Marker assisted backcrosiing for transferring fusarium wilt (fusarium oxysporum f. sp. tracheiphilum) resistance into yardlong bean (vigna unguiculata subsp. sesquipedalis (L.) verdcourt

Abstract

The present study on “Marker assisted backcrossing for transferring Fusarium wilt (Fusarium oxysporum f. sp. tracheiphilum) resistance into Yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt)” was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani and Integrated Farming System Research Station (IFSRS), Karamana, during the year 2019-2022, with an objective to introgress Fusarium wilt resistant gene into yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) through marker-assisted backcrossing. From the study, the Fusarium oxysporum causing Fusarium wilt in cowpea was isolated from the Vellayani region, identified through morphological and molecular characterization, and the ITS sequence of the isolate was deposited in the NCBI database. The study also identified the sand: maize as the best medium for mass multiplication of the pathogen and 10% inoculum was standardized as the optimum level for inoculation for artificial screening for Fusarium wilt resistance in cowpea. The cowpea variety IRON was identified as a probable donor for Fusarium wilt resistance, and a transferable SSR marker from the chickpea, UASBC59 was identified for use as Fusarium wilt-resistant linked SSR marker in cowpea. The 35 BC2F1 lines found resistant to Fusarium wilt as part of the study could be used as breeding lines for developing promising varieties with commercial traits of Githika and Fusarium wilt resistance of IRON