Biophysical and biochemical bases of resistance to Maruca vitrata L. in selected vegetable cowpea genotypes

Host plant resistance is a crucial factor in mitigating the damages caused by Maruca vitrata, the most devastating pest of vegetable cowpea, commonly known as the legume pod borer. Understanding the biophysical and biochemical aspects of resistance is essential for developing methods to breed insect pest resistance in germplasm. To identify genotypes with diverse traits associated with resistance to this pest, we investigated the biophysical and biochemical traits implicated in conferring resistance to M. vitrata across ten accessions of vegetable cowpea, alongside resistant and susceptible check. Trichomes on pods emerged as a pivotal aspects of resistance in these genotypes, exhibiting a significant negative correlation with the percentage of seed damage inflicted by M. vitrata. In our study, genotypes with higher pod trichome density showed a reduction in seed damage caused by the pest. Additionally, a high phenol concentration and low levels of total sugars and proteins were associated with resistance to M. vitrata. Vegetable cowpea genotypes characterized by abundant pod trichomes and elevated phenol level hold promise for breeding efforts aimed at developing cultivars resistant to M. vitrata.