Bread Wheat Genotypes Research Articles

Heat stress tolerance in wheat seedling: Clustering genotypes and identifying key traits using multivariate analysis

Elevated atmospheric heat is considered as one of the bottlenecks for global wheat production. Screening potential wheat genotypes against heat stress and selecting some suitable indicators to assist in understanding thermotolerance could be crucial for sustaining wheat cultivation. Accordingly, 80 diverse bread wheat genotypes were evaluated in controlled lab condition by imposing a week-long heat stress (35/25 °C D/N) at the seedling stage. The response of heat stress was evaluated using multivariate analysis techniques on 20 morpho-physiological traits. Results showed significant variations in the studied traits due to the imposition of heat stress. Eleven seedling traits that contributed significantly to the genotypic variability were identified using principal component analysis (PCA). A substantial correlation between most of the selected seedling attributes was observed. Hierarchical cluster analysis identified three distinct clusters among the tested wheat genotypes. Cluster 1, consisting of 33 genotypes, exhibited the highest tolerance to heat stress, followed by Cluster 2 (18 genotypes) with moderate tolerance and Cluster 3 (29 genotypes) showing susceptibility. Linear discriminant analysis (LDA) approved that nearly 93 % of the wheat genotypes were appropriately ascribed to each cluster. The squared distance analysis confirmed the distinct nature of the clusters. Using multi-trait genotype-ideotype distance index (MGIDI), all 12 identified tolerant genotypes (BG-30, BD-468, BG-24, BD-9908, BG-32, BD-476, BD-594, BD-553, BD-488, BG-33, BD-495, and AS-10627) originated from Cluster 1. Selection gain in MGIDI analysis, broad-sense heritability, and multiple linear regression analysis together identified shoot and root dry and fresh weights, chlorophyll contents (a and total), shoot tissue water content, root-shoot dry weight ratio, and efficiency of photosystem II (PS II) as the most vital discriminatory factors explaining heat stress tolerance of 80 wheat genotypes. The identified genotypes with superior thermotolerance would offer resourceful genetic tools for breeders to improve wheat yield in warmer regions. The traits found to have greater contribution in explaining heat stress tolerance will be equally important in prioritizing future research endeavors.

Assessment of Heritability and Genetic Advance for Yield and Yield Related Traits under Different Dates of Sowing of Bread Wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is a self-pollinating annual plant extensively grown as staple food source in the world. Information on the extent of heritability and genetic advance among different traits of bread wheat genotypes is essential to designing breeding strategies with the objective to estimate heritability and genetic advance for different characters of bread wheat genotypes. A total of 10 bread wheat genotypes were evaluated for 15 traits sown, three at different dates in 10 days interval The first on 30 November 2022, second on 10 December 2022, and third 20 December 2022 in a Randomized Block Design with three replications at Student Instruction Farm, C.S. Azad University of Agriculture and Technology, Kanpur-208002 (U.P.) during Rabi, 2022-23. in Randomized Block Design. High PCV and GCV were observed from biological yield, grain yield, plant height and productive tiller per plant high heritability estimate were recorded for grain yield per plant followed by biological yield per plant, plant height, days to 50% heading, days to maturity, number of productive tillers per plant, 1000-grain weight and number of grains per ear in both generations on individual and grain yield per plant followed by biological yield, number of productive tillers per plant, plant height, seed hardness, days to maturity in both generations on pooled basis. High genetic advance was observed for grain yield per plant and biological yield per plant in both the generation; seed hardness, number of productive tillers per plant in F1 generation and grain yield per plant and biological yield per plant in both the generation on pooled basis. Consequently, since additive gene action controls the phenotypic manifestation of certain features, those traits should receive special attention in wheat breeding programs. Grain yield will therefore be increased by direct selection for these features.

Characterization of some local and commercial bread wheat (Triticum aestivum L.) genotypes with allele-specific DNA markers

Landraces play a significant role as genetic reservoirs in wheat breeding endeavors. Advances in functional marker technology have facilitated early and more precise selection processes. This study involved the characterization of a total of 96 bread wheat genotypes, comprising 76 landraces and 20 registered cultivars, utilizing allele-specific DNA markers targeting various genes including those for gluten strength, yellow rust resistance, stem rust resistance, dwarfism, rye translocation, hardness, and softness. Molecular analysis revealed the presence of 148 alleles, with an average of 21.14 alleles per marker, and an average polymorphic information content (PIC) value of 0.5625. Specific genes such as the rye translocation gene were identified in genotypes 161 and 884, while the hardness gene was found in genotypes 672, 3088, 3384, 3414, and 3541. Stem rust resistance gene was detected in the cultivar Adana-99, yellow rust resistance gene in genotypes 1635 and 2115, and the softness gene in 31 genotypes including the cultivar Masaccio. Based on the dendrogram analysis, genotype 3652 exhibited around 93% genetic similarity with the cultivar Masaccio, while genotypes 2190, 2715, and 2897 showed similarity to genotype 2946. Genotypes 2959 and 2960 and genotypes 3334 and 3359 shared approximately 91% genetic similarity.

Molecular marker detection of the leaf rust resistance genes Lr34, Lr74, Lr75, and Lr80 and their importance for partial resistance in bread wheat genotypes

Molecular marker detection of the leaf rust resistance genes Lr34, Lr74, Lr75, and Lr80 and their importance for partial resistance in bread wheat genotypes

Evaluation Performance of Genotypes of Bread Wheat Under the Dry Land Conditions of Nineveh Governorate.

Evaluation Performance of Genotypes of Bread Wheat Under the Dry Land Conditions of Nineveh Governorate.

Identification of bread wheat (Triticum aestivum L.) genotypes tolerant to heat and low N stress

Identification of bread wheat (Triticum aestivum L.) genotypes tolerant to heat and low N stress

Utilizing Infrared Thermometry to Assess the Crop Water Stress Index of Wheat Genotypes in Arid Regions under Varying Irrigation Regimes

Researchers are depending more than ever on remote sensing techniques to monitor and assess the agricultural water status, as well as to estimate crop water usage or crop actual evapotranspiration. In the current work, normal and stressed baselines for irrigated wheat genotypes were developed in an arid part of the Sohag governorate, Egypt, using infrared thermometry in conjunction with weather parameters. The experiment was carried out in a randomized complete block design in the normal and drought stress conditions based on three replicates using ten bread wheat genotypes (G1–G10), including five accessions, under drought stress. A standard Class-A-Pan in the experimental field provided the daily evaporation measurements (mm/day), which was multiplied by a pan factor of 0.8 and 0.4 for normal and stressed conditions, respectively. The relationship between the vapor pressure deficit (VPD) and canopy-air temperature differences (Tc − Ta) was plotted under upper (fully stressed) and lower baseline (normal) equations. Accordingly, the crop water stress indexes (CWSIs) for the stressed and normal baselines for wheat genotypes were developed. Additionally, the intercept (b) and the slope (a) of the lower baseline equation were computed for different genotypes. The results indicate that, before applying irrigation water, the CWSI values were high in both growing seasons and under all irrigation regimes. After that, the CWSI values declined. G10 underwent stress treatment, which produced the greatest CWSI (0.975). Conversely, the G6 condition that received well-watered irrigation yielded the lowest result (−0.007). When compared to a well-watered one, the CWSI values indicated a trend toward rising stress. There existed an inverse link between the CWSI and grain yield (GY); that is, a lower CWSI resulted in better plant water conditions and a higher GY. Under standard conditions, the wheat’s highest GY was recorded in G2, 8.36 Ton/ha and a WCSI of 0.481. In contrast, the CWSI result for the stress treatment was 0.883, indicating a minimum GY of 5.25 Ton/ha. The Water Use Efficiency (WUE) results demonstrated that the stress irrigation regime produced a greater WUE value than the usual one. This study makes a significant contribution by investigating the techniques that would allow CWSI to be used to estimate irrigation requirements, in addition to determining the irrigation time.

Multivariate Analysis Techniques and Tolerance Indices for Detecting Bread Wheat Genotypes of Drought Tolerance

Drought stress is one of the biggest hardships in wheat cultivation because of the strong negative relationship between water deficit and crop yields owing to a lower grain weight, a shorter grain-filling period, a slower grain-filling rate, and reduced grain quality. Genotype–environment interaction (GEN:ENV) generates hardships in selecting wheat genotypes and ideotypes due to biased genetic estimates. Diverse strategies have been proposed to respond to the urgent need for concurrent improvements in yield performance and stability. This study’s purpose was to appraise genetic variation and GEN:ENV effects on yield and yield components to discover drought-stress-tolerant genotypes and ideotypes. This study evaluated 20 genotypes in three consecutive seasons under non-stressful and drought-stress conditions in a total of six ENVs. The broad-sense heritability ranged from 0.54 to 0.82 based on expected mean squares and ranged from 0.60 to 0.90 based on plot mean, but in the other three ways, it was usually greater than 0.90. The high values of (σgen:env2) revealed the effect that broad-sense heritability has on the expression of traits. G01, G03, G06, G07, G08, G10, G12, G13, G16, G17, and G18 were stable genotypes for grain yield (GY), according to additive main effects and a multiplicative interaction biplot for the six ENVs. Based on scores in the weighted average of absolute scores biplot (WAASB), G02, G04, G05, G08, G10, and G18 were selected as stable and high-performance for GY, and they were all selected as the best genotype groups using the WAASB-GY superiority index. From the results obtained from principal component analysis and hierarchical clustering and from the tolerance discrimination indices, G02, G04, G05, G18, and G19 are genotypes that produce a suitable yield under non-stressful and drought-stress conditions. In essence, combining approaches that take into consideration stability and high performance can contribute significantly to enhancing the reliability of recommendations for novel wheat genotypes.

Multivariate analysis of phenotypic diversity elite bread wheat (Triticum aestivum L.) genotypes from ICARDA in Ethiopia

Wheat is an important crop for food security, providing a source of protein and energy for the growing population in Ethiopia. However, both biotic and abiotic factors limit national wheat productivity. The availability of genetically diverse wheat genotypes is crucial for developing new wheat varieties that are both high-yielding and resilient to stress. Therefore, this field trial aimed to assess phenotypic variation and relationship among ICARDA-derived bread wheat genotypes using multivariate analysis techniques. The trial was conducted at three locations: Enewari, Wogere, and Kulumsa using an alpha lattice design with two replications during the main cropping seasons of 2022 and 2023. Phenotypic data on eight agronomic traits and the severity of yellow rust were collected and R programming was used for data analysis. Individual and combined location data analysis of variance showed significant differences (p ≤ 0.05) among genotypes for most of the studied traits. The highest heritability and genetic advance as a percentage of the mean were observed in days to heading (90.8, 21.29), plant height (72.4, 28.6), seeds per spike (61.7, 28), thousand kernel weight (61.9, 12), and area under the disease progress curve (67, 39.8), suggesting a predominance of additive gene action. Grain yield showed a strong positive correlation with days to maturity, plant height, spike length, spikelet per spike, and thousand kernel weight for each location. Dendrogram and phylogenetic tree methods were used to group genotypes into four genetically distinct clusters. Cluster II and III had the greatest inter-cluster distance, indicating higher diversity among their genotypes. This study identified new candidate genotypes with superior agronomic performance, high grain yield traits, and robust resistance to yellow rust, making them valuable for both current and future wheat breeding programs. Additionally, the comprehensive dataset produced in this study could facilitate the identification of genetic variations influencing desirable traits through genome-wide association analysis.

Trade-offs between grain number, grain weight and fruiting efficiency of different bread wheat genotypes in response to anthesis drought stress

Cereal crops in Morocco are mainly cultivated under rainfed conditions of dryland regions. Under these conditions, they are mostly exposed to drought stress that affects different yield components. We studied the effect of anthesis drought stress on the relationships among the components of grain number (GN), thousand grains weight (TGW), fruiting efficiency (FE) and yield. And we examined fruiting efficiency (FE= grains set per g of spike dry weight at anthesis) as promising trait for further increasing yield without compromising yield components. Greenhouse experiments were conducted on 2019/2020, 2020/2021 and 2021/2022 cropping seasons. Two contrasting water regimes, irrigated and stressed treatments at anthesis growth stage were assessed. Results showed that anthesis drought stress affects negatively all components studied. Substantial decrease of 10%, 16%, 9% and 34% were recorded for GN, TGW, FE, and yield, respectively, under water stress compared to irrigated treatments. Two genotypes, namely 15/42 and Achtar, were found to be the most adapted to both stressed and irrigated conditions. Under stressed conditions yield becomes less correlated with GN (r = 0.36) and FE (r = 0.37) and more correlated with TGW (r = 0.56*). GN becomes less correlated with FE (r = 0.02) and TGW (r = -0.14). While, FE becomes more correlated with TGW (r = 0.73*). To the extent of this study, FE was found as promising selection criterion under stress conditions without compromising TGW component.

Source-sink relationships during grain filling in wheat in response to various temperature, water deficit, and nitrogen deficit regimes.

Grain filling is a critical process for improving crop production under adverse conditions caused by climate change. Here, using a quantitative method, we quantified post-anthesis source-sink relationships of a large dataset to assess the contribution of remobilized pre-anthesis assimilates to grain growth for both biomass and nitrogen. The dataset came from 13 years of semi-controlled field experimentation, in which six bread wheat genotypes were grown at plot scale under contrasting temperature, water, and nitrogen regimes. On average, grain biomass was ~10% higher than post-anthesis above-ground biomass accumulation across regimes and genotypes. Overall, the estimated relative contribution (%) of remobilized assimilates to grain biomass became increasingly significant with increasing stress intensity, ranging from virtually nil to 100%. This percentage was altered more by water and nitrogen regimes than by temperature, indicating the greater impact of water or nitrogen regimes relative to high temperatures under our experimental conditions. Relationships between grain nitrogen demand and post-anthesis nitrogen uptake were generally insensitive to environmental conditions, as there was always significant remobilization of nitrogen from vegetative organs, which helped to stabilize the amount of grain nitrogen. Moreover, variations in the relative contribution of remobilized assimilates with environmental variables were genotype dependent. Our analysis provides an overall picture of post-anthesis source-sink relationships and pre-anthesis assimilate contributions to grain filling across (non-)environmental factors, and highlights that designing wheat adaptation to climate change should account for complex multifactor interactions.

Screening of bread wheat genotypes for identification of novel stripe rust resistance genes using molecular markers

Stripe Rust, caused by Puccinia striiformis Westend f. sp. tritici , is an important fungal disease of wheat worldwide. In this study, 41 wheat genotypes from various institutes across India were screened for adult plant resistance (APR) in field trials, and the presence of effective stripe rust resistance genes was evaluated in the laboratory using ten molecular markers.The bread wheat variety Agra local was used as a susceptible control. Molecular characterization studies revealed that the gene Yr 2 was found in 29 entries, Yr5 in 15 entries, Yr9 in 7 entries, Yr10 in 18 entries, Yr15 in 18 entries, Yr17 in 12 entries, Yr18 in 29 entries, Yr36 in 21 entries, Yr40 in 31 entries while Yr65 was absent in all the entries. The genotypes PBW780 and High Rainfall Wheat Screening Nursery (HRWSN) line 2105 had seven Yr genes conferring resistant phenotypes, suggesting that these were excellent sources of effectual stripe rust resistance. The coefficient of infection showed adequate genotypic variations for rust severity, 41 genotypes showed year-specific responses, suggesting strong G × E interactions.

Genome-wide association and genomic prediction study of elite spring bread wheat (Triticum aestivum L.) genotypes under drought conditions across different locations

Abiotic stress, notably drought, impacts wheat production globally, but more so in central and South Asia, North Africa (CWANA), and sub-Saharan Africa (SSA). The current study attempts to identify significant markers linked to drought and heat tolerance and assess genomic prediction. A genome-wide association study was conducted using the 10 K wheat SNP markers for grain yield and related traits of 246 spring bread wheat genotypes from ICARDA. Traits including grain yield (GY), days to heading (DHE), days to maturity (DMA), plant height (PLH), and thousand kernel weight (TKW), were evaluated across six different locations, spanning two years 2015–2016 and 2016–2017, as per variance analysis. Grain yield and related-traits showed a considerable variation among genotypes. Moreover, GWAS using a mixed linear model (MLM), revealed 65 marker-trait associations (MTAs) across the six environments on 16 chromosomes. With an average r2 value of 0.26, Genome D has the highest linkage, followed by Genomes B and A with r2 values of 0.22 and 0.21, respectively. GY had the highest MTA rating (35), followed by TKW (9) and 3 for each of the other agronomic traits (DHE, DMA, PLH) at Merchouch station. The marker “CAP8_c1393_327” was the most significant associated marker correlated with grain yield located on chromosome 3 A across Sid El Aidi station. Additionally, the SNP markers “wsnp_Ra_c26091_35652620” displayed extremely significant and stable MTA for TKW on chromosome 5B at Merchouch station. The markers and candidate genes reported throughout this study have the potential to be used in marker-assisted selection to enhance wheat genotypes in terms of yield and resistance to drought limitations.

Performance Several Genotypes of Bread Wheat (Triticum aestivum L.) Under Effect Spraying with Glutamic Acid and Arginine (Growth and Yield Traits)

Performance Several Genotypes of Bread Wheat (Triticum aestivum L.) Under Effect Spraying with Glutamic Acid and Arginine (Growth and Yield Traits)

Spraying Different Combinations of Glutamate and Arginine on Yield Traits and Components of Several Genotypes of Bread Wheat (Triticum aestivum L.)

Spraying Different Combinations of Glutamate and Arginine on Yield Traits and Components of Several Genotypes of Bread Wheat (Triticum aestivum L.)

Genetic variability and trait associations in bread wheat (Triticum aestivum L.) genotypes under drought-stressed and well-watered conditions

Drought is one of the most important yield-limiting abiotic stresses threatening wheat production and productivity. Development of wheat genotypes with enhanced grain yield under drought-stressed conditions depend on the extent of genetic variation present for drought tolerance-related traits. This study was carried out to determine the level of genetic variation and associations of yield and yield attributing traits among 196 bread wheat genotypes under drought-stressed and well-watered conditions. The genotypes were evaluated under greenhouse and field conditions and phenotyped for yield and yield-related traits. The genotypes varied significantly for the traits under both conditions. Grain yield ranged from 2.13 to 3.74 t ha−1 and from 2.52 to 5.06 t ha−1 under drought-stressed and well-watered conditions, respectively. Under both conditions, variances due to genotype were higher than environment and genotype × environment interaction variances for all the traits. Estimates of phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the traits under both conditions, with both PCV and GCV being highest for kernel weight spike−1 and lowest for spike fertility. Under both conditions, broad-sense heritability estimates ranged from moderately high to very high, accompanied with high genetic advance as a percentage of the mean. Fertile spikelets spike−1, one thousand kernel weight, kernel weight spike−1, biomass yield and harvest index manifested high positive genotypic and phenotypic correlations and positive direct effects on grain yield under both conditions. The first five principal components accounted for 78.4% (well-watered) and 76.0% (drought-stressed) of the variation among the genotypes. The 196 genotypes were delineated into six major clusters under both water conditions, with clusters 3 (well-watered) and cluster 5 (drought-stressed) containing genotypes with the highest ability to tolerate drought stress. Genotypes Alidoro, Bolo, Dinknesh, ETBW8491 and ETBW172938 had high stable yields under both conditions. The identified traits and genotypes were drought tolerant and could be exploited to develop novel genotypes for drought stress tolerance.

Estimates of Genetic Parameters, Combining Abilities and Heterosis for some Genotypes of Bread Wheat

Estimates of Genetic Parameters, Combining Abilities and Heterosis for some Genotypes of Bread Wheat

Multi-environments Evaluation of Zn and Fe Enhanced Bread Wheat Genotypes in Optimum Areas of Ethiopia

A multi-location experiment was conducted during June, 2020–October, 2021 under rainfed condition at Kulumsa, Asasa, Adet, Holeta, and Sinana Research centers, Ethiopia to evaluate the genotype-by-environment interaction effect and grain yield stability of Zn and Fe enhanced bread wheat genotypes grown. The treatments constituted 21 advanced genotypes and two standard checks were evaluated in an alpha lattice design replicated three times and data analysis was carried using R software. The results showed that genotypes and genotype x environmental interaction had a significant (p<0.001) effect on days to 50% heading, days to 90% maturity, plant height, grain yield, and 1000 kernel weight. The bread wheat lines BW172862, EBW193416, BW172864, and EBW193414 were high-yielding across most test environments, whereas genotype EBW192455 and Hidasse were low-yielding ones. From stability analysis genotypes BW172862, and EBW193416 were identified to be the most adapted bread wheat genotypes. “BW172862 produced 24.43% and 86.38% yield advantage over the standard check (Lemu) and local check (Hidasse), respectively. The second candidate genotype EBW193416 also produced 23.58% and 85.1% yield advantage over the standard check (Lemu) and local check (Hidasse), respectively. EBW193416 and BW172862 have also exhibited lower Yellow and Stem rust severity compared to others across the test environments. Thus, BW172862 and EBW193416 were selected as best parent to recycle for bread wheat population improvement in 2023 for medium agro-ecology of Ethiopia.

Proximal canopy sensing of twenty-two bread wheat genotypes for nutritional quality, yield attributes and grain yield under Mediterranean climate

To ensure nutritional security of rapidly increasing population, research interest has revitalized in determining the nutritional quality traits of staple food crops, especially wheat. Besides higher yield potential, research gaps exist regarding nutritional quality assessment of promising wheat genotypes grown under the Mediterranean climate. A field study was conducted to determine the relationship between yield components and quality characteristics of 22 bread wheat genotypes using the SPAD meter, GreenSeeker (NDVI), and CM-1000 chlorophyll meter at different growing stages (Stem elongation, Heading, Anthesis and Milk stage). The recorded findings revealed that G-41 genotype surpassed the rest of bread wheat genotypes by recording the maximum grain yield, whereas G-60 genotype exhibited the highest protein and wet gluten content. Among response variables, SPAD and NDVI values at the heading stage and CM-1000 values at the milk stage were found to be statistically insignificant. According to the correlation and biplot analysis, a significant positive correlation was found between the SPAD values measured for the stem elongation, anthesis and milk stage and yield and quality characteristics. Significant positive correlations were found between the NDVI values at the stem elongation, anthesis, and milk stages and the yield components, and between the CM-1000 value at the heading stage and the grain yield.

The Effect of Different Protein Ratios on Other Quality Parameters in Bread Wheat Genotypes

The Effect of Different Protein Ratios on Other Quality Parameters in Bread Wheat Genotypes