Rice typically has poor germination under submerged conditions, but some landraces can germinate underwater, which provides valuable resources for investigating the genetic and physiological mechanisms behind these characteristics. This study evaluated 500 rice genotypes, including tolerant and susceptible genotypes for anaerobic germination tolerance. Only 100 genotypes germinated under anaerobic conditions, showing significant variation in germination percentage (30–85

As erratic rainfall and flooding pose serious threats to rice yields, submergence tolerance is critical for sustainable cultivation. This study screened 250 Indian rice landraces at the seedling stage to identify genotypes capable of surviving submergence stress. Advanced statistical analyses, including trait association, variability, principal component analysis and cluster analysis, revealed the genetic and phenotypic factors influencing submergence stress tolerance. Significant variability was observed among the genotypes for key traits, such as shoot elongation, leaf regeneration and survival percentage. Diversity analysis through cluster analysis indicated that cluster III, particularly IRGC93, IRGC535 and IRGC706, exhibited survival rates exceeding 85%, highlighting their potential as donor lines for submergence tolerance. Further biochemical analysis of selected lines with survival percentages greater than 50% revealed that tolerance is associated with greater chlorophyll and non-structural carbohydrate retention percentages. The findings emphasize the importance of genetic variability and heritability in breeding resilient rice varieties for flash flooding conditions. This research contributes to advancing rice breeding strategies to produce submergence-tolerant varieties, thereby promoting the sustainability and productivity of paddy production systems.

The pulse beetle, Callosobruchus spp., poses a threat to legumes by consuming the protein content of the grain, resulting in potential losses in storage ranging from 12 to 30%. Molecular marker technology helps to mitigate the breeding constraint in the development of bruchid resistance in green gram breeding programmes. In the present study, validation of locus-specific STSbr1 and STSbr2 markers linked with bruchid resistance was done using fifteen genotypes viz., VBN (Gg) 2 (susceptible) and Vigna radiata var. sublobata/2 (resistant), F1 hybrid, two susceptible and ten resistant RILs derived from the above parents. The marker STS br1 behaved as a dominant marker and produced an approximate allele size of 225 bp in the resistant parent, F1 hybrid and resistant RILs and absent in susceptible parent and susceptible RILs, which showed cent per cent co-segregation with bruchid resistance locus. Hence, it is concluded that STS br1 is linked with bruchid-resistant genes. The marker STS br2 behaved as a co-dominant marker and produced an approximate allele size of 470 bp in all the 15 genotypes evaluated (monomorphic) and did not differentiate the resistant and susceptible genotypes. The marker STS br1 could be used in marker-assisted selection to develop bruchid-resistant varieties and to screen the germplasm to identify bruchid-resistant donors in green gram.

Background: Visual polymorphism of the seeds is supposed to play an important role in breeding programme. Hence this study helps to estimate the genetic parameters in pre breeding lines of blackgram. Methods: One hundred and eighty nine pre breeding lines obtained from the cross VBN (Bg) 5 × Vigna mungo var. silvestris were evaluated during kharif, 2019 and rabi, 2019-20 in a replicated trial. The seed related traits such as seed length, seed width, thickness, length width ratio, seed volume, bulk density and hundred seed weight were taken for analysis. Result: The values of PCV were higher than the GCV indicating the environmental influence over these traits. Moderate GCV was observed for seed volume (13.03%) and hundred seed weight (10.55%). Low GCV was observed for length width ratio (5.21%), seed width (4.47%), bulk density (4.08%), seed thickness (3.54%) and seed length (2.96%). The difference between PCV and GCV was high for seed volume (6.84) followed by seed thickness (2.03) indicating the higher environmental influence over these traits. High heritability was noticed for the traits viz., hundred seed weight (96.22%), seed width (96.03%), length width ratio (93.13%), bulk density (91.13%) and seed length (88.11%). High heritability along with high genetic advance as per cent of mean was observed for hundred seed weight (96.22 and 21.32 respectively) which defines the additive gene action that would help in the selection of these traits. Correlation analysis revealed that bulk density, seed thickness, seed volume, seed length and seed width had significant and positive correlation with hundred seed weight. Seed thickness and bulk density had high direct effect on hundred seed weight. Thus, results from the present study could be used to obtain bold seeded variety in blackgram.

Complete submergence is one of the most important abiotic stress constraining rice production in India. From the past few decades effect of this stress has intensified and is anticipated to increase in coming years as a result of global climate change. Rice has developed many adaptive mechanisms to grow well in flood ecosystems however, too much water for long time at any stage of plant growth can lead to serious injuries like decaying of plant parts, lodging and reperfusion causing total crop loss. Because of these conditions, farmers usually rely on traditional landraces that can survive through this stress, despite the fact that these tends to be very low yielding. In the present study, 660 rice landraces along with checks were subjected to screening for submergence tolerance at vegetative stage in target production environment. Identification of tolerant genotypes was based on the survival percentage of plants and recovery by which they grown new tillers and leaves. Principle component analysis revealed three principle components accounted for 99.9 per cent of total variation. Regeneration percentage of tillers found to be the most discriminating character and possess additive gene action. Confirmation through cluster analysis grouped the tolerant and susceptible genotypes in the respective clusters. Results of screening showed that, out of 660 accessions, three accessions viz., IC388692, IC377169 and IC205953 have highest tolerance to 14 days of submergence and the survival ability was similar to the tolerant checks FR13A and CO 43-Sub1. Apart from the above three accessions, eight accessions viz., IC216378, IC126210, IC114413, IC386238, IC133584, IC114971, RL-1312 and RL-3055 scored 1 for faster regeneration of tillers denoting the ability to have good tolerance for submergence stress.

Mango (Mangifera indica. L) is characterized by a high level of genetic variation in seedling population. Estimation of genetic advance is required for the expected genotypic progress of a particular character. Keeping this in view, genetic advances of year-round flowering mango (Mangifera indica. L) genotypes was carried out during 2019-2021 in farmer’s field at Annur, Coimbatore. High Genotypic Coefficient of Variation (GCV) was found in fruit yield per tree was 30.63 per cent. The low GCV values were found for the traits viz., panicle length (6.61 %), days taken for flowering to fruit set (1.75%), days taken for flowering to fruit maturation (1.76 %), percentage of hermaphrodite flowers (5.38 %), sex ratio (5.18%). Whereas high values of heritability estimates were obtained for the traits viz., fruit yield per tree (99.43 %), number of panicles/tree (98.91 %), number of fruits per tree (97.74 %), panicle per sq.m of canopy (97.40 %). The high heritability along with high genetic advance as per cent of mean was observed for fruit yield per tree (99.43, 62.91), number of panicles/tree (98.91, 46.84), number of fruits per tree (97.74, 43.03), panicle per sq.m of canopy (97.40, 28.64) indicates the possibility of improving these traits by selection since there is a wide range of variation and additive gene action exists for these traits. The traits viz., panicle per sq.m of canopy, panicle length, number of panicles/tree, sex ratio, number of fruits per tree were positively correlated with fruit yield per tree. Hence, the selection for these characters would improve fruit yield in mango.

The present study was carried out using 189 pre-breeding lines from the cross VBN (Bg) 5 and Vigna mungo var silvestris 22/10 to study the genetic variability for nine yields and six seed traits. Significant variability was observed for all the traits studied. The phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all the 15 traits. High PCV was observed for number of pods per plant, seed volume, and single plant yield. The moderate to high GCV was exhibited for hundred seed weight, plant height, number of pods per plant, seed volume, and single plant yield. The heritability estimates were high for pod length, plant height, seed length, hundred seed weight, single plant yield, bulk density, seed length-width ratio and seed width. The traits viz., plant height, hundred seed weight, and single plant yield showed high heritability along with high genetic advance as per cent of mean respectively, which might be due to additive gene action. Hence, these traits could act as a better source for the breeding programme for evolving high-yielding bold seeded varieties.

Cowpea {Vigna unguiculata (L.) Walp.} is one of the most important food legumes in the semi arid tropics which encompass Asia and Africa. Thirty genotypes of cowpea were used to study molecular genetic diversity using nineteen cowpea specific SSR markers. Among 19 SSR markers, 13 markers exhibited polymorphism and two markers showed monomorphic banding pattern. Four markers produced multiple alleles. A total of 33 alleles were generated. The number of alleles produced by different markers ranged from one to three with an average of 2.2 alleles per marker. Cowpea specific markers viz., VM25,VM35,VM 36,VM5 and CP 1 produced the highest number of alleles (3).The Polymorphism Information Content (PIC) ranged from 0.585 (VM 5) to 0.064 (VM 19) with an average of 0.368. SSR marker data analysis showed high dissimilarity among the 30 cowpea genotypes. The genotypes VCP 9-009 with CP 2-1, KB CP 39 and K 13 CP 25 had the highest dissimilarity index value and showed the extent of genetic diversity existed among the genotypes. A dendrogram constructed using unweighted pair group method using arithmetic average (UPGMA) analysis distinguished 30 genotypes into six clusters. Among the six clusters, cluster II was the largest with ten genotypes followed by cluster I with seven genotypes. The neighbour-joining tree developed based on weighted average for dissimilarity matrix grouped 30 genotypes into five groups. Among the five groups, group II comprised of ten genotypes followed by group I with eight genotypes. In both UPGMA analysis and neighbourhood joining tree, the results showed the potentiality of SSR markers in assessing the genetic diversity among the cowpea genotypes.

One hundred and eighty genotypes of cowpea (Vigna unguiculata (L.) Walp) were evaluated during kharif 2017 and thirteen biometrical traits were recorded. Analysis of variance revealed that significant difference existed among the genotypes for all the traits studied. The phenotypic coefficient of variation was higher than genotypic coefficient of variation for all the traits studied. The high estimates of GCV was found in traits viz., number of pods per plant, number of clusters per plant, hundred seed weight and single plant yield. High heritability was observed for plant height, days to 50 per cent of flowering, number of racemes per plant, peduncle length, number of pods per plant, number of clusters per plant, days to maturity, pod length, hundred seed weight and single plant yield. High heritability coupled with high genetic advance as per cent of mean was observed for plant height, number of racemes per plant, peduncle length, number of pods per plant, number of clusters per plant, pod length, hundred seed weight and single plant yield. The high degree of variability was observed among the genotypes for different yield contributing traits. This could be utilised in the breeding programme for the improvement of cowpea.