1Department of Biotechnology, College of Basic Sciences and Humanities, GKVK Campus, Bangalore 560 065, India
2Department of Agricultural Entomology, College of Agriculture, University of Agricultural Sciences, GKVK Campus, Bangalore 560 065, India
* Corresponding author.
Six cowpea genotypes namely TVX-7, V-154, DPLC-216, C-152, GC 82-7 and C-190 were selected for the study of the biochemical basis for insect-pest resistance. The total tannin, phenolic and protein contents for these genotypes were in the range 0.11–0.95, 0.01–0.05 and 17.41–19.60 per cent of defatted meal, respectively. The highest trypsin inhibitor and chymotrypsin inhibitor activities were found in GC 82-7, whereas highest protease inhibitor and α-amylase inhibitor activities were observed in TVX-7. α-amylase inhibitor activity was however, absent in V-154 and DPLC-216. Zymogram pattern for trypsin inhibitor activity showed considerable variations among the genotypes. The SDS-PAGE pattern indicated the major variations in the protein bands of molecular weights above 24 kD in all the six cowpea varieties.
cowpea, insect resistance, proteinase inhibitor
