IN VITRO EMBRYO RESCUE OF INTERSPECIFIC CROSSES FOR TRANSFERRING VIRUS RESISTANCE IN OKRA (ABELMOSCHUS ESCULENTUS (L.) MOENCH)

Yellow vein mosaic (YVM) is the most serious white fly transmitting virus disease of okra (Abelmoschus esculentus L.) causing severe yield loss. As resistance is not available in cultivated species of okra, interspecific crosses were made between A. esculentus and A. moschatus (resistant wild species) to develop resistant varieties. Post zygotic incompatibility was found to operate between the species. Crossed seeds were shriveled and non viable. In vitro embryo rescue to overcome the incompatibility revealed that culturing 12 and 15 day old embryos of A. esculentus var. Kiran (a high yielding line) x A. moschatus and A. esculentus var. Anakomban (a landrace) x A. moschatus on MS medium supplemented with BA 0.5 mg L^-1 and CW 150 ml L^-1 yielded transplantable hybrids. Embryos of crosses A. moschatus x A. esculentus turned brown by the 11th day of pollination and could not be cultured In vitro. Multiple shoot production of embryo-derived plants was accomplished when cultured on MS medium supplemented with BA 1 mg L^-1 and CW 150 ml L^-1. Rooting of In vitro produced plants was achieved in MS medium supplemented with IAA 1 mg L^-1.