Conventional Breeding for Yellow Vein Mosaic Disease (YVMD) Resistance in Okra (Abelmoschus esculentus L. Moench); Progress, Challenges, and Opportunities

Abstract

Yellow Vein Mosaic Disease (YVMD), caused by begomovirus, represents the most detrimental threat to okra cultivation worldwide, significantly compromising yield, productivity and quality. As chemical interventions offer inadequate and often impractical control, the development of resistant or tolerant cultivars stands as the most practical long-term strategy. Substantial research efforts have identified potential resistance sources and elucidated the genetic basis of YVMD resistance. In India, public research institutions and private companies have employed various conventional breeding approaches including pure line selection, pedigree breeding, interspecific hybridization with backcrossing, and mutation breeding, to develop YVMD-resistant varieties. Effective utilization of okra genetic resources in resistance breeding programmes requires comprehensive knowledge of resistance sources in both cultivated and wild gene pools. This review synthesizes current knowledge on YVMD resistant sources across cultivated and wild okra germplasm, examines conventional breeding strategies for developing resistant cultivars, identifies major constraints encountered during breeding efforts, and proposes approaches to overcome these limitations. By consolidating the existing knowledge, and highlighting significant progress in conventional breeding, this article provides a strategic framework to guide future okra breeding programmes globally, focused on developing YVMD-resistant varieties with superior agronomic performance relevant to diverse ecological regions.