Interspecific hybridization as a way of resistance transfer against viruses in okra: Hindrances and way forward

Abstract

AbstractOkra (Abelmoschus esculentus L. Moench) is considered as a treasure house of nutrients and it is one of the major vegetables widely spread all over tropical, subtropical and warm temperate regions of the world. Yellow vein mosaic virus (YVMV) and enation leaf curl virus are the most destructive diseases of okra as they affect both crop growth and yield. Due to the frequent breakdown of resistance and lack of a stable source of resistance in the cultivated species, interspecific hybridization is considered as a reliable approach for durable resistance. Cultivated species from The United States Department of Agriculture and wild accessions from The National Bureau of Plant Genetic Resources were screened at YVMV hotspot (Guntur, Andhra Pradesh) to identify the potential donors for disease resistance. Accessions IC141032 and IC141012 were found to be free from both viruses and categorized as resistant lines. Interspecific hybridization between A. tetraphyllus and A. esculentus revealed a high crossability index of around 80% when A. esculentus was utilized as a female parent. The bottleneck of hybrid sterility was partially overcome by the colchicine treatment of interspecific F1 hybrids. Good seed set was observed when raw colchiploids were backcrossed to the recurrent parent.