Gene exchange and dissection of genetic character associations among Okra

Abstract

Gene exchange and hybridization of okra [Abelmoschus esculentus (L.) Moench] are important for the development and utilization of new varieties. To study the existing diversity in attributes of okra germplasm and their potential for successful hybridization. The modes of inheritance of leaf shape, stem color, stem pubescence, leaf pubescence, petiole color, leaf color, fruit color, and fruit pubescence were studied to evaluate the possibility of gene exchange among okra varieties. Five okra varieties were characterized using morphological descriptors and parent plants were hybridized in all combinations. The parents, the F1 and F2 plants grown in the field were evaluated for growth and yield-related factors. The qualitative descriptors leaf shape and pubescence, presence, or absence of, anthocyanin in the leaf and stem, and chlorophyll intensity in leaves which are distinct contrasting characters were used for the mode of inheritance. Data collected based on the descriptors were analyzed for variance among parents and hybrid progeny. A chi-squared test was performed to determine the goodness of fit to the expected ratios in the F2 generation. There is significant variation (p<0.05) between parents and their crosses for vegetative growth and yield. All hybrids are elite as they started fruiting early. Most of the crosses performed better than their parents for growth and fruit-related characters. All qualitative characters in the F2 generation were monogenically controlled. Patterns of segregation in the F2 generation was statistically consistent with ratios of 3:1, 1:1 and 1:2:1, indicating that they are controlled by a single gene with complete (3:1 phenotypic ratio) and incomplete (1:2:1 phenotypic ratio) dominance. The gene exchange and mode of inheritance of characters among segregating generations provide information on which selection can be made to improve okra.