Searching for resistance in wild Lens species against pulse beetle, Callosobruchus chinensis (L.)

Abstract

A total of 51 accessions of different Lens spp. viz., Lens culinaris (cultivated) and L. culinaris subsp. odemensis, L. culinaris subsp. orientalis, L. orientalis, L. nigricans, L. lamottei and L. ervoides (wild species) were screened for their reaction to Callosobruchus chinensis under no-choice artificial infestation conditions to find the sources of resistance. Significant differences among the accessions in terms of number of eggs laid, development period, adult emergence, number of emergence holes of C. chinensis loss in seed weight on different Lens spp. were observed. Of the seven species tested, L. culinaris was the most preferred one for egg laying while L. ervoides was the least preferred. Based on Growth Index (GI), accessions were categorised as highly resistant (15 accessions, GI = 0.00), resistant (14, GI=0.00 to 1.00), moderately resistant (16, GI=1.01 to 2.00) moderately susceptible (3, GI 2.01 to 3.00) susceptible (3, >3.01) to C. chinensis and the species have been arranged in the order of their resistance to C. chinensis. viz L. ervoides > L. lamottei > L. nigricans= L. orientalis > L. culinaris subsp. orientalis= L. culinaris subsp. odemensis > L. culnaris, i.e. L. ervoides was highly resistant and L. culnaris was the most susceptible. Correlation between GI and growth parameters of pulse beetle on different Lens spp. accessions indicated that GI had negative relationship with mean development period (-0.22) and significant positive relationship with adult emergence (+0.73), weight loss (+0.77) and eggs laid (+0.75).