EVALUATION OF COWPEA F2 POPULATION FOR RESISTANCE TO FLOWER BUD THRIPS (MEGALUROTHRIPS SJOSTEDTI)

Abstract

A study to screen F2 populations obtained from IT10K-837-1 x Sanzi for resistance to M. sjostedti. A total of 351 F2 plants were screened under field conditions and each line rated visually for thrips damage score, flower abortion rate, number of pods per plant and number of thrips per flower. The study was conducted during the 2020 cropping seasons where F2 seeds were planted under field conditions. Thrips damage score, flower abortion rate, number of pods per plant, and number of thrips per bloom was all visually scored for each accession. The data from the field and laboratory were analyzed using GENSTAT edition 12 to determine if there were any major variations among the cowpea genotypes. The approximate correlations among all measured parameters, including damage scores at 45 DAP, 55 DAP, 65 DAP, using were established using Breeding View software and heritability values were also calculated. There was a strong and significant correlation between thrips population and damage rating during the planting season. Thrips resistance levels identified in most genotypes in this study are interesting compared to the resistant check Sanzisabinli and can be further exploited for future studies to develop resistant varieties to improve cowpea yields.