Genome-wide association study of grain micronutrient concentrations in bread wheat

Bread wheat(Triticum aestivum)is a staple food crop worldwide.The genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing population.Here,45,298 single-nucleotide polymorphisms(SNPs)from 55K chip arrays were used to genotype a panel of 768 wheat cultivars,and a total of 154 quantitative trait loci(QTLs)were detected for eight traits under three environments by genome-wide association study(GWAS).Three QTLs(qMn-3B.1,qFe-3B.4,and qSe-3B.1/qFe-3B.6)detected repeatedly under different environments or traits were subjected to subsequent analyses based on linkage disequilibrium decay and the P-values of significant SNPs.Significant SNPs in the three QTL regions formed six haplotypes for qMn-3B.1,three haplotypes for qFe-3B.4,and three haplotypes for qSe-3B.1/qFe-3B.6.Phenotypic analysis revealed significant differences among haplotypes.These results indicated that the concentrations of several nutrient elements have been modified during the domestication of landraces to modern wheat.Based on the QTL regions,we identified 15 high-confidence genes,eight of which were stably expressed in different tissues and/or developmental stages.TraesCS3B02G046100 in qMn-3B.1 and TraesCS3B02G199500 in qSe-3B.1/qFe-3B.6 were both inferred to interact with metal ions according to the Gene Ontology(GO)analysis.TraesCS3B02G199000,which belongs to qSe-3B.1/qFe-3B.6,was determined to be a member of the WRKY gene family.Overall,this study provides several reliable QTLs that may significantly affect the concentrations of nutrient elements in wheat grain,and this information will facilitate the breeding of wheat cultivars with improved grain properties.

Impact of Seawater Irrigation on seed germination and seedling growth of Ten Bread Wheat(Triticum aestivum L.)Genotypes

Objective:Seawater leakage in Al-Jabal Al-Akhdar East Libya's coastal areas is one of the most biggest obstacles to farmers obtaining a highly productive crop.As a result,the experiment was conducted in a laboratory to find out the impact of irrigation with seawater on the salt tolerance of Acsad Bread wheat genotypes.Method:Ten genotypes(1398,1492,1514,1522,1524,1536,1538,1544,1550,and 1562),obtained from the Arab Center for the Studies of Arid Zones and Dry Lands Acsad,were used in the study,10 seeds of each genotype with three repetitions were germinated under four seawater concentrations(10,20,30 and 40%).Results:The results showed that there were highly significant(P≤0.05)differences in the genotypes’response to all salinity concentrations,Which led to decreasing germination percentage,delaying the average germination time,and decreasing radical/plumule length and seedling fresh/dry weight compared with a control.As noted genotypes(1524,1522 and 1514)were able to germinate in all concentrations of seawater,and gave the best average for all the studied traits.Also,the study indicated that a concentration of seawater of 40%was the most toxic for all wheat genotypes.The results of this study categorize the wheat genotypes into tolerant genotypes(1524,1522 and 1514),moderate tolerant(1492,1536),and sensitive(1398,1538,1544,1550 and 1562).Conclusion:The results concluded that the possibility of wheat crops agriculture into tolerant in Libyan coastal locations in which seawater concentration did not exceed 30%.

Evaluation on Chinese Bread Wheat Landraces for Low pH and Aluminum Tolerance Using Hydroponic Screening

Aluminum （Al） toxicity often takes place in acidic soils with a pH of 5.5 or lower. Breeding and cultivation of Al tolerance wheat can partially protect wheat escaping from Al toxicity. The scarcity of the tolerant sources impedes the wheat breeding. In order to find new Al tolerance sources, we screened 173 bread wheat landraces from Tibet of China using hydroponic screening. It was indicated that： （1） There were diversities on the root regenerate length （RRL）. The RRL of a large of landraces were longer than 7.00 cm in pH 7 （58.38%） and pH 4.5 （66.47%）, but shorter than 5.00 cm in pH 4.5 ＋50μM Al^3＋ （80.93%）. The low pH showed either promotion or restraining effects depend on landraces, but Al toxicity under low pH only showed restraining effects on the root elongation. （2） There were also diversities on root tolerance index of low pH （RTI 1） or root aluminum tolerance index （RTI2） among cultivars. The RTI1 varied from a narrow range but with relatively high value （0.8722-1.2953） in comparison with that of RTI2 （0.3829-1.0058）, and the RTI1 of approximately 60% landraces was higher than 1.0000, the RTI2 of only 19.07% landraces was higher than 0.7000, suggesting that Al toxicity acted as an important factor for the reduction of the root elongation under acidic soils. （3） The RTI 1 of many wheats was higher than 1.0000, and As2256 and As2295 were the most tolerant for low pH, with RTI1 1.2953 and 1.2925, respectively. （4） Based on RTI2, seven wheats showed similar or higher tolerance to Al toxicity than Chinese Spring （CS）, a known tolerance wheat. Much better tolerance existed in landraces of As1543 and As1242, which can be used as the new parents for Al tolerant breeding.

Tissue Nitrogen and Fructan Translocation in Bread Wheat

Translocation of previously accumulated nitrogen and carbohydrates from vegetative tissue of the wheat plant is a major assimilate source for grain filling. This study was conducted to examine genotype differences in nitrogen and fructan translocation and their relationships to grain yield and protein content. Effects indicated that significant genotype differences existed for nitrogen accumulation at anthesis and fructan at milk stage and their translocation. Two high protein genotypes, Cunningham and PST90-19, accumulated more nitrogen before anthesis and had greater nitrogen translocation, but lower post-anthesis nitrogen uptake, than two low protein genotypes, SUN109A and TM56. Among plant parts, leaves were the major storage for tissue nitrogen and provided the overwhelming proportion of the total nitrogen translocation, whereas for fructan accumulation and translocation it was the stems. The two high protein genotypes had a higher percentage of their grain nitrogen derived from nitrogen translocation, while for the two low protein ones, it was from post-anthesis nitrogen uptake and assimilation. Increasing nitrogen application increased nitrogen accumulation and translocation, but decreased fructan accumulation and translocation. High grain protein content was associated with high nitrogen translocation from leaves, stems and the total plant, while high grain yield was related to high fructan translocation from stems and the total plant. Fructan translocation was negatively correlated to grain protein content. Nitrogen and fructan translocation were not correlated with each other.

Investigation on Paste Property of Chinese Bread Wheat Varieties

Starch viscosity is closely associated with noodle quality. RVA(rapid viscosity analyzer) was used to investigate the paste property of leading Chinese wheat varieties arid 38 Australian wheat lines. Results showed that significant variability for RVA parameters was observed among Chinese wheat varieties, particularly among spring wheat varieties. In general, Australia wheat lines performed better paste characters than that of Chinese winter wheats. Genotype (G), environment (E) and genotype by environment (G×E) interaction affected all paste traits. Correlation analysis indicated that peak viscosity correlated highly and significantly with viscosity, breakdown, setback, final viscosity, peak time, and falling number(r = 0.56-0.93, P<0.01). However breakdown was not significantly associated with most paste properties. Paste characters increased from low to high latitude both in the north and south part of Yellow and Huai Valley.

Multivariate Cluster and Principle Component Analyses of Selected Yield Traits in Uzbek Bread Wheat Cultivars

Investigation of genetic diversity of geographically distant wheat genotypes is a useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues > 1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was the greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18,373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).

Genotype×tillage interaction and the performance of winter bread wheat genotypes in temperate and cold dryland conditions

Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.

Effects of Plant Growth Promoting Rhizobacteria (PGPR) on In Vitro Bread Wheat (Triticum aestivum L.) Growth Parameters and Biological Control Mechanisms

Three endemic plants rhizosphere (Astragalus gombo Coss. & Dur., Daucus sahariensis Murb., Ononis angustissima Lam.), were used for actinomycetes isolation. Ninety-three (93) isolates have been screened to evaluate their antagonistic properties against phytopathogenic microorganisms and to determine their biocontrol properties against Fusarium culmorum, especially responsible for several cereal diseases like font’s seedlings, rust, and burn of ears. Four (04) isolates (D2, D5, D8, and AST1) have been in vitro tested to determine PGPR effect and biocontrol characters of bread wheat (Triticum aestivum L.), Hidhab (HD) variety cultivated in the Murashigue and Skoog (MS) culture medium. The aim of this study is the evaluation of antagonistic isolates of pathogenic fungi F. culmorum, without and within commercial fungicide (Tebuconazole, 60 g/l) solution. Our results showed clearly that these isolates have a significant effect on seed germination and seedling growth. However, results argue that these actinomycetes isolates show a very interesting activity compared to the commercial fungicide. As a result, these bacteria isolates can be used as biocontrol agents against Fusarium wilt disease of wheat, which have a beneficial effect on growth parameters.

Layering Precision Land Leveling and Furrow Irrigated Raised Bed Planting: Productivity and Input Use Efficiency of Irrigated Bread Wheat in Indo-Gangetic Plains

Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices.

Yield and Yield Components of Bread Wheat as Influenced by Water Stress, Sowing Date and Cultivar in Sokoto, Sudan Savannah, Nigeria

Field experiments were conducted during 2009/10 and 2010/2011 dry seasons at the Fadama Teaching and Research Farm of the Usmanu Danfodiyo University, Sokoto, in the Sudan Savanna ecological zone of Nigeria (latitude 13°01'N;longitude 5°15'E, altitude of 350 m above sea level) to study the effect of water stress, sowing date and cultivar on yield and yield components of wheat (Triticum aestivum L.). The treatments consisted of factorial combination of water stress at three critical growth stages which was imposed by withholding water at tillering, flowering, grain filling and control (no stress), four sowing dates (21st November, 5th December, 19th December and 2nd January) and two bread wheat cultivar (Star 11 TR 77173/SLM and Kuaz/Weaver), laid out in a split-plot design with three replications. Water stress and date of sowing were assigned to the main-plot, while variety was assigned to the sub-plots. Result revealed that water stress at tillering significantly reduced spike length and grains per spike. Whereas, water stress at flowering and grain filling significantly reduced 1000-grain weight, grain yield and harvest index. Results also indicated significant (P st November and 5th December and lowest at 19th December and 2nd January, therefore wheat should be sown in November or at least first week of December in this area and other area with similar climate. Variety had significant effect on spike per m-2, grain yield and harvest index. Water stress at flowering and grain filling should be avoided as they are the most critical growth stages in yield determination in wheat, because plants cannot recover, while delay in sowing resulted in reduction in yield and yield components. Star II TR 77173/SLM is therefore recommended for the area.

QTL analysis for some quantitative traits in bread wheat

Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) sug- gested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection.

Genotype by Environment Interaction for Grain Yield and Association among Stability Parameters in Bread Wheat (<i>Triticum aestivum</i>L.)

Bread wheat (Triticum aestivum L.) is most important cereal crop in Ethiopia. Lack of genotypes with wide stability across environments has been one of the most important constraints of wheat production in the country. Field experiments were conducted in Halaba and Bule, South Ethiopia, in 2016 and 2017, in order to estimate grain yield stability and association among stability parameters. Fifteen improved bread wheat genotypes were grown under randomized complete block design with three replications. Mean yield for Halaba 2016, Halaba 2017, Bule 2016 and Bule 2017 was 3.83, 1.89, 2.90 and 3.59 tons/ha, respectively. Genotypes Lemu (3.25 tons/ha) and Mandoyu (3.18 tons/ha) had high mean yield, and low values of environmental variance (S2i), coefficient of variation (CVi), stability variance (δ2i), ecovalence (Wi) and deviation from regression (S2di). Genotypes Biqa (3.69 tons/ha) and Shorima (3.66 tons/ha) had high mean yield, coefficient of regression (bi) and coefficient of determination (R2i ≥ 0.94) as well as low values of δ2i, Wi and S2di. Grain yield had positive rank correlation with bi (r = 0.75, p 2i (r = 0.70, p δ2i, Wi and S2di was high (r ≥ 0.98, p , Mandoyu and Hidase, and Biqa and Shorima would be recommended for wide adaption, and for more favorable environments, respectively. It could also be suggested that one of Wi, δ2i, S2di and rank sum would be used for ranking of genotypes.

CSCS:a chromatin state interface for Chinese Spring bread wheat

A chromosome-level genome assembly of the bread wheat variety Chinese Spring(CS)has recently been published.Genome-wide identification of regulatory elements(REs)responsible for regulating gene activity is key to further mechanistic studies.Because epigenetic activity can reflect RE activity,defining chromatin states based on epigenomic features is an effective way to detect REs.Here,we present the web-based platform Chinese Spring chromatin state(CSCS),which provides CS chromatin signature information.CSCS indudes 15 recently published epigenomic data sets including open chromatin and major chromatin marks,which are further partitioned into 15 distinct chromatin states.CSCS curates detailed information about these chromatin states,with trained self-organization mapping(SOM)for segments in all chromatin states and JBrowse visualization for genomic regions or genes.Motif analysis for genomic regions or genes,GO analysis for genes and SOM analysis for new epige-nomic data sets are also integrated into CSCS.In summary,the CSCS database contains the combina-torial patterns of chromatin signatures in wheat and facilitates the detection of functi onal elements and further clarification of regulatory activities.We illustrate how CSCS enables biological insights using one example,demonstrating that CSCS is a highly useful resource for intensive data mining.CSCS is available at http://bioinfo.cemps.ac.cn/CSCS/.

Breeding for pre-harvest sprouting resistance in bread wheat under rainfed conditions

Pre-harvest sprouting in wheat is the germination of seeds within the spikes when rains occur after or during grain ripening, which occurs commonly in the barani tract of Pakistan. Therefore, 10 cultivars and five advanced lines of spring bread wheat were evaluated for pre-harvest sprouting resistance. After natural rainfall,seeds were immediately collected from the wet spikes and tested for germinating ability. Three different germination tests were applied to hand-threshed seed:(1) spikes threshed on the day of sampling and germination tested immediately,(2) spikes threshed on the day of sampling and germination tested 1 week later, and(3) spikes threshed 1 week after sampling and germination test immediately after threshing. Seeds and spikes kept for 1 week were place on blotting paper at room temperature.Cultivars BARS-09, 09 FJ17, Doukkala-12, NARC-09 and Ouassou-20 exhibited higher sprouting resistance while other genotypes were susceptible to pre-harvest sprouting in each of the three tests. A diallel crossing was conducted with six susceptible and two resistant genotypes to assess the genetic behavior of pre-harvest sprouting resistance.The combining ability(CA) demonstrated a higher proportion of additive genetic effects for sprouting resistance, because of higher variance of general and specific CA for both parameters under study. Doukkala-12 and BARS-09 showed increased pre-harvest sprouting resistance in their F1 descendants.

Relationship between physicochemical characteristics of Korean wheat flour and quality attributes of steamed bread

The purpose of this study is to identify major factors affecting the manufacture and quality of steamed bread,consumed in Southeast Asia including China,Japan,and Korea.Hence,flours of 11 Korean wheat cultivars were used to evaluate quality attributes of two different styles of steamed bread,Korean style steamed bread(KSSB)and northern-style Chinese steamed bread(NSCSB).KSSB prepared more ingredients and higher optimum water absorption of dough than NSCSB because Korean consumers prefer white and glossy surface and soft crumb.KSSB showed lower height,larger diameter and volume of steamed bread,higher stress relaxation,and softer texture of crumb than NSCSB.The correlation between flour characteristics and quality of steamed bread was different in KSSB and NSCSB.About 90%of variability in the height and volume of KSSB could be predicted from protein content,mixing tolerance of Mixograph,average particle size of flour,final viscosity and solvent retention capacity.Protein content and quality parameters also could explain the variation of steamed bread height in NSCSB.Korean wheat carrying Glu-A3c allele produced higher volume of steamed bread(704.7 mL)than Glu-A3d allele(645.8 mL)in KSSB,although there was no significant difference in volume of NSCSB by glutenin compositions.Glu-D1d and Glu-A3c alleles had softer texture of crumb than Glu-D1f and Glu-A3d alleles in KSSB,Glu-B3i allele also showed lower hardness of crumb than their counterpart allele in NSCSB.Hard wheat showed higher height and volume of steamed bread,and lower stress relaxation and hardness of crumb than soft wheat in KSSB.

Effect of Waxy Wheat Flour Blends on the Quality of Chinese Steamed Bread

Steamed bread is very popular in the East and Southeast Asian regions, and its quality is affected by some physicochemical properties. Chinese steamed bread was made by adding waxy flour into normal wheat flour in the present study. The results showed that specific volume was not affected by the proportions of waxy flour, whereas, adding waxy flour decreased the appearance, color, texture, elasticity, stickiness, and the total score of Chinese steamed bread. However, there were no significant differences in all values when the proportions of waxy flour were below 10%. All evaluations but specific volume of Chinese steamed bread were positively influenced by the peak viscosity, resistance, and maximum resistance. When the waxy flour proportions were below 25%, the firmness of Chinese steamed bread stored at -18℃ for 3 days gradually decreased with the increase of waxy flour. It was revealed that the qualities of Chinese steamed bread cannot be improved by waxy flour but it can be widely used in frozen storing food in the future.

Optimization of Bread Preparation from Wheat Flour and Malted Rice Flour

The feasibility of partially replacing wheat flour with malted rice flour in bread making was evaluated in several formulations, aiming to find a formulation for the production of malted rice-wheat bread with better nutritional quality and consumer acceptance. The whole grains of a local rice variety （Oryza sativa L. subsp. indica var. Mottaikaruppan） were steeped in distilled water （12 h, 30°C） and germinated for 3 days to obtain high content of soluble materials and amylase activity in bread making. The quality of bread was evaluated by considering the physical and sensorial parameters. When the wheat flour was substituted with malted rice flour, 35% substitution level and the malted rice flour from 3 days of germination was the best according to the physical and sensory qualities of bread. The quality of bread was improved by the addition of 20 g of margarine, 20 g of baking powder and 20 g of yeast in 1 kg of flour. Among different ratios of yeast and baking powder, 2：1 was the best. Bread improver containing amylases and oxidizing agents at the concentration of 40 g/kg was selected as the best concentration. When comparing the final formulation made in the bakery with wheat bread, malted rice-wheat bread contains more soluble dietary fiber （0.62%）, insoluble dietary fiber （3.95%）, total dietary fiber （4.57%） and free amino acid content （0.64 g/kg） than those in wheat bread （0.5%, 2.73%, 3.23% and 0.36 g/kg, respectively）.

Effect of Waxy Wheat Flour Blends on the Quality of Fresh and Stale Bread

Starch is the major component in the wheat kernel, which is mainly composed of amylose and amylopectin. The wheat without amylose in its endosperm was called ＂waxy wheat＂. Waxy wheat can be used to adjust the amylose content and improve the wheat-based food quality by adding to non-waxy wheat flour. In order to investigate the effect of waxy wheat flour on the quality of fresh and stale bread, waxy wheat flour was added into the flour of Canadian Spring Wheat 2 at 0.0, 5.0, 10.0, 15.0, 20.0, 25.0, 30.0, and 35.0% to make breads. The physicochemical properties were adjusted to suitability by adding Yangmai 158 flour, and breads were evaluated for sensory quality, crumb firmness, loaf volume and weight loss over a period of 0, 2, 4, and 6 days. The result showed that the best total score of fresh bread was 82.9 by adding waxy flour at 7.0%, though no significant difference was found among blends with 0.0-15.0% of waxy flour. Breads with the addition of 22.0% waxy flour had lower firmness, and decreasing loss of weight. Waxy wheat flour blend at 15.0% was optimal in retarding staling without significant decreasing fresh bread quality in comparison to the control.