GENETIC DIVERSITY STUDIES FOR ASSESSMENT OF VARIABILITY IN OKRA (Abelmoschus esculentus (L.) Moench)

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Okra (Abelmoschus esculentus (L.) Moench) is an important crop in many countries due to its nutritional value, culinary uses, and economic significance. Genetic improvement of okra for yield is significant to overcome the low genetic potential of the existing varieties and environmental factors which are the major constraints to okra yield. This study was carried out to understand the genetic diversity of okra for effective selection of traits. Seeds of five varieties of Okra (Abelmoschus esculentus) were collected at the National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan, Oyo State, Nigeria. The seed of each accession was sown in a plot laid out in Randomized Complete Block Design with three replications. Data were collected on thirteen agronomic characters and analyzed. Phenotypic coefficient of variation varied for fresh pod length (9.44) to dry pod weight (29.13), whereas, genotypic coefficients of variation varied from dry pod width (3.18) to plant height (25.60), both indicated considerable diversity in the germplasm studied for various agronomic traits as a result of interaction between the genotypes and the environment. The PCV was moderately higher than GCV in all of the traits studied, which indicated that environment played a little role in the expression of these traits. The low heritability associated with low genetic advance for number of leaves (14.57%, 6.66%), number of branches (11.73%, 5.15%), number of fruits (7.95%, 2.43%), fresh pod length (27.27%, 5.33%), dry pod width (6.44%, 1.62%) and 100-seed weight (25.97%, 5.08%) revealed that environment or non-additive gene action may be prevailing for these characters and so heterosis breeding will be beneficial. High heritability and high genetic advance as percent of mean were recorded for plant height (79.80%, 47.11%), days to flowering (87.60%, 25.43%) and dry pod length (70.63%, 39.64%), indicating that these traits were less influenced by environment and presence of additive gene action. NGB02436 exhibited the highest dry pod weight, suggesting potential for higher seed yield per pod. NGB00425 had the highest 100-seed weight, indicating larger individual seeds which may impact seedling vigor and final yield. NGB02518, NGB00346 and NGB00401 had longer internode length, longer plant height and their productivity is comparatively low due to low number of fruits per plant. A wide range of variability and heritability with high genetic advance was observed for the characters like plant height, days to flowering and fresh pod length. Therefore, selection of superior genetic materials based on these performances could be very effective.