elongation phase (GS31-GS65+7d) and RUEPAR was calculated over this phase in 2011-12 and 2012-13. Flag-leaf stomatal conductance was measured at around anthesis and senescence parameters were assessed at the canopy level and at leaf level. In both the 26 cultivar panel and the WAMI panel experiments, a degraining treatment was carried out at anthesis (GS65) +7-14 days by removing half of the spikelets to assess grain weight responses compared to control spikes as an indicator of source-sink balance and leaf and canopy senescence parameters were quantified in the control treatment. In the 26 cultivar panel, grain yield variation was associated more strongly with AGDM at harvest than HI; and biomass was positively associated with year of release. Radiation-use efficiency during stem elongation (GS61 – GS65+7d) showed genetic variation in one year out of two in which this trait was measured and a positive association with crop growth rate (AGDM g m-2 d-1) and with flag-leaf nitrogen (N) content. Furthermore, both flag-leaf stomatal conductance at anthesis and RUEPAR showed a positive association with grain yield among the 26 cultivars. There was genetic variation in each of spike partitioning index (proportion of AGDM as spike at GS65+7d) and fruiting efficiency (grain per g spike DM at GS61+7d) positively associated with grains m-2 amongst the 26 genotypes, and there was no trade-off between SPI and FE. Fruiting efficiency was associated with a greater proportion of lemma DM within the spike morphological components (glume, rachis, lemma, palea and awn). Results showed there is scope to increase biomass through RUEPAR and RUEPAR could be enhanced by selecting for increased stomatal conductance and/or flag-leaf N content. Grain weight responses to the degraining treatment in both the 26 cultivar panel and the WAMI panel showed that grain growth was either sink limited or co-limited by sink and source in the genotypes. In both panels, genotypes with higher grain yield showed higher grain weight responses to degraining (indicating a greater extent of source limitation); and greater grain weight responses were associated with faster senescence rate, supporting a co-limitation of source and sink in modern high yielding CIMMYT spring wheat cultivars. The genetic association mapping analysis identified a marker-trait association for grain weight response to degraining (an indicator of source-sink balance) on chromosome 7A in the WAMI panel. Grain m-2 was not associated with grain yield indicating that grain weight at some extent is driving gains to grain yield due to its positive association with year of release. Grain yield positively correlated with response to degraining over years, grain weight response to degraining was negatively associated with Flag leaf senescence in the WAMI population. Genetic variation in radiation interception by the canopy during stem elongation from GS31 to GS65+7d positively associated with accumulated above-ground dry matter amongst the CIMCOG genotypes. There was genetic variation in radiation-use efficiency (in 2013) during stem elongation and RUE was positively related with above-ground biomass at anthesis amongst the CIMCOG genotypes. Therefore, in order to increase grain yield is necessary to increase simultaneously source and sink traits.

APA, Harvard, Vancouver, ISO, and other styles

24

Salomon, Marcus Vinicius. "Trigo: avaliação de linhagens diaplóides obtidas via cultura de anteras." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-12082002-140835/.

Full text

Abstract:

Avaliaram-se 36 linhagens diaplóides de trigo, obtidas via cultura de anteras in vitro oriundas de plantas híbridas, em geração F1, divididas em dois ensaios com dezoito linhagens e dois cultivares controles (IAC-24 e IAC-289), nos anos de 1999 e 2000. Cada ensaio foi instalado em dois locais do Estado de São Paulo: Ensaio I - Estações Experimentais de Agronomia de Capão Bonito (solo ácido, sem aplicação de calcário e em condição de sequeiro) e Tatuí (solo ácido, com aplicação de calcário e em condição de irrigação por aspersão) e Ensaio II - Estações Experimentais de Agronomia de Tatuí e Monte Alegre do Sul (ambos em solo ácido com aplicação de calcário e condição de irrigação por aspersão). Em cada ensaio, avaliaram-se os seguintes parâmetros: acamamento, altura da planta, ciclos da emergência ao florescimento e da emergência à maturação, produção de grãos, resistência às moléstias, comprimento da espiga e componentes de produção. Todos os genótipos foram, também, avaliados quanto à tolerância à toxicidade de alumínio, em solução nutritiva, em condição de laboratório. No Ensaio I, destacaram-se, pela produção de grãos, as linhagens 4 (2.309 kg ha -1 ) e 5 (2.319 kg ha -1 ), provenientes do cruzamento PF70402/ALD'S'//PAT72160/ALD'S'/3/PEW'S'/4/OPATA/5/IAC-60; 9 (2.150 kg ha -1 ), provinda do cruzamento MLR'S'/BUC'S'//BUC'S'/3/IAC-24, 11 (2.102 kg ha -1 ) e 12 (2.056 kg ha -1 ), oriundas do cruzamento TEPOCA/IAC-24. A 13 (JUN/GEN//IAC-24) apresentou as plantas mais baixas (53 cm). As linhagens 2, 4 e 18, originárias dos cruzamentos JUN/GEN//IAC-24,PF70402/ALD'S'//PAT72160/ALD'S'/3/PEW'S'/4/OPATA/5/IAC-60 e TEPOCA/IAC-24, revelaram, ao mesmo tempo, moderada resistência aos agentes causais da ferrugem-da-folha e da mancha-da-folha. Todos os genótipos, com exceção do cultivar IAC-289 e da linhagem 13 (JUN/GEN//IAC-24), foram considerados tolerantes a 10 mg L -1 de Al 3+ , quando avaliados em solução nutritiva. No Ensaio II, a linhagem 8 (ANA/IAC-24) e o cultivar IAC-289 apresentaram elevadas produções de grão (3.311 e 3.341 kg ha -1 respectivamente). A linhagem 13 exibiu o porte mais baixo (61 cm) entre os genótipos estudados e a 3 (ANA/IAC-24//IAC-24), mostruo, ao mesmo tempo, resistência ao agente causal da ferrugem-da-folha, moderada resistência ao agente da mancha-da-folha e imunidade ao agente causal do oídio. As linhagens 8 (ANA/IAC-24) e 14 (PF70402/ALDS//PAT72160/ ALDS/3/PEWS/4/OPATA/5/ IAC-60) mostraram elevada tolerância à toxicidade de alumínio, associada a alta produção de grãos.
Thirty six dihaploid wheat lines, originated via anther culture from F1 hybrid plants were evaluated in two trials with eighteen lines plus two control cultivars (IAC-24 and IAC-289), in 1999 and 2000. Each trial was carried out in two locations of the State of São Paulo: trial I - Capão Bonito Agronomy Experiment Station (acid soil without lime application and upland condition) and Tatuí Agronomy Experiment Station (acid soil with lime application and sprinkler irrigation condition) and trial II - Monte Alegre do Sul and Tatuí Agronomy Experiment Station (both with acid soil with lime application and sprinkler irrigation condition). In each the genotypes were evaluated for lodging, plant height, cycle from emergence to flowering and from emergence to maturation, grain yield, resistance to disease, head length and yield components. All genotypes were also evaluated for aluminum toxicity tolerance, in nutrient solution, under laboratory condition. Considering trail I, the lines 4 (2.309 kg ha -1 ) and 5 (2.319 kg ha -1 ) originated from the cross PF70402/ALD'S'//PAT72160/ALD'S'/3/PEW'S'/4/OPATA/5/IAC-60, 9 (2.150 kg ha -1 ) from the cross MLR'S'/BUC'S'//BUC'S'/3/IAC-24, and the lines 11 (2.102 kg ha -1 ) e 12 (2.056 kg ha -1 ) from the cross TEPOCA/IAC-24, presented high grain yield. The line 13 (JUN/GEN//IAC-24) showed the shortest plants (53 cm). The lines 2, 4 and 18 originated from crosses JUN/GEN//IAC-24,PF70402/ALD'S'//PAT72160/ALD'S'/3/PEW'S'/4/OPATA/5/IAC-60 and TEPOCA/IAC-24, showed at the same time moderate resistance to the causal agents of leaf rust and leaf spot. All genotypes, with exception of the cultivar IAC-289 and the line 13 (JUN/GEN//IAC-24) , were considered tolerant to 10 mg L -1 Al 3+ , when evaluated in nutrient solutions. Considering trial II, the line 8 (ANA/IAC-24) and the cultivar IAC-289 presented high grain yield (3.311 e 3.341 kg ha -1 respectively). The line 3 (ANA/IAC-24//IAC-24) exhibited at the same time resistance to the causal agent of leaf rust, moderate resistance to the causal agent of leaf spot and immunity to the causal agent of powdery mildew. The lines 8 (ANA/IAC-24) and 14 (PF70402/ALDS//PAT72160/ALDS/3/PEWS/4/OPATA/5/IAC-60), also showed high tolerance to aluminum toxicity being associated to high grain yield, and so could be used in breeding programs with the objective to get cultivars for acid soils.

APA, Harvard, Vancouver, ISO, and other styles

25

Sala, Valeria Marino Rodrigues. "Resposta da cultura do trigo aos novos endófitos, Achromobacter e Zoogloea, em condições de campo." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-10042007-161807/.

Full text

Abstract:

Este é o primeiro relato da presença de bactérias diazotróficas dos gêneros Achromobacter e Zoogloea como endófitas de plantas de trigo, que foram identificadas pela análise das seqüências do DNA ribossomal 16S. Com o objetivo de estudar a localização dos isolados: IAC-AT-8- Azospirillum brasiliense, IAC-HT-11- Achromobacter insolitus, IAC-HT-12- Zoogloea ramigera nas plantas de trigo, foi realizado um experimento em condições axênicas. Após 15 dias da inoculação, as plantas foram observadas em microscópio eletrônico e visualizou-se a presença das bactérias externamente nas raízes e internamente no córtex, na região de alongamento. Para estudar possíveis benefícios propiciados por estes isolados à cultura do trigo em condições de campo, foram instalados dois experimentos no ano de 2002, com dois genótipos de trigo (ITD-19 e IAC-370) e três doses de N. As análises foram realizadas no estádio de quatro folhas e de perfilhamento. A inoculação promoveu maior massa de matéria seca e N acumulado e aumentou a produtividade de grãos, principalmente na presença de adubo nitrogenado adicional, porém, revertendo em lucro para o agricultor. As respostas variaram em relação ao local de cultivo. Em 2003, foi realizado outro experimento muito semelhante aos anteriores, entretanto, as análises foram realizadas no estádio perfilhamento e de maturidade fisiológica. A inoculação promoveu benefícios à cultura do trigo independentemente do genótipo utilizado, ou seja, aumento do N acumulado no grão, com a inoculação do isolado IAC-AT-8, e da produtividade de grãos na maior dose de N, com o isolado IACHT- 11. Os benefícios propiciados às plantas pela inoculação de bactérias diazotróficas podem estar relacionados à capacidade de síntese de fitormônios. Por isso instalou-se um experimento no ano de 2005 com o objetivo de relacionar a capacidade de síntese de indóis com os possíveis benefícios à cultura do trigo em condições de campo. Os isolados diferiram quanto a quantidade de indóis que sintetizaram, entretanto, houve benefícios para a cultura, principalmente com a adição de adubo nitrogenado, demonstrando que outros mecanismos podem ser responsáveis pelas respostas positivas. Assim, foi realizado um experimento em casa de vegetação para estudar a influência da inoculação no metabolismo do nitrogênio das plantas e avaliar a colonização em substrato não esterilizado. Os isolados foram marcados com resistência a antibióticos. Após 40 dias da inoculação todos os isolados estavam presentes no interior das raízes, entretanto, não foram detectados no solo. O isolado IAC-HT-11, influenciou o metabolismo do nitrogênio das plantas, propiciando maior atividade das enzimas redutase do nitrato e sintetase da glutamina, e maior teor de clorofila, resultando no aumento da eficiência de utilização do N. Apesar das respostas terem sido variáveis, em todos os experimentos realizados foram obtidas respostas positivas à inoculação do isolado IAC-HT-11 de Achromobacter insolitus, na presença de adubo nitrogenado adicionado. A inoculação é uma prática não onerosa, portanto, viável economicamente, aumentando a produtividade de grãos e gerando lucro para o agricultor.
This study reports for the first time the endophytic nature of Achromobacter and Zoogloea in wheat plants, that were identified by 16S rDNA gene sequence analyses. To find out the localization of the bacterial cells (IAC-AT-8- Azospirillum brasiliense, IACHT- 11- Achromobacter insolitus, IAC-HT-12- Zoogloea ramigera) in/on wheat plants, an experiment was set up under axenic conditions. Fifteen days after inoculation, the plants were observed under electron microscope. All the strains could be visualized on the external part of the root and in the inner part at the elongation zone, in the cortex cells. Two field experiments were carried out in year of 2002, with the aim of evaluating the benefits from inoculation of these strains in wheat plants, with two wheat genotypes (ITD-19 and IAC-370) and three levels of nitrogen fertilizer. The plants were evaluated at four leaves and at tillering stage. Inoculated plants presented increases in dry matter, N accumulation and grain yield, especially in combination with N fertilizer, generating financial profits for the farmer. The responses to inoculation varied according to the location. A field experiment was carried out, in year of 2003, with the same experimental set up used at the previous year. However, the plants were evaluated at tillering stage and at maturity stage. Grain yield and the main yield components were evaluated at harvest. Independent of the cultivar or the nitrogen dose, plants inoculated with the strain IAC-AT-8 presented increases in grain N accumulation and, at the highest nitrogen dose, the strain IAC-HT-11 increased grain yield. The plants? benefits due to the inoculation of endophytic diazotrophic bacteria may also result from their indole synthesis, a field experiment was carried out to find out which had been the main mechanisms for improvement of plant growth and yield, in 2005. The employed strains produced variable amounts of indoles, however, the inoculation brought benefits to wheat plants, mainly in the presence of added N, demonstrated that others mecanisms could be acting for the positive responses to inoculation. In this way, a greenhouse experiment was carried out with the aim of evaluating the influence of inoculation on nitrogen metabolism in wheat plants, and the colonization in unsterilized substratum. The strains were selectively market with antibiotic resistence to. Forty days after inoculation, all three strains had been established in the interior of the roots, however, they could not be detected in the soil. The strain IAC-HT-11 influenced the N metabolism of the plants, increased the nitrate reductase and glutamine synthetase activities, and the chlorophyll content, causing higher efficiency in N utilization. In spite of the great variability of the inoculation response, IAC-HT-11, Achromobacter insolitus, generated the greatest yield increase when combined with nitrogen fertilizer. Inoculation of diazotrophic bacteria is an inexpensive technique, that is economically sound, promoting the increase in grain yield and generating financial profits for the farmer.

APA, Harvard, Vancouver, ISO, and other styles

26

Saville, Robert Jack. "Understanding DELLA in wheat : linking genotype to phenotype." Thesis, University of East Anglia, 2011. https://ueaeprints.uea.ac.uk/32675/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Roozeboom, Kraig Lyle. "Testing wheat in Kansas : genotype, environment, and interaction effects /." Search for this dissertation online, 2006. http://wwwlib.umi.com/cr/ksu/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Mattioni, Bruna. "Effect of wheat processing and genotype on the gluten proteins." reponame:Repositório Institucional da UFSC, 2017. https://repositorio.ufsc.br/xmlui/handle/123456789/177880.

Full text

Abstract:

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Ciência dos Alimentos, Florianópolis, 2017.
Made available in DSpace on 2017-08-01T04:15:06Z (GMT). No. of bitstreams: 1 348596.pdf: 2480210 bytes, checksum: 254174b55dd985fe8496c68ad4b4058e (MD5) Previous issue date: 2017
Abstract : Wheat is worldwide utilized as a food grain since the late Stone Age and cultivated since 5000 b.c.. From wheat flour a diversity of baked products can be made because the unique ability of form a viscoelastic dough, characteristic controlled mainly by gluten proteins. Gluten proteins are among the most complex protein networks in nature due to numerous different components and distinct size, and due to variability caused by genotype, growing conditions and technological processes. On the other hand, Celiac disease (CD), the most common wheat intolerance worldwide, is a complex immune-mediated disease trigged by gluten ingestion. Assume a strictly gluten-free diet represents the only effective medical treatment for CD patients. On the other hand, treatments that involve time, temperature and pressure can change protein structure. The heat treatments can affect technological properties and reduce the allergenicity to varying extents in wheat flours and breads. Also, nowadays, there is growing interest in ancient wheats, such as einkorn, emmer, Khorasan (Kamut), faro, and spelt because might these varieties could be nontoxic to celiac and helthier than modern wheat. The aim of this project was to study the effect of wheat treatment and the different varieties of wheat on the gluten proteins and the implications in the immune response in vitro. This work was divided in 3 parts. I ? Brazilian commercial wheat flour was subjected to to spray drying, oven heating, ultrasound and microwave radiation. Solubility, monomeric and polymeric proteins and glutenin and gliadin profile were analyzed. Also, digestibility and the amount of potential celiac disease immune stimulatory epitopes were measured with the R5 monoclonal antibody and G12 ELISA assays. Heat treatment leads to unfolding of peptide chains, changes in hydrophobicity and susceptibility to the action of proteolytic enzymes. The treatments affected solubility, and with exception of ultrasound, all treatment showed low solubility of polymercis and monomerics proteins. Also, treatments affected glutenins and gliadins profile, the amount of the HMW-GS (High Molecular Weigh ? glutenin) decrease after spray-dry, oven and extrusion and the amount of the LMW-GS (Low Molecular Weigh ? glutenin) decrease too after spray-drying, microwave, oven and extrusion. Wheareas for gliadin, the amount of ?-gliadin increase after spra-drying and ultrasound treatments, and the amount of a/ß- gliadin decrease after all treatments, while the treatment to do not affected ?-gliadins amount. Also, digestibility decrease after spray-dryier and ultrasound. This changes with decrease of solubility and changes in profile of proteins is results of rearrange of proteins during the treatments, resulting in a higher complex structure. And, finally, the potential celiac disease immune stimulatory epitopes were measured, and showed lower amount after spray-drying treatment by R5 monoclonal antibody and lower amounts after spray-drying and microwave treatment by G12 ELISA test in relation to control flour. At last, even with the alteration on the gluten structure and complexicity, these changes do not allow to produce a safe product to celiacs, the amount of the potential celiac disease immune stimulatory epitopes still were too high. II ? Modern and ancients? wheat varieties are being tested against anti-Gliadin antibody. If aim to found a wheat nontoxic to celiacs, we tested pools of different wheats varieties, two of them with AA genome - T. monococcum ssp monococcum and T. urartu. Due agronomical caracteristic and comercial appeal, we used five T. turgidum wheat variety as follow: T. turgidum ssp durum (AABB), T. turgidum ssp polonicum (AABB), T. turgidum ssp turgidum (AABB) and T. turgidum ssp turanicum (AABB). All wheat flours were extracted, purified, separated using 2D gel eletrophoresis, stained with Comassie blue or were run a western blot with Gliadin antibody and Skeritt antibodies, and pictures of them were overlapping. All wheat varieties tested contained gluten proteins recognized by anti-gluten Skerritt and Gliadin antibodies related to T-cell stimulatory epitopes, at distinct levels. Einkorn and durum species tested here differ in toxicity depending on the sub-species. Eikorn tested showed higher immunogenicity that durum varaities. So, it is not safe for all celiacs to consume the wheat varieties tested, that include ancients? varieties. III - Additionally, this study verified if food products commercialized in Brazil were correctly labeled in relation to the presence or absence of gluten by using the ELISA R5 method. In relation to products sold in Brazil, the results show for the celiac population that companies are testing their food products to verify if labeling is correct to provide products that are safe and to accurately identify potential gluten levels. However, if 89% of gluten-free food products are correctly labeled, this means that 11% represent a risk for the health of the celiac population. To improve this amount, routine auditing is necessary to verify the correct labeling about gluten in food products and adopt good manufacturing practices. Brazil is becoming a global economic player, so it is important to be aligned with global legislation concerning gluten presence and ensure that the label can be trusted. This results in greater confidence in both the global market and consumers and represents one more step toward health maintenance for celiacs.

Introdução: O glúten é uma proteína encontrada nos grãos de trigo, centeio e cevada. Neste trabalho, considerar-se-á o trigo como a fonte de glúten, pelo fato desta matéria prima ser amplamente utilizada tecnologicamente no mundo, em pães, biscoitos, bolos e massas. Se, por um lado o consumo de pães é tido não somente como uma questão cultural, mas também religiosa através do mundo e do tempo, por outro lado, atualmente há discussões sobre o consumo de glúten. A adoção e indicação de dietas sem glúten, mesmo para quem não apresenta sintomas clínicos e fisiológicos de uma intolerância alimentar levou a Sociedade Brasileira de Alimentação e Nutrição a publicar um artigo sobre o posicionamento da mesma, esclarescendo que dietas sem glúten devem ser recomendadas apenas para indivíduos com alguma desordens relacionada ao glúten. Por outro lado, com esse debate, os casos de indivíduos que apresentam alguma disfunção ao ingerirem glúten, são mais facilmente identificados. Atualmente, o unico tratamento é a adoção de uma dieta sem gluten. Ainda hoje, o diagnóstico pode demorar, pois os sintomas podem ser diferentes de indivíduo para indivíduo, além disso, os sintomas se sobrepoem aos de outras doenças, o que leva médicos a investigarem outras doenças. Para facilitar o entendimento, diagnóstico e classificação, as desordens relacionadas ao glúten foram recentemente classificadas de acordo com a resposta em: autoimune, alérgica e de sensibilidade. Sendo que o presente trabalho é focado nas respostas autoumines provocadas pela ingestão de glúten, que são a doença celíaca, ataxia provocada pelo glúten e dermatite herpetiforme. A indentificação destas se dá por teste clínicos (sintomas), histológicos (danos no intestino), sorológicos (presença no soro dos anticorpos anti-gliadina, anti-endeomisio e anti- transglutaminase) e genéticos (presença dos genes DQ 2/8). Acredita-se que no Brasil dois milhões de indivíduos são celíacos ou possuem alguma desordem relacionada ao gluten. Como o único tratamento é a exclusão do glúten da dieta, acaba movimentado um mercado de produtos alimentícios sem glúten. No Brasil, o número de empresas de alimentos que comercilizam produtos sem glúten e o volume de vendas tem aumentando exponencialmente. Nos Estados Unidos, o mercado de produtos sem glúten movimentou 8,8 bilhões de dólares até 2014. Devido à importância econômica do trigo em nível nacional e mundial, fazem-se necessários mais estudos, não apenas em relação à doença celíaca, mas também em relação ao glúten de trigo e suas variedades, e como o tratamento térmico deste cereal, pode afetar ou influenciar na resposta imune de indivíduos com pré disposição genética. Além disso, surgem especulações sobre o consumo de trigo de diferentes variedades, as quais poderiam ser não ser tóxicas, umas vez que não passaram por tantos processos de hibridização e manipulação gênica como o trigo hexaplóide moderno. Objetivos: O principal objetivo deste trabalho foi estudar o efeito do tratamento térmico do trigo e as diferentes variedades de trigo sobre as proteínas do glúten e quais as implicações na resposta imune in vitro. Neste contexto, os seguintes objetivos específicos foram estabelecidos: Submeter farinha brasileira comercial aos tratamentos de extrusão, spray-dry, ultrassom, microondas e forneamento. Analisar as alterações em relação as características tecnológicas das proteínas que formam o glúten na farinha do trigo antes e após os tratamentos quanto à: solubilidade, proporção entre proteínas monoméricas e poliméricas, perfil de gliadinas e gluteninas. Analisar se houve aumento ou diminuição da digetibilidade, e se os tratamentos térmicos afetam a quantidade de epitopos estimuladores de células T em celíacos pelo teste de ELISA R5 e G12. Obter e analisar diferentes variedades de trigo sendo elas: Triticum monococcum ssp monococcum, Triticum urartu, Triticum turgidum ssp durum, Triticum turgidum ssp polonicum, Triticum turgidum ssp turgidum, Triticum turgidum ssp turanicum, Triticum aestivium ssp spelta. Analisar se houve diferença entre as variedades na quantidade de epitopos estimuladores de células T em celíacos in vitro, usando western blott e anticorpos comerciais específicos. Verificar se os produtos ?sem glúten? comercializados no Brasil estão corretamente rotulados.

APA, Harvard, Vancouver, ISO, and other styles

29

Al-Fadly, Molook. "Genotype and environmental influences on grain quality characteristics of Australian wheat varieties." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/11817.

Full text

Abstract:

Variability of quality parameters between Australian wheat varieties grown in different locations and seasons causes difficulties in delivering uniform grains with consistent quality to local and international markets and in predicting functional performance in food processing and human nutrition. The objective of this thesis is to assess the relative contributions of genotype (cultivar), environment and their interactions to variability of quality traits such as test weight, grain protein content, β-glucan, fructans, total starch content, total arabinoxylans (T-AX), water extractable arabinoxylans (WE-AX), water un-extractable arabinoxylans (WU-AX), free, conjugated, bound and total phenolic acids. Three commercial Australian wheat (Triticum aestivum L.) varieties (Gregory, Janz and Peake) grown in 13 different geographic regions of Australia were used to examine wheat whole meal quality parameters. The grain samples were obtained from the National Variety Trials (NVT) conducted by the Australian Grains Research and Development Corporation (GRDC). Total starch, fructans, β-glucan and total T-AX were determined using Megazyme assay kits (Spectrophotometric analysis), arabinoxylan fractions were analysed using a spectrophotometric technique based on the orcinol-HCl method. Phenolic acid fractions were extracted using liquid nitrogen and analysed using a spectrophotometric technique based on Folin-Ciocalteau reagent and by high pressure liquid chromatography (HPLC) with measurements being made for individual phenolic acids in each fraction. Grain protein content and test weight were provided by NVT. The functionality of hard, soft and waxy wheat starch varieties, with and without the additions of WE-AX, was studied by a series of tests including thermal properties using Differential Scanning Calorimetry (DSC) and pasting properties using the Rapid Visco Analyser (RVA). All parameters measured and meteorological factors before and after flowering (temperature, rainfall and daily solar exposure) were analysed by statistical methods to deduce which factors influenced grain quality characteristics. The soil characteristics and fertilizers used were not available for all the locations, and because of the large number of missing values which could potentially bias the results of the correlation and regression analysis, these factors were not included in the analysis. Variability of the quality traits and starch functionality was described in terms of the influence of genotype, environmental factors and their interactions. This study showed that genotype contributed significantly to variability of all the traits tested. Genotype strongly influenced T-AX and WU-AX. Arabinoxylans levels were shown to vary among wheat genotypes. The average ratio of arabinose to xylose was 0.6 for each of the three varieties and this might indicate similarities of the substitution pattern of the xylose backbone by arabinose residues of the three cultivars. Growth environment was the main contributor to the variability of total starch, grain protein, WE-AX, β-glucan and test weight. Growing conditions had strong significant correlations (α = 0.01 and α = 0.001) with wheat grain protein, total starch, WE-AX, fructans and test weight. Growth conditions had moderately significant correlations (α = 0.05) with T-AX and WU-AX, while variability in WE-AX had an inverse and stronger correlations (α = 0.01 or α = 0.001) with the growing conditions compared to total AX and WU-AX. Arabinoxylan fractions (WE-AX and WU-AX) differed in solubility and in their variability due to environmental factors. These differences might be related to their different molecular weights, the incomplete cross-linking of WE-AX with other components, and to the loose binding of WE-AX to the cell wall surface. Genotype influenced all of the pasting properties of Gregory, Janz and Peake starches. The effects of growth conditions on starch pasting properties were significant on peak, breakdown and setback viscosities and pasting temperatures. Environmental temperature (minimum temperature days at < 0 ̊C) had negative correlations with pasting viscosities whereas total rainfall and average rainfall after flowering had positive correlations with setback viscosity. With regards to the addition of WE-AX to several wheat starches (Kukri, QAL2000 and QA-WX-83), the RVA pasting viscosities (peak, trough, final and setback) were decreased, whereas the DSC onset and peak temperatures were increased, but the change in enthalpy was decreased. The pasting and the thermal profiles of Kukri, QAL2000, and QA-WX-83 with WE-AX, have shown that WE-AX compete with starch granules for water. This study showed that phenolic acids are very variable compounds. The contents of free, conjugated, bound and total phenolic acids of whole meal flour from the same cultivar (Gregory, Janz and Peake) were different between locations and seasons. Cultivar was the main factor influencing free and bound phenolics of Gregory, Janz and Peake samples, which were grown in the 2010 season. Interactions between the genotype and the environment contributed strongly to conjugated and total phenolics. However, when two seasons were involved (2010 and 2012), genotype and all environmental factors had significant contributions to variability of soluble, conjugated, bound and total phenolic acids of Gregory and Janz samples (Peake was not planted in the 2012 season). Gregory cultivar had the highest amount of total phenolics in 2010 and 2012 seasons and its pattern did not change over the two seasons (the mean free phenolic concentrations tended to be consistently higher than bound and conjugated phenolics). Weather conditions in the 2010 season (average temperature before flowering, rainfall and solar exposure before and after flowering) influenced strongly conjugated and total phenolics. Weather conditions influenced all of the phenolic acids in the two seasons involved, 2010 and 2012. Benzoic acid derivatives (C6-C1) and cinnamic acid derivatives (C6-C3) followed different trends. The conjugated, bound, and free forms of 4-hydroxybenzoic acid, vanillic acid, syringic acid and sinapic acid all followed a similar trend with respect to growth location. The concentrations were highest in the conjugated form, less in the bound form, and least in the free form at all seven locations. On the other hand, the conjugated, bound, and free forms of p-coumaric acid, caffeic acid and ferulic acid followed a consistently different trend to the other four phenolic acids with respect to location. The concentrations were highest in the bound form, less in the conjugated form, and least in the free form at all seven locations. In conclusion, this study showed that genotype, environment and their interactions influenced grain quality parameters. Both genotype and environmental factors influenced pasting properties of starch. Genotype was the main influencing factor to the variability of T-AX and WU-AX. WE-AX competed with Kukri, QAL2000 and QA-WX-83 starches for water and influenced RVA and DSC parameters. Genotype and all environmental factors contributed significantly to the variability of phenolic acids in wholemeal flour.

APA, Harvard, Vancouver, ISO, and other styles

30

Giles, Tom. "Gene regulatory networks for wheat genotype-dependent effects of cold temperatures." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576493.

Full text

Abstract:

Understanding and optimising the response of crops to climate change is of central importance in enhancing food security. A better understanding of how wheat genes influence traits is required to allow breeders to respond to socioeconomic issues. One aspect concerns adjusting flowering phenotypes to match predicted future climates. It is therefore crucial to understand this vernalisation process. The identification of the genes involved in the vernalisation response will be important for breeding crops able to cope with the effects of climate change. In this research project, bioinformatics methods were used to investigate the effects of decreasing temperatures and photoperiods on the transcriptomes of three different wheat varieties. The Affymetrix probe-sets associated with the known vernalisation genes and their expression profiles were characterised. Further analyses showed that gene expression varied significantly between wheat varieties. Genes involved in cold stress, cold acclimatisation, sugar / lipid metabolism and disease resistance have been identified. Probe-set Ta.17293.2.S1_at was a potential biomarker for vernalisation. In Arabidopsis, hundreds of vernalisation-related genes have been investigated. These were compaired to the probe-sets present on the Affymetrix wheat GeneChip® and a total of 184 putative wheat vernalisation-related genes were identified. As a step towards understanding the vernalisation process, a putative wheat network was constructed, of which several interactions were substantiated using co-expression correlation analysis. These results indicated that histone modification may be taking place, suggestive of an epigenetic switch. In addition, Artificial Neural Network inference was used to identify several novel candidate vernalisation genes. Of specific note was SPK1, a GTP binding protein. This was putatively associated with the expression of CDF2, a DOF-type transcription factor. In order to test the functions of CDF2 and SPK1, shRNAi constructs were developed to silence these genes in vivo. Transgenic wheat plants were analysed with T0 plants.

APA, Harvard, Vancouver, ISO, and other styles

31

Rattin, Gabriela Eyng. "Effect of genotype and environment on hard wheat water absorption tolerance." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/8538.

Full text

Abstract:

Master of Science
Department of Grain Science and Industry
Jon M. Faubion
Rebecca Miller
Water absorption tolerance is an important parameter in commercial bread production. Hard winter wheat (HWW) flours have shown different water absorption tolerance behaviors in routine wheat quality analysis. Flours with high water absorption tolerance allow broader variation in water addition without affecting optimum dough conditions. Although studies have demonstrated that genotype and environmental factors affect optimum water absorption, mixing time and dough strength, there is no research defining or quantifying water absorption tolerance behavior or explaining reasons and factors affecting such behavior and its correlation with end product quality. Using the mixograph®, this study identified high and low absorption tolerance behaviors in five HRW varieties (Jagger, Jagalene, Fuller, 2137 and Overley) grown in six locations (Finney, Labette, Republic, Thomas, Riley and Sumner Counties) in Kansas, during crop year 2009. Milling, wheat and flour quality tests, Solvent Retention Capacity (SRC), damaged starch, protein composition and identification, flour and starch particle size distribution and bread baking tests were conducted and analyzed. Jagger grown at Finney County possessed the largest water absorption tolerance range while the smallest range was observed for Fuller grown at Riley and Sumner Counties. A positive high correlation was observed between water absorption tolerance and the following parameters: protein content, kernel hardness, extractable polymeric proteins, unextractable polymeric proteins, gliadins and flour particle size (41-300 μm). SDS PAGE and proteomic analyses determined that γ-gliadins were present in a significantly higher concentration in the high tolerance sample suggesting that these proteins play a primary role in water absorption tolerance behavior. The five wheat varieties grown at locations with high and low water absorption tolerance were blended together by location and test baked at three different absorption levels. Loaf volume varied between flours but did not vary between different water levels. It is unclear if this was an effect of the differing protein contents of the blends, water tolerance or both. However, a negative effect on crumb grain characteristics was observed when lower water levels were used.

APA, Harvard, Vancouver, ISO, and other styles

32

Agostinelli, Andres Mateo. "PHENOTYPIC AND GENOTYPIC SELECTION FOR HEAD SCAB RESISTANCE IN WHEAT." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/582.

Full text

Abstract:

Fusarium Head Blight (FHB) is a destructive disease caused by Fusarium graminearum that affects wheat (Triticum aestivum L.) worldwide. Breeding for resistance to FHB is arguably the best way to combat this disease. However, FHB resistance is highly complex and phenotypic screening is difficult. Molecular markers are a promising tool but breeding programs face the challenge of allocating resources in such a way that the optimum balance between phenotypic and genotypic selection is reached. An F2:3 population derived from a resistant x susceptible cross was subjected to phenotypic and genotypic selection. For phenotyping, a novel air separation method was used to measure percentage of damaged kernels (FDK). Heritability estimates were remarkably high, which was attributed to the type of cross and the quality of phenotyping. Genotypic selection was done by selecting resistance alleles at quantitative trait loci (QTL) on the 3BS (Fhb1) and the 2DL chromosomes. Fhb1 conferred a moderate but stable FHB resistance while the 2DL QTL conferred a surprisingly high level of resistance but with significant interaction with the environment. Phenotypic selection conferred higher or lower genetic gains than genotypic selection, depending on the selection intensity. Based on these results, different selection strategies are discussed.

APA, Harvard, Vancouver, ISO, and other styles

33

Thistlethwaite, Rebecca Janette. "Identification of genetic variation in heat stress, genotype screening for and mechanisms of tolerance in wheat." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17339.

Full text

Abstract:

Increasing global climatic variability will most likely increase temperatures and reduce annual rainfall in many cropping regions in the coming years. Changes in seasonal conditions are likely to have a significant impact on all food crops including wheat. This thesis aims to (1) identify genetic diversity for high temperature tolerance in bread wheat by evaluating a large number of genotypes across years and sowing dates, (2) evaluate a subset of germplasm was using different screening methods for heat tolerance (in-field controlled environment chambers and glasshouses) and (3) compare different screening methods, Field experiments were conducted between 2012 and 2015 to identify superior genotypes with tolerance to high temperature from Australian and international wheat germplasm. Yield and yield components and phenological and physiological traits were assessed each season. Mean maximum temperature between heading and maturity demonstrated that for every 1 °C rise in mean maximum temperature, grain yield decreased by approximately 230kg/ha. A subset of twenty genotypes was maintained across all years and times of sowing to assess trait stability under heat stress. A significant genotype x environment interaction was observed for yield and yield components and the size of the interaction differed by trait. In-field controlled environment chambers were designed to implement a heat shock at anthesis on normally sown materials to assess the validity of late sowing as a method for heat tolerance screening. The heat shock applied at anthesis using chambers consistently reduced grain number more than TKW, largely due to negative impacts on pollen viability. A glasshouse experiment was conducted to impose a heat shock to the same subset of twenty genotypes. Plants were heated for three days at pollen formation (meiosis) and anthesis. Heat shock at meiosis had a greater impact on yield components than heat shock at anthesis. An ideotype for the warmer conditions in northwestern NSW was developed from the trait responses and relationships with productivity traits such as yield, kernel weight and screenings. Such an ideotype would be short-statured, maintain and prolong greenness at booting and anthesis, maintain and produce larger grain, extend the vegetative period and produce a 1:1 ratio of grain to biomass.

APA, Harvard, Vancouver, ISO, and other styles

34

Lisiecki, Karol. "Reakcja genotypów pszenicy (Triticum aestivum L.) na patogeny z rodzaju Rhizoctonia." Rozprawa doktorska, Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy, 2021. http://dlibra.utp.edu.pl/Content/3620.

Full text

Abstract:

Celem pracy było uzyskanie profilów biologicznych genotypów pszenicy w kontekście reakcji oraz ewentualnej obrony przeciwko patogenom z rodzaju Rhizoctonia. Wykonana analiza składowych głównych (PCA) wykazała zróżnicowanie uruchamianych mechanizmów obronnych w zależności od genotypu patogena. W efekcie badań polowych i laboratoryjnych wyodrębniono grupy genotypów roślin o różnych poziomach podatności na działanie grzybów z rodzaju Rhizoctonia

APA, Harvard, Vancouver, ISO, and other styles

35

Gonzales, Diaz Andie Alexander Sr. "The wheat seed phytomicrobiome as a potential source of resistance to the fungal disease, Fusarium head blight." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98399.

Full text

Abstract:

Plant-associated microbes (collectively the microbiome) are important contributors to plant health. They are known to play roles in increasing yield via improving stress tolerance, promoting growth, and suppressing the activity of plant pathogens. We investigated the wheat seed-head microbiome (phytomicrobiome) as a potential source of resistance to Fusarium head blight (FHB), or scab. FHB is a devastating disease in wheat, and other cereal grains, that causes losses in both quantity, through reduced yield, and quality of grain, through the production of toxins such as Deoxynivalenol. Efforts to combat FHB have focused primarily on breeding cultivars with resistance and applying fungicides. However, new resources for combatting FHB may lie in microbiome-plant interactions. To explore host-microbiome-pathogen interactions, we used field trials to characterize the seed head bacterial community (16S rRNA gene amplicons) across planting locations, host resistance genotypes, varieties, and plant development stages. We identified bacterial amplicon sequence variants (ASVs) present in each sample and then examined ASV community composition based on our variables. Characterizing bacterial relative abundance across samples, we identified 9,063 ASVs. These ASVs clustered according to plant developmental stages or maturity plant, location, and host genotype, but not by variety or maturity group. First, comparing plants at the pre-flowering versus mature grain-head stage, we found that both bacterial community richness and evenness changed significantly. In addition to these developmental changes, we found that bacterial community structure changes across locations, even between locations. Finally, we found that, in the presence of the pathogen, ASVs cluster by host resistance genotype, and that there are important taxonomic groups that are differentially abundant in the presence of the pathogen. Overall, we found that the wheat grain-head microbiome is shaped by environment-host-pathogen interactions, and that these interactions lead to differential abundance of particular community members that may be important in the management of FHB.
Master of Science in Life Sciences
Plant associated microbes are important contributors to plant health. They are known to play roles in increasing yield via improved stress tolerance, promoting growth, and suppressing plant disease. We investigated the wheat grain-head microbial communities as a source of disease resistance. The disease is called Fusarium Head Blight (FHB) and is caused by Fusarium graminaerum. FHB is a devastating disease in wheat and other cereals, causing losses, through reduced yield and quality through the production of toxins that prohibit use of the grain. To combat FHB, research has focused on developing plants that have resistance and the application of chemical fungicides. However, new resources for combating FHB may lie in the interactions between plants and microbes. This research is focused on identifying microbes that naturally interact with the plant, and how the pathogen, Fusarium, interacts with these beneficial microbes. In field trials, we characterized the microbial community by DNA sequencing technologies across locations, wheat with varying levels of genetic resistance, and wheat developmental stages. First, between the wheat kernel samples of pre-flowering and maturity, we found significant differences in microbial community. Consistent with other studies we found that the largest changes in microbial community composition across different growing locations. Finally, we found an interaction between the grain head microbiome and host resistance state when plants were exposed to the pathogen. Overall, we find that the wheat grain head microbiome is shaped by growing location and through interactions with the plant host and pathogen.

APA, Harvard, Vancouver, ISO, and other styles

36

Day, A. D., and M. J. Ottman. "Growth Cycle, Fertilizer, Planting Rate, and Genotype Influence Barley Hay or Forage Growth in the Southwest." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200506.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Mavrodi, Olga. "Phenotypic, genotypic and colonization properties of 2,4-diacetylphloroglucinol-producing Pseudomonas spp. isolated from roots of wheat." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Dissertations/Fall2004/O%5FMavrodi%5F121004.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Tomasz, Teresa. "Vliv teploty a sucha na obsah proteinů gliadinové a gluteninové frakce u čtyř odrůd pšenice." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295720.

Full text

Abstract:

This diploma thesis deals with an influence of high temperature and water shortage on the protein content of gliadin and glutenin fractions in four varieties of winter wheat: Bohemia, Tobak, Pannonia and var. Syria with designation S46 (IG142780). The crop was grown at 26, 29, 32, 35, 38 and 41 °C during anthesis under control irrigation treatment (with soil moisture higher than 70 %) or under drought stress (with soil moisture lower than 30 %). To separate gliadins, the A-PAGE method was used, and glutenins were separated by SDS-PAGE method. Proteins were quantified by computer densitometry. Significant influence of genotype on the gluten proteins was found. Variety Pannonia has high content of -, 5-gliadins, LMW and HMW glutenins, but low content of other gliadin fractions. It was the opposite in the other varieties. Due to temperature, as well as drought, there was an increase in the content of all gluten fractions, especially of HMW glutenins, 1,2-gliadins and total gliadins. The largest increase in the gluten fractions due to drought was observed in Syria variety. In other varieties simultaneous exposure to drought and heat caused decrease in gliadin content, but increase in glutenin content. Drought at high temperatures reduced gliadin-to-glutenin ratio, mostly in Bohemia variety. This ratio has increased due to the temperature, especially in Tobak variety. For Syria variety, no effect of stress conditions was found on gliadin-to-glutenin ratio.

APA, Harvard, Vancouver, ISO, and other styles

39

Haji, Hussein Mao. "Causes of genotype by environment interaction in winter and spring wheat grown in Ontario." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27454.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Cosser, Nicola. "Genotype and systems interactions on grain yield and quality for organic wheat (Triticum aestivum) production." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320192.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Chairi, Fadia. "Increasing genotypic productivity in post Green Revolution durum wheat: the case of Spain." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/671914.

Full text

Abstract:

It is of strategic importance for Mediterranean agriculture to develop new varieties of durum wheat with greater production potential, together with a better adaptation to adverse environmental conditions and better quality of grain. While durum wheat, which is the most strategic crop in the south Mediterranean agriculture, has benefited as other cereals of the Green Revolution, genetic progress in recent decades has been less evident, partly masked by climate change, and the underlying physiological mechanisms are not evident. For this propose, the objective is to evaluate whether there have been agronomic and physiological changes associated with the genetic improvement of durum wheat grown in Spain after the Green Revolution and the environmental conditions where breeding gains have been higher. The study was based on a collection of 20 commercial varieties, grown in Spain between the beginning of the 70s of the last centuries and the present. The set was readapted during the last two cropping cycles and increased to a total of 23 cultivars, including more recent cultivars, released during the present decade. Cultivars were compared through consecutive years in wide range growing conditions secured by growing in three different sites differing in latitude and temperature, together with the implementation of support irrigation and different planting times. Changes in the genetic gain of the yield were evaluated between 2014 and 2016. Change in the agronomic and physiological parameters related to the genetic progress was evaluated between 2015- 2016, and the changes caused by the improvement in the adaptation patterns through the study of the genotype by environment (GE) interaction was evaluated between 2017 and 2018. It has been observed that the rate of genetic progress in the yield of durum wheat in Spain after the Green Revolution has been low it was estimated on 24 kg ha-1 y-1 (0.44% y-1 in term of relative gain) between 1980 and 2003 and has even stopped during the last decade until 2010. It was mainly due to increases in the number of kernels per spike (117 kernels m-2 y-1), and spikes per unit area (0.24 kernels spike-1 y-1), while no clear trend in some grain quality traits (TKW and grain N concentration). Moreover, areal biomass at harvest and grain nitrogen yield increased with the year of release of the cultivars for the entire period. In addition, it has been observed that the more productive genotypes were characterized by a plant height of around 85 cm, small erect flag leaves, more open stomata, a better balance between N sources and N sinks and a higher capacity to re-fix CO2 respired by the grain. Moreover, in general the non-laminar parts of the plants play a key role in providing assimilates during grain filling. Also, that the high heritability of most of the studied parameters allows their consideration as traits for phenotyping durum wheat better adapted to a wide range of Mediterranean conditions. On the other hand, an improvement in genetic yield has been reported in warm environments and under optimal water conditions, environments similar to those of from where the germplasm provenance release or origin. The adaptation of semi-dwarf durum in Spain has shown a tendency to specific adaptation rather than large-scale adaptation. Two different patterns of selection have been reported due the G×E interaction and change in the ranking of genotypes: in the high yielding environments, plant favors more water uptake, with more transpiration and more open stomata (more negative value of δ13C, whereas, in low yielding environments, plant close stomata and favors more water use efficiency (positive value of δ13C).
El trigo duro, que es el cultivo más estratégico en la agricultura del sur del Mediterráneo, se ha beneficiado como otros cereales de la Revolución Verde, el progreso genético en las últimas décadas ha sido menos evidente, en parte enmascarado por el cambio climático, y los mecanismos fisiológicos subyacentes no son evidentes. Se ha observado que la tasa de progreso genético en el rendimiento del trigo duro en España después de la Revolución Verde ha sido baja, se estimó en 24 kg ha-1 año-1 entre 1980 y 2003 e incluso se detuvo durante la última década hasta 2010. Se debió principalmente al aumento en el número de granos por espiga, y espigas por unidad de área, aunque no hay una tendencia clara en algunos rasgos de calidad de grano (TKW y concentración de N de grano). Además, la biomasa área en la cosecha y el rendimiento de nitrógeno en grano aumentó con el año de liberación de los cultivares durante todo el período. Además, se ha observado que los genotipos más productivos se caracterizaron por una altura de planta de alrededor de 85 cm, pequeñas hojas de bandera erectas, estomas más abiertos, un mejor equilibrio entre las fuentes de N y los sumideros de N y una mayor capacidad para re-fijar CO2 Respirado por el grano. Además, en general, las partes no laminares de las plantas juegan un papel clave en el suministro de asimilados durante el llenado del grano. Por otro lado, se ha informado una mejora en el rendimiento genético en ambientes cálidos y en condiciones óptimas de agua, ambientes similares a los de donde se origina el germoplasma. La adaptación del durum semi-enano en España ha mostrado una tendencia a la adaptación específica en lugar de la adaptación a gran escala. Se han informado dos patrones diferentes de selección debido a la interacción G × E: en los entornos de alto rendimiento, la planta favorece una mayor absorción de agua, con más transpiración y más estomas abiertos, mientras que, en entornos de bajo rendimiento, planta estomas cercanos y favorece una mayor eficiencia en el uso del agua

APA, Harvard, Vancouver, ISO, and other styles

42

Engle, Jessica S. "Pathogenic characterization, distribution in Ohio and wheat genotype reactions to Stagonospora nodorum and Pyrenophora tritici-repentis." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117382547.

Full text

Abstract:

Thesis (Ph.D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xxi, 195 p.; also includes graphics. Includes bibliographical references (p. 184-195). Available online via OhioLINK's ETD Center

APA, Harvard, Vancouver, ISO, and other styles

43

Schidlowski, Lucas Leonardo. "Produtividade e qualidade industrial de trigo em diferentes anos e regiões de cultivo." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/873.

Full text

Abstract:

A produtividade e a qualidade tecnológica do trigo são influenciadas por fatores genéticos, ambientais e de manejo. A participação do ambiente na definição de caracteres componentes do rendimento e atributos qualitativos de farinha requer extensiva avaliação de genótipos em vários locais durante anos. O objetivo deste trabalho foi avaliar o efeito de anos (2007 a 2011) e regiões de cultivo (Abelardo Luz- SC, Cascavel-PR, Castro-PR, Guarapuava-PR, Não Me Toque- RS e Palotina-PR) sobre a qualidade industrial e produtividade de grãos em conjuntos de ensaios de trigo (Triticum aestivum L.), com vistas a recomendação de cultivares e identificação de regiões que maximizem a qualidade de panificação. Foram realizadas as análises de variância conjunta e calculadas as estatísticas de comparação de médias, associação entre caracteres e adaptabilidade e estabilidade dos genótipos às diferentes regiões de cultivo, utilizando analises gráficas GGE Biplot e análises AMMI. Os resultados indicam que todos os caracteres avaliados foram influenciados pelo genótipo (G), ambiente (E) interação GxE. Os caracteres determinantes da qualidade de panificação de trigo têm sua variação fenotípica controlada principalmente pelo efeito genético. As cultivares CD 150, CD 108 e IPR 85 apresentaram excelente comportamento quanto à qualidade de panificação. O ambiente de teste Não-Me-Toque é ideal para seleção de genótipos com foco no rendimento de grãos e massa do hectolitro. Ambientes ideais para a seleção de genótipos com foco na qualidade de panificação incluem, em ordem, Abelardo Luz, Cascavel e Guarapuava.
The productivity and technological quality of wheat is influenced by genetic, environmental and management factors. The environmental contribution in the definition of component traits of yield and quality attributes of flour requires extensive evaluation of genotypes in multiple locations for years. The objective of this study was to evaluate the effect of years (2007-2011) and growing regions (Abelardo Luz- SC , Cascavel - PR, Castro - PR, Guarapuava - PR , Não-Me-Toque - RS and Palotina - PR) on the quality industrial and grain yield in sets of trials of wheat ( Triticum aestivum L.), with a view to recommending cultivars and identification of regions that maximize the quality of baking. Analyses of joint variance and calculated statistical comparison of means , association between character and adaptability and stability of genotypes to different growing regions, using graphical GGE Biplot analysis and AMMI analysis were performed. The results indicate that all traits were influenced by genotype (G), environment (E) interaction GxE. The determinants of quality characters of wheat bread have their phenotypic variation mainly controlled by genetic effects. The CD 150, CD 108 and IPR 85 cultivars showed excellent behavior in relation to baking quality. The test environment Não-Me-Toque is ideal for selection of genotypes with a focus on yield and hectoliter mass. Ideal environments for the selection of genotypes with a focus on quality of bread making, in order, Abelardo Luz, Cascavel and Guarapuava.

APA, Harvard, Vancouver, ISO, and other styles

44

Filippini, Nicola. "Brain structure, function and connectivity associated with APOE genotype : what changes when?" Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525306.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Di, Loreto Alessandro <1985&gt. "Nutraceutical Value of Durum Wheat: Influence of Environment and Genotype in a Large Scale Experimental Trial." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7531/.

Full text

Abstract:

Grain quality is well known as one of the most interesting breeding objectives in Mediterranean countries. It still has great importance in wheat markets because of the increased interest of the consumers for high-quality staple food such as pasta, couscous and various types of bread. The performance of many quality characteristics depends greatly on environmental conditions and, in this context, organic agriculture could guarantee a durum wheat material with high nutraceutical value for healthy food production and special dietary uses. Among organic wheat production, KAMUT® khorasan wheat (Triticum turgidum ssp. turanicum (Jakubz.)) has attracted great attention due to its specific nutritional and functional properties (antioxidant, anti-inflammatory, and prebiotic activities). The aim of this thesis was to evaluate the environmental and climatic effects on the nutritional and nutraceutical quality of organic durum and durum-type wheat varieties. The work was subdivided into three main sections aimed at understanding the dynamic affecting the accumulation of nutritional and functional compounds in wheat caryopsis of durum and durum type wheat varieties. The first two section provide a complete characterization of KAMUT® khorasan grain. This is a distinctive study: first a collection of the same organically grown genotype collected during two decades of cultivation was characterized for nutritional and functional properties; then the investigation has shifted to the same crop harvested in a vast region (180000 km2), including several different environments. In the third section 24 old and modern durum and durum-type wheat varieties, cropped in the same location and growing season, were analyzed in order to determine and compare the phenolic composition. Results obtained gives a fundamental understanding of durum wheat grains composition in terms of nutrient and bioactive compounds.

APA, Harvard, Vancouver, ISO, and other styles

46

Paiva, Ana Giselda Simões. "Genotypic and environmental effects on the concentration of healthy compounds of four durum wheat varieties." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15497.

Full text

Abstract:

Mestrado em Biotecnologia - Biotecnologia Alimentar
Wheat is one of the most important grain in human diet and it is the most grown cereal crop wordwide. Nowadays since global climatic changes have become more important to food production, we asked whether climatic conditions and genotype would influence the production of healthy compounds on old and new varieties of durum wheat. Resistant starch and phenolic acids were quantified by HPLC techniques to evaluate the environmental and genotypic effects and to characterize four durum wheat species grown in South Italy. Environment had a strong impact on the production of resistant starch and phenolic acids, while genotype had the greastest effect on the same compounds. The production of phenolic acids tended to increase by the effect of winter sowing season and the year 2014 during the grain filling period. Ferulic and sinapic acid were the most abundant in the four varieties. The two new Ethiopian lines were more efficient on the production of phenolic acids and resistant starch, while the old genotype Trinakria and its genetic modified pair showed to be slightly less productive. Wheat based products higher in phenolic acids and resistant starch might lead to a diet richer in bioactive substances that promote health.
O trigo é um dos cereais mais importantes na alimentação humana e um dos mais produzidos a nível mundial. No momento em que as alterações climáticas parecem ser cada vez mais importantes na produção de alimentos, foi questionado se as condições climáticas e o genótipo poderiam influenciar a produção de compostos benéficos para a saúde em variedades antigas e novas de trigo duro. O amido resistente e os ácidos fenólicos foram quantificados através de técnicas cromatográficas para avaliar os efeitos ambientais e genotípicos e para caracterizar quatro variedades de trigo duro cultivadas no sul de Itália. O ambiente influenciou a produção de amido resistente e de ácidos fenólicos, enquanto que o genótipo teve o maior impacto nestes. A produção de ácidos fenólicos tendeu a aumentar pelo efeito da estação invernal e do ano 2014 no período de enchimento dos grãos. Os ácidos ferúlico e sinápico foram os mais abundantes nestas variedades. As duas linhas genotípicas Etiopia novas foram as mais eficientes na produção de ácidos fenólicos e amido resistente, enquanto que o genótipo antigo Trinakria e o seu par geneticamente modificado mostraram ser ligeiramente menos produtivos. Pensa-se que os produtos alimentares à base de trigo com um conteúdo de amido resistente e ácidos fenólicos elevado conduzem a uma dieta mais rica em substâncias bioactivas que promovem a saúde humana.

APA, Harvard, Vancouver, ISO, and other styles

47

Russell, Kathleen. "GENOTYPE × ENVIRONMENT × MANAGEMENT: IMPLICATIONS FOR SELECTION TO HEAT STRESS TOLERANCE AND NITROGEN USE EFFICIENCY IN SOFT RED WINTER WHEAT." UKnowledge, 2017. http://uknowledge.uky.edu/pss_etds/91.

Full text

Abstract:

The complex interaction of genetics, environment and management in determination of crop yields can interfere with selection progress in breeding programs. Specifically, the impact on selection for nitrogen use efficiency (NUE) in wheat (Triticum aestivum L.) under changing climatic conditions can be confounded by these interactions. Temperature increases for the southeastern United States are projected to range from 1-3°C by 2050 with nighttime temperatures increasing more rapidly than day temperatures. High temperatures are known to affect crop development and breeding for tolerance to heat stress is difficult to achieve in field environments. We utilized a multi-environment trial to assess variation in traits associated with NUE based on interactions of genotype x environment x management (G×E×M). All genotypes in the study responded favorably to lower than recommended nitrogen rates. Incremental application of N rates increased yield and post-anthesis N uptake significantly. Additionally, two multi-year studies investigating the effects of heat stress on soft red winter wheat varieties were conducted during the 2015-2016 growing seasons at the University of Kentucky Spindletop Research Farm in Lexington, KY. Thirty-six to 40 genotypes were chosen based on the combination of traits for vernalization and photoperiod sensitivity determined using marker analysis. Warmed environments were created through active and passive warming. Heading date, averaged across genotypes, shifted 1-5 days earlier in the actively warmed environment compared to the ambient environment across both years (p ≤0.05). Grain yield, averaged across genotypes, was significantly reduced in the actively warmed environment by 211.41 kg ha-1 (p ≤0.05) or 4.84%; however yield response to environment varied among genotypes with several genotypes displaying an increased yield in the warmed environment. Night temperature increases ranged from 0.27-0.75 °C above ambient temperature in the passively warmed environment. Grain yield, averaged across genotypes, was significantly reduced in the passively warmed environment by 224.29 kg ha-1 (p ≤0.05) or 6.44%; however, yield response to environment varied among genotypes with several genotypes displaying an increased yield in the warmed environment. Yield reductions are attributed to nitrogen utilization being reduced by 9.4% (p ≤0.001) under increased night temperatures.

APA, Harvard, Vancouver, ISO, and other styles

48

Bec, Sladana. "ROLE OF THE SEXUAL CYCLE IN DEVELOPMENT OF GENOTYPIC AND PHENOTYPIC DIVERSITY IN Gibberella zeae." UKnowledge, 2011. http://uknowledge.uky.edu/plantpath_etds/2.

Full text

Abstract:

Gibberella zeae (anamorph Fusarium graminearum) is a homothallic ascomycete pathogen that is responsible for causing Fusarium head blight (FHB) of wheat and small grains. In addition to causing a reduction in yield, harvested grain is frequently contaminated with trichothecene mycotoxins that are harmful for human and animal health. Use of wheat varieties with resistance to FHB is an important strategy to lower its impact. In order to produce varieties with durable resistance, we must understand the origin and degree of genetic diversity present in the pathogen population. In my research, I focused my efforts on an investigation of the role of mating and sexual development in the generation of genotypic and phenotypic variability in G. zeae. The goal of one part of my work was to develop new genetic markers that can be used to monitor out-crossing and genetic diversity in the population. I also optimized gene deletion protocols for G. zeae so that I could produce mutant and control strains to address my research hypothesis that MAT genes play a direct role in pathogenicity. Application of novel repetitive RFLP probes to a group of G. zeae isolates originating from and near Kentucky revealed a surprisingly high degree of diversity in these local populations. Diversity between locations was greater than that within locations, suggesting the relative importance of local inoculum sources. The probes were also useful as genetic markers for segregation analysis. I crossed two genetically closely related, and commonly used, laboratory strains of G. zeae and found that this resulted in transgressive segregation for both aggressiveness and toxigenicity. I showed that the very high and very low levels of aggressiveness and toxigenicity in transgressive segregants are heritable. I also showed that selfing produced a higher degree of diversity in these traits among the progeny than was observed among conidial progeny. This suggests the presence of epigenetic factors that impact pathogenicity. Sexual behavior in G. zeae is under the control of MATing type genes. I deleted the complete MAT1 locus, and the MAT1-1-1, and MAT1-2-1 genes separately. Deletion of each of the targeted sequences produced the expected shifts in fertility phenotype. The mat1KO strains became asexual, while mat1-1-1KO and mat1-2-1KO strains shifted to obligate heterothallism. Deletion of the MAT1-1-1 and MAT1-2-1 genes had a negative effect on aggressiveness and mycotoxin production in planta, but deletion of the complete MAT1 locus had no effect. The set of mutant and ectopic control strains that I generated will be a useful asset that will be made available to the research community.

APA, Harvard, Vancouver, ISO, and other styles

49

Weber, Tessmann Elisane. "IMPACT OF A WARMED ENVIRONMENT, SPIKE MORPHOLOGY AND GENOTYPE ON FHB LEVELS IN A SOFT RED WINTER WHEAT MAPPING POPULATION." UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/116.

Full text

Abstract:

Fusarium head blight (FHB) is a serious disease of wheat (Triticum aestivum) and other small grains; disease severity is affected by temperature and rainfall. This research comprised three studies: an artificially warmed experiment during 2016-2017, a morphology study and an FHB resistance screening study in 2015-2016, using approximately 250 wheat cultivars and breeding lines from programs in the eastern US. The location was the University of Kentucky Spindletop Research Farm in Lexington, KY. Higher levels of Fusarium damaged kernels and the toxin deoxynivalenol (DON) were observed in the warmed treatment compared to the control, and plant development was accelerated. In the FHB resistance screen, significant (p < 0.05) genotype differences for all traits were observed. A GWAS identified 16 SNPs associated with resistance and susceptibility, ranging from -2.14 to 4.01%. Three DON-associated SNPs reduced toxin levels by 3.2, 2.1, and 1.5 ppm. In the morphology study, negative correlations were observed among morphological and disease traits. Small effect SNPs were identified for all morphological traits, which might be useful in genomic selection; traits like spike length, spikelet number and inclination could be used in phenotyping. Response to warming indicates that existing resistance sources may be less effective in a warming climate.

APA, Harvard, Vancouver, ISO, and other styles

50

Vázquez, Daniel. "Effects of genotype and environment on polyphenol oxidase activity and related properties of red and white wheats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ56149.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Wheat genotypes'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles