MORPHOLOGICAL CHARACTERIZATION AND QUALITATIVE TRAIT DIVERSITY IN COWPEA (Vigna Unguiculata L. Walp.) GENOTYPES UNDER SUMMER CONDITIONS IN SOUTH GUJARAT

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is an important warm-season multipurpose legume valued for its nutritional quality, adaptability, and contribution to sustainable agriculture. Morphological characterization of germplasm is essential for the identification of distinct genotypes, assessment of phenotypic diversity, and selection of suitable parental lines for crop improvement programmes. The present investigation was undertaken to characterize the morphological diversity of thirty vegetable cowpea genotypes using qualitative descriptors under summer conditions. The experiment was conducted during the summer of 2024 at the Vegetable Research Farm, Regional Horticultural Research Station (RHRS), ASPEE College of Horticulture, Navsari Agricultural University, Navsari, Gujarat. Thirty genotypes, including twenty-nine diverse accessions and one standard check (Pusa Phalguni), were evaluated in a Randomized Complete Block Design with three replications under three sowing dates. Ten qualitative morphological traits were recorded following the standardized IPGRI/IITA cowpea descriptor guidelines. Substantial phenotypic variation was observed for all qualitative descriptors, indicating the presence of a broad genetic base among the evaluated genotypes. Plant growth habit varied from erect (26.7%) and semi-erect (23.3%) to bush (20.0%), pole type (20.0%), and horizontal (10.0%). Kidney-shaped seeds were predominant (43.3%), followed by elliptical (33.3%) and rhomboid (23.3%) seeds. Considerable variation was also recorded for climbing tendency, plant pigmentation, terminal leaflet shape, leaf colour, leaf texture, flower colour, pod curvature, and mature pod colour. Flower colour was equally represented by white, yellow, and purple types, while curved pods and green mature pods were the most frequent phenotypes. The observed diversity demonstrates the distinct morphological identity of the evaluated germplasm and highlights the usefulness of qualitative descriptors for varietal characterization. The wide range of morphological variation observed among the cowpea genotypes provides valuable genetic resources for germplasm conservation and characterization. Genotypes possessing desirable traits such as erect growth habit, non-climbing tendency, kidney-shaped seeds, and straight green pods may serve as promising parental lines for vegetable cowpea improvement programmes aimed at developing high-yielding and agronomically superior cultivars