Progeny studies of interspecific crosses of Abelmoschus

Abstract

A study was conducted at the Department of Plant Breeding, College of Agriculture, Vellayani during 1987-’88 aimed at evaluating the F4 generation of interspecific hybrids between two yellow vein mosaic susceptible cultivars of Abelmoschus esculentus and the resistant semi-wild species, A. manihot for yellow vein mosaic resistance and yield. The estimation of genetic parameters of important economic characters, the association among these characters and the path coefficient analysis were undertaken. The F4 progeny lines were evaluated in an RBD with three replications. The genotypes showed significant differences in most of the characters studied. Genotypic coefficient of variation was maximum for number of branches per plant and minimum for first fruiting node. Plant height, days to flowering and fruiting phase showed high heritability and appreciable genetic advance while number of seeds per fruit recorded moderately high heritability and appreciable genetic advance indicating the presence of additive gene action. Number of branches per plant, fruit girth and yellow vein mosaic intensity exhibited high heritability and low genetic advance, while weight of single fruit, fruit length and shoot and fruit borer incidence recorded moderately high heritability and low genetic advance. Correlation studies revealed that number of branches per plant, number of fruits per plant, fruiting phase, number of flowers per plant, weight of single fruit, percentage fruit set, fruit length, fruit girth and number of seeds per fruit exhibited positive correlation to yield and could be considered as the major yield attributing characters. Path coefficient analysis projected number of fruits per plant and plant height as the traits exerting high positive direct effect on yield, while number of branches per plant, number of flowers per plant and fruit length exerted high positive indirect effect on yield through number of fruits per plant. The study indicated that the model for selection of a high yielding variety of bhindi should be based on number of fruits per plant, plant height, number of flowers per plant, fruit length and number of branches per plant. However, scoring for yellow vein mosaic intensity in the F4 progenies revealed that plants resembling the wild parent A.manihot in its short stature, lesser number of branches, increased fruit girth and number of seeds per fruit were resistant to the disease. However, since the fruits of these plants did not conform to the quality standards of cultivated bhindi and had higher percentage of shoot and fruit borer incidence, they were not selected. Plants resistant to the disease and resembling the cultivated bhindi were selected to carry forward to the next generation.