Field pea is one of the important short-duration cool season pulse crops which contributes significantly towards food and nutritional security. Two heat-susceptible (HS) and two heat-tolerant (HT) genotypes were selected from the previous study for further characterization. A significant variation was observed for morpho-physiological traits studied. Principal component analysis explained that first two principal components, i.e., PC1 and PC2 showed 76.5% of the total variance in optimal condition, whereas 91.2% of the total variance was covered by the first two PCs in heat stress environment. The seed yield per plant determined significant and positive association with superoxide dismutase and number of seeds per pod under optimal conditions, whereas under heat stress condition, it was positively associated with number of effective pods per plant, biological yield per plant, proline, pod length, number of seeds per pod, superoxide dismutase, and peroxidase. The significant reduction was noticed in the susceptible genotypes, whereas tolerant genotypes showed stable and non-significant reduction in chlorophyll content. Further, minimum cell damage and higher hydrogen peroxide production was noticed in the susceptible genotypes. In addition, the biochemical characterization of HS and HT genotypes revealed that the higher expression of peroxidase, superoxide dismutase, and catalase modulates the tolerant responses in HT genotypes. These genotypes were further used in developing heat-tolerant field pea genotypes.

Eight field pea parental lines and their twenty-eight F₁s resulting from diallel design (excluding reciprocal) were analyzed for their combining ability and heterosis for yield and associated traits. ANOVA revealed significant variation among parents and among hybrids for days to 50% flowering, plant height, total number of pods, effective pods, seeds per pod, 100-seed weight, biological yield and seed yield; pod length also revealed significant differences among hybrids, suggesting the occurrence of considerable variability for studied traits. Crosses P-1541-16 × P-92-97-11 and P-1541-16 × P-1297-97 displayed significant heterosis over better-parent and control varieties for seed yield and associated traits. Combining ability analysis showedthat SCAvariance was considerably higher than corresponding GCAvariance for all traits. Genotype Aman and P-1297-97 were identified as good general combiners for seed yield, while cross P-1541-16 × P-1297-97, Aman × EC-564817, P-1541-16 × P-92-97-11 and P-1297-97 × P-92-97-11 were identified as specific cross-combiners for most of the studied traits. Consequently, these crosses might be exploited in future breeding programs to find desired segregants. PCA explained 81.68% and 83.34% variability in parents and crosses, respectively, for yield component. Furthermore, trait association between GCA effects and SCA effects demonstrates that biological yield, total number of pods, and effective pods exhibit additive gene action, but 100-seed weight exhibits non-additive gene action.

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An experiment was conducted to study the effect of phytohormones (auxin and cytokinin) in mitigation of drought stress on pairs of contrasting genotypes of wheat i.e. tolerant (DBW 110 and HI 1655) and susceptible (BW Local 1 and BW Local 2) at seedling stage under four conditions. Drought was induced by PEG 6000. It was observed that phytohormones had a significant role in mitigating stress by adjusting growth parameters, physiological parameters, reactive oxygen species level and antioxidants activity. Application of auxin and cytokinin leads to desirable changes in shoot length (2.36 and 3.26), root length (1.21 and 1.17), seedling length (2.36 and 2.74), fresh shoot weight (1.24 and 1.28), fresh root weight (1.41 and 1.21), fresh seeding weight (3.37 and 4.19), total chlorophyll (1.72 and 1.63), maximal quantum yield of photosystem II (1.51 and 1.70), stomatal conductance (1.38 and 1.19), catalase activity (4.75 and 5.68), ascorbate peroxidase activity (14.63 and 18.05) and proline content (1.37 and 1.28) and hydrogen peroxide content (1.22 and 1.31) represented in average folds as compared to control. Fresh seedling weight showed positively significant correlation with fresh shoot weight (r=1.00**), shoot length (r=1.00**), catalase (r=0.99*), ascorbate peroxidase (r=0.99*), seedling length (r=0.98*), total chlorophyll (r=0.97*) and negative and significant correlation with hydrogen peroxide (r=-1.00**) under effect of auxin whereas it showed positively significant correlation with fresh shoot weight (r=1.00*), chlorophyll b (r=0.98*), stomatal conductance (r=0.98*), maximal quantum yield of photosystem II (r=0.97*), total chlorophyll (r=0.96*), chlorophyll a (r=0.95*), fresh root weight (r=0.95*) and significant and negative correlation with hydrogen peroxide (r=-1.00*) under effect of cytokinin indicating that these are the important traits targeted by the phytohormones to mitigate the stress. Biplot analysis revealed that traits were grouped as positively correlated (all traits except H2O2) and negatively correlated (H2O2) to the drought tolerance. Study concluded that application of auxin and cytokine can minimize yield reduction of susceptible high yielding genotypes under drought stress. Further study under natural stress is required to understand the mechanism of phytohormones in mitigation of drought.

Background: Field pea is an important cool season grain legume crop. This study was conducted on field pea to explore phenotypic and molecular diversity among field pea genotypes, catering to current and future crop improvement. Methods: In this investigation forty-six genotypes of field pea were evaluated in randomized block design to assess phenotypic diversity for morphological and quality traits, alongside molecular characterization using simple sequence repeat (SSR) markers. Result: Variability analysis displayed substantial variability for all traits among test genotypes. Cluster analysis grouped the all genotypes into three distinct multi-genotypic clusters with clusters II and III having highest inter-cluster distance. Molecular characterization revealed the detection of 43 repeatable alleles by 14 polymorphic SSR markers, spanning a size range of 150 bp (AA122) to 970 bp (AA504), with a maximum of 4 fragments intensified by AD147, D21, AA504, AA122 and A9. Utilizing Jaccard dissimilarity coefficients and UNJ methods, all forty-six genotypes were grouped into three clusters. This study on field pea facilitates the identification of diverse parent selections capable of producing desirable segregants in future breeding programs.