Deciphering biochemical traits for identifying the yellow vein mosaic disease resistance mechanism in okra

Abstract

Begomovirus-specific okra yellow vein mosaic virus disease (YVMVD) poses a significant loss to okra yield (~90 %). The potent approach to combat this yield loss is the development of resistant cultivars; however, the complex nature of the okra genome poses a challenge. The present study aimed to identify the biochemical basis of YVMVD resistance in okra. We investigated the biochemical alterations in okra introgression lines against YVMVD infection. The maximum disease incidence of 92.3 % was reported in the susceptible group at 45 DOI. Leaf samples collected at pre-flowering, flowering, and post-flowering stages were analysed for superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, hydrogen peroxide, proline, lipid peroxidation, and electrolyte leakage. Independent t-test and ANOVA revealed significant mean biochemical variability between resistant/susceptible groups and infected/healthy groups, indicating that the viral infection caused alterations in the biochemical contents. Except for lipid peroxidation and electrolyte leakage, the biochemical contents/activities peaked at the flowering stage with major manifestations in resistant genotypes, suggesting their positive relationship with YVMVD resistance in okra. The data obtained herein emphasize the importance of specific biochemicals as crucial markers for identifying the YVMVD-resistant okra varieties.