Influence of physical and biochemical constituents on resistance/susceptibility in sesame genotypes against leaf webber and capsule borer, Antigastra catalaunalis Duponchel

Field screening studies against leaf webber and capsule borer, Antigastra catalaunalis, were carried out
with sixty sesame genotypes along with a resistant check, SI- 250, and susceptible check, TC 25. The results
revealed that, seven sesame genotypes, viz., JCS 3894, JCS 3594, JCS 3593, JCS 3265, SI 9050, JCS 3910, and
JCS 3605, were categorized as resistant based on grading, and 22 genotypes were moderately resistant; thirty-
one sesame genotypes were categorized as susceptible. Among different categories of genotypes, physical
parameters and biochemical constituents were assessed in selected genotypes. Physical parameters, trichome
density, showed a significantly negative correlation (-0.932) with per cent leaf damage, and capsule wall
thickness showed a significant negative correlation (-0.898) with per cent capsule damage caused by
A. catalaunalis. Biochemical constituents viz., chlorophyll (0.748), total sugars (0.745) showed significant
positive correlation, and phenols (-0.888) showed significant negative correlation with per cent leaf damage.
Regarding, chlorophyll (0.797), total sugars (0.886), and reducing sugars (0.814) showed significant positive
correlation, and phenols (-0.878) showed significant negative correlation with A. catalaunalis capsule damage.
The multiple step-down regression studies showed that, physical and biochemical factors together influenced the
leaf and capsule damage to an extent of 94 and 99 per cent, respectively.