Biophysical and biochemical mechanism influencing shoot and fruit borer tolerance in brinjal genotypes

Abstract

Brinjal shoot and fruit borer, Leucinodes orbonalis, is an obnoxious pest causing fruit damage up to 92.50 per cent. The aim of this experiment was to ascertain the influence of biophysical and biochemical basis of tolerance to brinjal genotypes against L. orbonalis. An experiment was carried out during the summer season with fourteen selected brinjal genotypes at Bihar Agricultural University, Sabour (Bihar). Among the fourteen genotypes, six genotypes namely, RB-2 X BRBL-01, BRBL-02 x BRBL-07, 71-19 x RB-2, Arka anand, BRBR-01 X RB-2 and BRBL-07 x BRBL-02 were found tolerant against L. orbonalis and their per cent fruit infestation ranged from 25.84 to 29.27%. Six genotypes were susceptible and their infestation ranged from 37.55 to 39.79%. Two genotypes were highly susceptible and their infestation was ˃ 40%. The correlation study revealed that length of calyx had positive and significant correlation, whereas, trichome density and shoot thickness had negative and significant correlation with shoot and fruit borer infestation (number and weight basis). Total sugar and anthocyanin content (both shoot and fruit) had positive and significant correlation with fruit infestation, whereas, phenol and antioxidant content had significantly negative correlation with shoot and fruit infestation (number and weight basis). However, four genotypes, RB-2 X BRBL-01, BRBL-02 x BRBL-07, 71-19 x RB-2 and Arka anand were recorded with less shoot and fruit infestation, lower calyx length, more trichome density, low sugar content and high phenol content. These genotypes could be used as tolerant sources for shoot and fruit borer resistance breeding programme.