Multivariate Assessment of Genetic Variation and Trait Associations in Moth bean (Vigna aconitifolia Jacq.)

The standard methodology for assessing seed size distribution of pulses is to sieve seeds into size classes, weighing each class and calculating a weighted mean of the sieve sizes (seed size index). A single unit measure of uniformity of size within a sample via sieving is not available, despite being an important trait in terms of appearance, ease of milling, and consistency in processing. This study investigated several different models for estimating the size variability within seed samples by using a variety of desi and kabuli chickpea, faba bean, lupin, lentil, and mungbean samples. Fitting a normal distribution to the frequency distribution and using the estimated variance parameter as a measure for seed size variability was found to be the most suitable method for attaining seed size and a single value of uniformity. Mean seed size (SSnorm) and within‐sample size variability (SVnorm) were unrelated variables, thus allowing selection of more uniform samples of any desired size in breeding programs. Sieve selection is discussed and needs to be appropriate for the samples under investigation. Examples of using the R software to calculate these measures and the R functions needed are available as supplementary files to facilitate the use of this proposed method. This method will be useful to pulse breeders and researchers and in the development of image analysis methods characterizing seed sizes of pulse samples and other grains.

Seed weight and size are important yield components. Thus, selecting for large seeds has been a key objective in crop domestication and breeding. In common bean, seed shape is also important since it influences industrial processing and plays a vital role in determining the choices of consumers and farmers. In this study, we performed genome-wide association studies on a core collection of common bean accessions to dissect the genetic architecture and identify genomic regions associated with seed morphological traits related to weight, size, and shape. Phenotypic data were collected by high-throughput image-based approaches, and utilized to test associations with 10,362 single-nucleotide polymorphism markers using multilocus mixed models. We searched within genome-associated regions for candidate genes putatively involved in seed phenotypic variation. The collection exhibited high variability for the entire set of seed traits, and the Andean gene pool was found to produce larger, heavier seeds than the Mesoamerican gene pool. Strong pairwise correlations were verified for most seed traits. Genome-wide association studies identified marker–trait associations accounting for a considerable amount of phenotypic variation in length, width, projected area, perimeter, and circularity in 4 distinct genomic regions. Promising candidate genes were identified, e.g. those encoding an AT-hook motif nuclear-localized protein 8, type 2C protein phosphatases, and a protein Mei2-like 4 isoform, known to be associated with seed size and weight regulation. Moreover, the genes that were pinpointed are also good candidates for functional analysis to validate their influence on seed shape and size in common bean and other related crops.

Decision letter: Data-driven, participatory characterization of farmer varieties discloses teff breeding potential under current and future climates

Chilli (Capsicum annuum L.), an annual herb of the Solanaceae family (2n=24), originated in Tropical America and was introduced to India by the Portuguese in the 16th century. Among the 30 species of Capsicum, five are cultivated, with C. annuum being the most commercially important due to its high economic and nutritional value. Its fruits are rich in vitamins A, C and E, and bioactive compounds like capsaicin, capsanthin and oleoresin, which have culinary, industria, and medicinal applications. The present study evaluated genetic variability and trait associations in F4 population of chilli (Capsicum annuum L.) derived from the cross JNA1 × Byadgi dabbi. Conducted during the late Kharif season of 2024-25 at UAS, Raichur, the experiment involved 45 F4 lines and four check varieties in an Augmented Block Design. Eleven morphological and yield-related traits were recorded. Analysis of variance revealed significant genotypic differences for most traits, indicating the presence of substantial genetic variability. Descriptive statistics and high coefficients of variation for fruit diameter, test weight, fruit weight per plant and dry fruit yield per plant confirmed this variability. High genotypic and phenotypic coefficients of variation, heritability and genetic advance as percent of mean were observed for fruit length, chlorophyll content and leaf area, suggesting strong additive gene action. Correlation analysis showed that dry fruit yield per plant had strong, significant positive correlations with fruit weight per plant, number of fruits per plant, fruit length, test weight and plant height. These traits emerged as reliable indicators for yield improvement. In contrast, fruit diameter, number of primary branches and days to 50% flowering had weak or non-significant correlations with yield. The findings underscore the genetic potential within the F4 population. Traits with high heritability and strong yield associations should be prioritized for selection in chilli breeding programs.

Rice (Oryza sativa L.) is one of the world’s most important cereal crops, serving as a staple food and a key component of food and livelihood security across Asia. However, rice productivity has stagnated in several regions due to multiple biotic and abiotic stresses, variable climate and a narrow genetic base in modern cultivars. To sustain productivity and enhance yield potential, understanding genetic parameters and interrelationships among yield components is essential for effective selection and crop improvement. The present study was carried out at the Agricultural Research Station, Ragolu, Andhra Pradesh, during the Kharif 2024 season to assess the genetic variability, heritability and associations among yield-related traits in 22 advanced rice breeding lines in RCBD. Significant variability was observed among genotypes for all traits, indicating sufficient genetic diversity within the experimental material. The close relationship between genotypic and phenotypic variation suggested limited environmental influence on trait expression. High h2 (>60%) combined with high GAM (>20%) for major yield components revealed that additive gene action was predominant, implying that direct selection would be effective for improving these traits. Correlation analysis showed that grain yield was positively associated with several yield-contributing characters such as filled grains per panicle, plant height, test weight and ear bearing tillers, suggesting that simultaneous improvement in these traits could enhance yield. Path coefficient analysis further confirmed that filled grains per panicle, test weight and plant height exerted strong direct effects on yield (0.30-0.99), whereas unfilled grains had negative effects. The study revealed wide genetic divergence, highlighting FGP and TW as key traits for selection, offering valuable opportunities for selection and breeding of high-yielding, resilient rice cultivars suited to diverse environments.

The study entitled Correlation and Path Coefficient Analysis for Seed Yield and Yield related traits in pigeon pea [Cajanus cajan (L.) Millsp.] took place at the Research and Education farm, Botany Department, College of Agriculture, Dapoli, during the Kharif season of 2022 across 14 various traits of Pigeon pea. The present study “Correlation and Path Coefficient Analysis for Seed Yield and Yield related traits in pigeon pea” aimed to evaluate the association and contribution of various agronomic and yield-related traits toward seed yield per plant in Pigeon pea by employing genotypic and phenotypic correlation and path coefficient analysis. Significant variability was observed among genotypes for all traits studied. Correlation analysis revealed that traits such as number of pods per plant, test weight, harvest index, and seed yield per plot had a strong positive association with seed yield per plant at both genotypic and phenotypic levels. Path coefficient analysis at the phenotypic level indicated that seed yield per plot, harvest index, and test weight had substantial positive direct effects on seed yield per plant, suggesting their critical role in yield determination. At the genotypic level, test weight, days to 50% flowering, seed yield per plot, and harvest index exhibited high positive direct effects, while pod length and plant height exerted notable negative direct effects. The findings suggest that selecting genotypes with higher test weight, harvest index, and seed yield per plot can effectively enhance seed yield per plant. The integration of correlation and path analysis provides comprehensive insight for targeted selection in breeding programs.

Genetic variability and diversity studies were conducted for five lodging resistance traits and ten grain yield-related traits in 104 rice germplasm lines. The results revealed that PCV values were slightly higher than GCV values, indicating the influence of the environment on trait expression. Heritability coupled with high genetic advance was observed for plant height, number of panicles per plant, panicle weight, number of grains per panicle, test weight, and grain yield, which indicates predominant additive gene action. Correlation analysis revealed a significant correlation between lodging resistance traits such as culm diameter, culm thickness, section modulus, and bending moment, and yield-related traits, namely number of panicles, panicle weight, and grain yield. Path coefficient analysis showed that bending moment, panicle weight, and days to 50% flowering exhibited the highest direct effects on grain yield. Culm thickness and culm diameter recorded negative indirect effects on grain yield. According to Mahalanobis D², the genotypes were divided into six clusters. Cluster I had the highest number of rice genotypes (83), followed by Clusters II and III with ten and eight genotypes, respectively. Clusters IV, V, and VI were mono-genotypic. The inter-cluster distance between Clusters V and VI was the maximum. Cluster III also exhibited a higher intra-cluster distance. Further, Cluster IV recorded the highest values for most of the lodging and yield-related traits. Cluster V recorded the lowest mean for days to 50% flowering and days to maturity.

Bambara groundnut (Vigna subterranea [L.] Verdc) is a highly nutritious grain legume with a significant potential to develop various commercial food and feed products. It is a resilient crop able to grow under harsh climates and poor soil conditions. Bambara groundnut productivity in South Africa is low (0.62 t/ha) compared to the attainable yield of the crop reaching up to 3 t/ha. The low productivity is attributable to a lack of improved and high yielding cultivars that are locally bred and adapted in the country. Genetically diverse and locally adapted Bambara groundnut landrace varieties and exotic collections are present in South Africa for strategic breeding to improve yield and yield-related traits and nutritional quality. The objective of this study was to determine the magnitude of the genetic diversity and population structure of Bambara groundnut collections of South Africa using high throughput single nucleotide polymorphisms (SNP) markers. Ninety-three genotypes were assessed using genotyping with 2286 SNP markers and some unique complementary morpho-agronomic traits of the crop. The mean genetic diversity value was 0.32, revealing moderate genetic differences among the assessed genotypes. Cluster and structure analyses grouped the test genotypes into two distinct categories. Further, the analysis of molecular variance partitioned the total genetic variation into among genotypes (90%), within genotypes (8%) and among populations (2%). The results revealed two heterotic groups for hybridization and selection programs. The following unique genotypes were selected: ARC Bamb 37 (with spreading growth type), ARC Bamb 49 (bunch type), ARC Bamb 61 (semi-bunch) and ARC Bamb 83 (spreading) using the SNP markers and desirable agronomic traits. The study provided new insight on Bambara groundnut genetic profiles of South African collections which will assist in conservation strategy and management of the crop for effective breeding.

A digital image analysis method for assessment of lentil size traits

Preface Part I. Phylogenetic Perspectives: 1. Comparing plants and connecting traits J. Silvertown, and M. Dodd 2. Phylogenetic uncertainties and sensitivity analyses in comparative biology M. Donoghue, and D. Ackerly 3. Comparative ecology of the native and alien floras of the British Isles M. J. Crawley, P. H. Harvey, and A. Purvis Part II. Reproductive Traits: 4. The comparative biology of pollination and mating in flowering plants S. C. H. Barrett, L. D. Harder, and A. C. Worley 5. How does self-pollination evolve? Inferences from floral ecology and molecular genetic variation S. C. H. Barrett, L. D. Harder, and A. C. Worley 6. Effects of life history traits on genetic diversity in plant species J. L. Hamrick, and M. J. W. Godt Part III. Evolutionary Ecology of Seed Dormancy and Seed Size: 7. Evolutionary ecology of seed dormancy and seed size J. L. Hamrick, and M. J. W. Godt 8. Comparative ecology of seed size and dispersal M. Westoby, M. Leishman, and J. Lord 9. Packaging and provisioning on plant reproduction D. L. Venable Part IV. Recruitment and Growth: 10. Comparative ecology of clonal plants J. M. van Groenendael, L. Klimes, J. Klimesova, and R. J. J. Hendriks 11. Life history variation in plants: an exploration of the fast-slow continuum hypothesis M. Franco and J. Silvertown 12. Life history evolution in heterogenous environments: a review of theory R. M. Sibly Part V. Interaction: 13. Plant-insect feeding associations D. Futuyma, and C. Mitter 14. Trends in the evolution of root-microbe symbioses A. H. Fitter, and B. Moyersoen 15. Competitive ability: definitions, contingency and correlated traits D. Goldberg Index.

Presence of genetic diversity is a prerequisite for genetic improvement of any crop. As lodging and associated grain loss is a problem in kodo millet, a study was undertaken to characterize and assess the diversity in kodo millet germplasm accessions for culm strength and grain yield-related traits. Principal component and cluster analyses were performed for grouping the genotypes and to identify the traits that contributed significantly to the diversity in kodo millet. Cluster analysis grouped the genotypes into four main clusters. Cluster I had highest values for most of the traits, except internode length and grain yield. Cluster IV had smallest mean values for all studied traits. The genotypes in Cluster II had highest values for grain yield and test weight. Cluster III was intermediate in performance for most of the traits, hence genotypes in Cluster I could be used for improving culm-related traits and test weight, and those in Cluster II for improving grain yield and test weight and Cluster III for improving earliness.

Genetic variability and correlation studies provide basic information concerning the genetic properties of the population based on which, breeding methods could be formulated for further improvement of the crop. The estimates of heritability, coefficients of variability, genetic advance and trait association were computed for eleven yield related traits in F2: 3 segregating populations of biparental crosses under slightly sodic condition. Analysis of variance revealed significant differences for the traits studied except, effective tillers per plant, panicle length and test weight, indicating the existence of high genetic variability among the lines. Estimates of phenotypic coefficients of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the characters studied, indicating considerable effect of environment. Moderate heritability accompanied with high genetic advance was recorded for filled grains and unfilled grains per panicle which, indicates heritability is most likely due to additive gene effect and selection for the traits will be effective. Traits like: effective tillers per plant, panicle length, filled grains per panicle and total grains per panicle that showed, positive and significant association with grain yield per plant, could be useful for breeders in any breeding program for further improvement of the traits under sodic condition.

Mung bean (Vigna radiata L. Wilczek) is a nutritionally rich pulse crop valued for its protein content and soil fertility enhancing properties, yet its yield improvement remains constrained by complex genetic and environmental interactions. Although previous studies have examined variability or trait associations in mung bean, few have integrated multiple biometrical approaches to simultaneously quantify variability, correlations, path effects, and genetic diversity across a large set of genotypes. This study evaluated 60 genotypes sourced from NBPGR during Kharif 2024 in a randomized block design to quantify genetic variability, trait associations, and diversity for 11 agro-morphological traits. Substantial variation was observed, with seed yield per plant ranging from 3.29 g to 17.35 g and recording the highest coefficient of variation (12.50%). Days to 50% flowering exhibited the lowest variability, underscoring its stability across genotypes. Correlation analysis revealed strong positive associations of seed yield with pod yield per plant (r = 0.749**), test weight (r = 0.395**), and number of seeds per pod (r = 0.295**), while negative associations were noted with plant height and flowering time. Path analysis confirmed pod yield per plant as the most influential determinant of seed yield, exerting the highest direct effect (0.7653). Cluster analysis grouped genotypes into seven distinct clusters, with Cluster IV being the largest, and principal component analysis indicated that the first six components explained 81.5% of total variation. Collectively, these results highlight the potential of exploiting diverse and high-performing genotypes, particularly those combining early flowering with high pod yield, as parents in breeding programs aimed at yield improvement in mung bean.

Garlic (Allium sativum) has for centuries been valued by humans for food, culinary and medicinal purposes world over. The objective of this study was to investigate genetic variability among garlic accessions for yield, yield related and phenology traits in Ethiopia. A field study was conducted at the DebreZeit Agricultural Research Center during 2012, using 49 garlic accessions from the highlands of North Shewa, East and West Arsi, Arsi, Bale and Sidama zones, which are among the major garlic producing areas in Ethiopia. The experiment was arranged in a 7x7 simple Lattice design, with two replications. Accession were highly significant (P < 0.01) for days to maturity, leaf number per plant, neck diameter, yield per plant, biological yield per plant, dry weight above ground, bulb dry weight, dry weight underground, clove number per bulb, and clove weight per bulb. Heritability estimates ranged from 82.48% for clove number, to 6.46% harvest index. High heritability, combined with high genetic advance (as per cent of mean) observed for mean clove number, yield per plant, biological yield per plant and clove weight per plant showed that these characters were controlled by additive gene effects. Thus phenotypic selection for these characters would likely be effective in variety selection and development. Bulb yield per plant had positive and highly significant genotypic and phenotypic correlations, with all characters, except plant height and harvest index. Path analysis at phenotypic level revealed that biological yield and bulb dry weight contributed major positive direct effects to bulb yield per plant. These traits showed positive and highly significant genotypic correlations with bulb yield except harvest index

The exploration of genetically variable accessions is the key source of germplasm conservation and potential breeding material for the future. The more diverse group of cultivars provides an ample opportunity to breeders for releasing new and superior varieties, considering their quality traits for direct commercial utilization. In this study, we assessed the genetic diversity of Cicer arietinum 70 accessions from Pakistan and USA using morphological traits, seed protein and molecular markers. Based on four morphological traits, the average coefficient of variation was calculated as 56.8% with significant correlation among yield traits. The analysis revealed that the accessions 1898, 2819, 3022, 3037, 3040, 3043, 3054, 3059 and 3063 were best in performance with a total of 12% environmental error. The cluster analysis based on protein data revealed 50% genetic diversity among accessions. The clustering pattern did not show any grouping that could be attributed to either the geographic distribution or the field performance. For molecular characterization of germplasm 5 PCR based RAPD primers, OPA4, OPA9, OPG13, UBC181 and UBC733b used were found to be polymorphic with 37% genetic diversity among local and exotic accessions. Whereas, 3 SSR primers viz., CaSTMS2, Ca- STMS15 and CaSTMS21 scored the genetic variability up to 55% by cluster analysis through UPGMA percent disagreement. The primers, TA72 and TA130 were linked with yield related traits, indicated highest dissimilarity index value (0.69) and notable variation in the identified promising lines. The Morphometric, Biochemical and Molecular markers reported here, are helpful to assess the extent of genetic diversity among Chickpea accessions and can be used to identify the unreported cultivars with desirable quantitative traits for improving Chickpea yield in Pakistan. Based on the study, the accessions 3043 and 3054 have been recommended to the breeders for their future use in multiplication and screening against various diseases.