Assessment of anthracnose resistance and agromorphological traits in fifth-generation lima bean populations

Selection of lima bean (Phaseolus lunatus L.) genotypes based on morpho-agronomic descriptors in univariate and multivariate analyses

Abstract Lima bean (Phaseolus lunatus L.) is a legume of great agricultural, nutritional, and socioeconomic importance in tropical and subtropical regions. Although it shows high adaptation and elevated protein content, its productive and genetic potential remains underexplored due to the lack of regional studies and limited information on genetic variability. Thus, the characterization and evaluation of genetic variability are essential to support conservation and the selection of superior materials. This study aimed to morpho-agronomically characterize lima bean genotypes and analyze genetic variability using univariate and multivariate techniques to identify promising genotypes. Ten landraces of P. lunatus were cultivated of the Paraíba. The evaluated descriptors followed the recommendations of the International Plant Genetic Resources Institute and included qualitative traits seed [background color, primary color, and secondary color] and quantitative traits [number of seeds per pod, leaflet length and width, plant height, pod width, and pod length]. Data were subjected to descriptive analysis, ANOVA with Tukey’s test (1%), and estimates of genetic parameters. Selection was performed using Tocher’s clustering method and three selection indices: Williams, Mulamba & Mock, and the genotype–ideotype distance index (IDGI). Significant effects were observed for all variables at 1% and 5% probability levels, except for leaflet width, indicating high genetic variability. Heritability estimates were high, particularly for leaflet length (89.68%). Genetic variability was observed among the materials, and Branca Pequena, Cara Larga, Roxinha, and Moita stood out due to their superior performance across key agronomic traits, being recommended for selection and use in breeding programs.

Morphometric and Agronomic Characterization of Tepary Bean (Phaseolus acutifolius A. Gray) Landraces and Identification of High-yielding Accessions Introduced in Burkina Faso

Rainfed legume production in Burkina Faso is increasingly challenged by climatic variability. Diversifying grain-legume genetic resources may help address these constraints and support food security. Tepary bean (Phaseolus acutifolius A. Gray), a legume native to the south-western United States and northern Mexico, is tolerant of water stress, heat, and diseases. This crop may therefore provide an alternative for maintaining grain-legume production under erratic rainfall. This study evaluated the morphometric and agronomic characteristics of 36 tepary bean accessions introduced into Burkina Faso. The experiment was conducted over two consecutive years (2022 and 2023) at the Kamboinse research station using an alpha-lattice design with three replications. Fourteen quantitative traits were recorded using descriptors established by the International Board for Plant Genetic Resources. The results revealed morphometric and agronomic variability within the collection. Significant differences were observed among accessions and years, as well as for the accession × year interaction for selected traits. A strong positive correlation was observed between seed length and seed width. Plant height was the principal discriminating morphometric trait, whereas 100-seed weight and seed yield were the principal discriminating agronomic traits. Cluster analysis structured the accessions into three groups: Group II contained 16 accessions, Group I contained 12, and Group III contained eight. Accessions G40279 and G40173C from Group II showed high grain-yield potential and may be useful in breeding programmes targeting variable climatic conditions in Burkina Faso.

Phenotypic diversity of Moroccan cowpea landraces: insights for crop conservation and food security

Cowpea (Vigna unguiculata L. Walp.) is a multifunctional species originating from Africa, where it plays a key role in food security and sustainable agriculture. In Morocco, it remains a marginal crop that has been scientifically overlooked, despite its crucial role in food security, which limits its integration into genetic improvement programs and compromises the sustainable conservation and valorisation of this plant genetic heritage. A field experiment was conducted during the 2023 cropping season using a randomized complete block design with three replications to evaluate the agro-morphological diversity of 19 cowpea landraces collected from different regions of Morocco. A total of 50 qualitative and quantitative traits (morphological, phenological, and agronomic) were assessed at different growth stages. The results revealed a considerable level of variation across most assessed traits, supported by a high total phenotypic diversity (HT = 0.53) and a mean within-population diversity (Hs̄ = 0.45±0.20) that exceeded the among-population phenotypic diversity (GST = 0.16). The average phenotypic diversity (Hp̄) across landraces was 0.45, with no significant differences among landraces. principal component analysis (PCA) revealed significant variation among the 19 cowpea landraces, enabling their grouping based on similarities independently of their geographical origin, with landraces BH3, CF2, HG and TK1 being distinguished by a combination of desirable traits. These results show a considerable level of intra- and inter-landrace diversity among Moroccan cowpea landraces, providing essential information for their conservation, sustainable use, and incorporation into breeding and selection programs, which is particularly relevant as a strategic crop in the current context of climate change.

Exploring the phenotypic diversity of clove bean (Ipomoea muricata (L.) Jacq.) landraces for DUS-based morphological traits through multivariate analysis

Clove bean (Ipomoea muricata (L.) Jacq.) is an underutilised vegetable crop with significant potential for strengthening sustainable agriculture and global nutritional security. The conservation and utilisation of clove bean landraces are essential for breeding advancement and global nutritional security, owing to the limited availability and characterisation of germplasm resources. The present study evaluated fifteen clove bean landraces using 26 morpho-physiological, inflorescence, pod and seed descriptors to assess the extent of genetic diversity. Significant variability was observed across all studied traits, indicating the presence of substantial morphological divergence among the landraces. Correlation analysis revealed strong positive associations among plant type, canopy cover, vine internode length, mature leaf size and pigmentation traits, suggesting coordinated genetic control and the possibility of simultaneous improvement through selection. Floral characteristics, including flower length, flower width, sepal shape and sepal apex, exhibited highly significant positive correlations. Cluster analysis grouped the landraces into four distinct clusters, reflecting varying levels of divergence and identifying unique landraces such as Im-1 and Im-11. Principal component analysis indicated that the first six principal components had eigenvalues greater than one and together explained 88.95 % of the total variation, with PC1 contributing 39.86 %. Floral dimensional traits and vegetative vigour were the primary contributors to divergence. The identified landraces provide valuable genetic resources for future breeding, conservation and crop improvement programmes in clove bean.

Phenotypic diversity and selection of promising accessions of Cucurbita spp. from Peruvian germplasm

Genetic evaluation and selection of F₄ brinjal (Solanum melongena L.) segregants derived from Odisha landraces for yield, quality and tolerance to bacterial wilt

A field experiment was conducted at the All India Coordinated Research Project (AICRP) on Vegetable Crops, Odisha University of Agriculture and Technology (OUAT), Bhubaneswar, Odisha, India, during the rabi season, 2023-2024, with broad objectives of developing superior, green round-fruited brinjal genotypes for higher fruit yield, fruit quality and tolerance to bacterial wilt from local landraces. Additional objectives included genetic analysis, including studies of genetic variability, character association and path analysis, along with genetic divergence analysis for future population improvement of brinjal using local landraces. A total of 41 genotypes of brinjal, including 9 local landraces of Odisha as parents, 31 F4 segregants and one check (BB-67), were evaluated by using randomised block design (RBD) with 2 replications. The analysis of variance revealed significant differences among all traits, suggesting enormous scope for effective phenotypic selection in brinjal. The genetic variability study revealed a high broad-sense heritability (> 60 %) coupled with high genetic advance as % of the mean (> 20 %) for most of the traits except plant height (cm), days to 1st flowering and days to 50 % flowering respectively, hence suitable for phenotypic selection. Similarly, study on character association revealed that total fruit yield per plant in brinjal was significantly and positively associated with average fruit weight and number of fruits per plant at both genotypic and phenotypic level whereas the path analysis showed direct positive effects on total fruit yield per plant with traits viz., number of fruits per plant, average fruit weight, plant height at final harvest, days required to 50 % flowering, fruit length, fruit breadth, plant spread (NS) and fruit length breadth ratio, indicating that the direct selection for these traits would be effective in brinjal improvement. Principal Component Analysis (PCA) revealed 3 principal components with eigenvalues greater than unity (1.0), accounting for 78.647 % of the total variance.  Principal Component 1 (PC1) contributed the highest proportion of total variance (42.282 %) with an eigenvalue of 4.228. PC2 and PC3 explained 24.045 % and 12.32 % of the variance with the eigenvalues of 2.404 and 1.232 respectively.