Gamma irradiation–induced variation in grain protein content and days from sowing to heading in M₅ mutant lines of spring wheat (cv. Eritrospermum-35)

Exploring genetic diversity and stress adaptation in bread wheat (Triticum aestivum L.) under terminal heat stress

Genotype evaluation and profiling of bread wheat (Triticum aestivum L.) using a genotype-by-yield-traits (GYT) approach under rain-fed conditions: implications for breeding

Estimation of Genetic Parameters and Character Associations, and Disease Resistance of Bread Wheat (Triticum aestivum L.) Genotypes

The experiment was conducted during July–November in 2023 main cropping season at Kulumsa Agricultural Research Center  to assess the extent of genetic variability and the association among traits in bread wheat genotypes. Analysis of variance revealed significant genetic variation (p<0.01) among genotypes for seven of the nine studied characters. Grain yield exhibited the widest range, varying from 891(EBW232651) to 1682.5 (EBW232625) kg ha-1, with an average of 1325.96 kg ha-1. Encouragingly, 78% of studied genotypes exhibited superior grain yield compared to check Balcha (1242.5 kg ha-1). A moderate range of PCV and GCV were obtained for agronomic score, grain yield and thousand kernel weight, offer the most significant potential for improvement through selection. The high broad-sense heritability observed for days to heading days to maturity, hectoliter weight and thousand kernel weight, and traits with high GAM viz. grain yield and agronomic score, suggested a significant role of additive gene action in controlling these traits. Grain yield exhibited strong positive and highly significant correlations (p<0.01) at both genotypic (rg) and phenotypic (rp) levels with Agronomic Score, Thousand kernel weight and hectoliter weight. Grain yield displayed a strong negative and highly significant correlation (p<0.01) at both genotypic and phenotypic levels with yellow rust severity. The negative correlation with yellow rust severity emphasized the need to prioritize resistance breeding to protect yield potential from this disease. This finding suggested that selecting for improved agronomic score, hectoliter weight, and thousand kernel weight could be effective indirect selection strategies for enhancing grain yield in this breeding population.

Assessment of Genetic Variability, Heritability and Genetic Advance for Yield and Yield-contributing Traits in Bread Wheat (Triticum aestivum L.)

Genetic variability is the foundation of effective selection and crop improvement in wheat breeding programmes. Therefore, the present investigation was conducted during the Rabi season of 2023–24 at the Crop Research Centre, Jigyasa University, Dehradun, Uttarakhand, to evaluate genetic variability, heritability and genetic advance for yield and yield-contributing traits in bread wheat (Triticum aestivum L.). Thirty wheat genotypes were evaluated in a randomized block design with three replications. Observations were recorded for fifteen quantitative characters, including phenological traits, plant height, flag leaf area, productive tillers per plant, spike traits, grains per spike, 1000-grain weight and grain yield per plant. Analysis of variance revealed significant differences among genotypes for plant height, flag leaf area, grains per spike, 1000-grain weight, grain filling period, days to maturity and days to 50% heading, indicating the presence of substantial genetic variability for these traits. The phenotypic coefficient of variation was slightly higher than the corresponding genotypic coefficient of variation for all characters, suggesting a limited influence of environmental factors on trait expression. High heritability estimates were observed for plant height, flag leaf area, grains per spike, 1000-grain weight, spike weight per plant and grain yield per plant. Among these, plant height and flag leaf area also exhibited comparatively higher genetic advance as percent of mean, indicating their potential for effective improvement through selection. The findings suggest that these traits may serve as reliable selection criteria for developing high-yielding bread wheat genotypes under the agro-climatic conditions of the study area.

Genetic Variability and Performance of Bread Wheat (Triticum aestivum L.) Genotypes under High Temperature Environments of Ethiopia

This study was conducted during May to December, 2022 at Kulumsa and Melkassa, in Ethiopia, evaluated 49 CIMMYT-introduced genotypes including the check variety across two locations using an alpha lattice design. The Combined analysis of variance revealed highly significant genetic variability for most of the traits, including grain yield (GYLD), thousand kernel weight (TKW) and hectoliter weight (HLW).Genotypes EBW222059, EBW222088 and EBW222079 were the top yielders, consistently outperforming the check. High genotypic (GCV) and Phenotypic (PCV) coefficients of variation for GYLD (22.24% and 24.42%) and TKW (13.38% and 15.32%) at Kulumsa indicated a strong genetic base for improvement. Very high broad-sense heritability for grain yield (83%) and days to heading (92%), coupled with high genetic advance as a percent of mean (GAM) for grain yield (41.72%), suggested the predominance of additive gene action, making phenotypic selection highly effective. However, maturity traits and plant height showed significant environmental influence, rendering direct selection for these traits ineffective. Correlation analysis confirmed that grain yield was strongly and positively associated with TKW and HLW at both genotypic and phenotypic levels. These results demonstrated that selecting for heavier, denser grains was a reliable strategy for yield enhancement. The study concluded that the identified elite genotypes should advance to multi-environment stability trials, while TKW and HLW should be prioritized as key selection markers to accelerate the development of high-yielding, adaptable wheat varieties. Thus, genetic variability in these genotypes could be exploited to enhance bread wheat yields under high-temperature conditions of Ethiopia.

Genotypic variability and heritability of agronomic traits in chemically mutagenized groundnut (Arachis hypogaea L.)

It is crucial to know the heritable portion of variation as it provides variability component measure for the transmission of characters to the next generation. This study was aimed at the estimation of genotypic variability for agronomic traits in chemically mutagenized groundnut (Arachis hypogea L.) genotypes. Although groundnut ranks second among oil seed crops in the world after sun flower and also an excellent source of protein, carbohydrates minerals and antioxidant, the production in Nigeria is constrained by multiple factors including low genetic variability which impact the development of high-yielding varieties. Pot trials were carried out during 2025 and 2026 dry seasons under screen house at the teaching and research field, Department of Plant Science and Biotechnology, Bayero University, Kano. The seeds of the two improved groundnut genotype varieties (Samnut-24, Samnut-25) were collected from Kano State Agricultural and Rural Development Authority (KNARDA) and the two local varieties (’Yar-Gingo and ’Yar-Fara) were collected from Dawanau Market, Dawakin Tofa Local Government  Kano State. The experimental design used was Complete Randomized Design (CRD) and the seeds of each variety were sorted out and surface sterilized in 2.0% Sodium hypochloride for 1minute and then rinsed. The seeds were soaked in different concentrations of Hydroxyalamine Hydrochloride (0.00mM, 1.0mM, 2.0mM, 3.0mM and 4.0mM) or Sodium Azide (0.00mM, 1.0mM, 2.0mM 3.0mM and 4.0mM) for three (3) hours.  The results revealed significant variation among the genotypes. Genotypic (GCV %) coefficient of variation was observed lower than the phenotypic coefficient of variation (PCV %) for all the observed traits in this study, indicating that the environment significantly affect the expression of the traits. In Samnut-24 genotype, high genetic advance (GA) along with high heritability (H2) were observed in 100 Pod Weight and Biological Yield. Similarly, 100 Pod Weight of Samnut-25 genotype scored highest genetic advance (GA) of (32.95) and heritability (H2) of (61.92%) indicating genetic improvement through direct genotypic selection. It is recommended that, farmers should adopt the use of genotypes with expressed additive gene action developed from variable components for crop improvement.