Development of novel interspecific hybrid between cultivated and wild species of okra [Abelmoschus esculentus (L.)] Moench through embryo rescue

Abstract

A reproducible embryo rescue technique has been developed for producing YVMV resistant okra in which embryos developed through hand pollination between a cultivated okra species Abelmoschus esculentus (Cv. Pusa Sawani) and wild species, A. moschatus subsps tuberosus (IC 470750) were excised at a very specific stage and germinated on agar solidified medium containing a basic salt mixture and carbohydrate. The choice of carbohydrate and the growth conditions employed were demonstrated to markedly affect the germination percentage and subsequent plantlet development. This technique has been proved successful for the production of F1 hybrid when compared to conventional methods of hand pollination followed by post-zygotic development on plant itself, which generally leads to embryo abortion in case of interspecific hybridization between two sexually cross-incompatible species of okra. The trueness of interspecific hybrid plant obtained through embryo rescue technique from a cross between cultivated and wild species (tertiary to primary gene pool) of okra was confirmed by morphological and molecular characterizations. The two parents and F1 hybrid developed were characterized morphologically using DUS parameters set for okra. The optimization of this technique will overcome pre and post-fertilization barriers coming across in the interspecific hybridization process and will pave the way further for gene introgression through distant hybridization in okra.