Effect of Cotton Leaf Morphological Characters on Incidence of Amrasca (Devastans Dist.) Biguttula Biguttula (Ishida)

Abstract

The aim of the study was to compare the effects of different gamma radiation doses e.g., 150, 200 and 250 Gy on leaf nectarines, leaf length, leaf width, trichome density and their length in relation to jassid population. The results showed highly susceptible, moderately susceptible and high resistance in parents and their gamma irradiated cotton lines against jassid populations during, 2008 and 2009. There was leafing length had non-significant and negative correlation with jassid populations in parents, 200 and 250 Gy, while, the leaf width and the leaf nectarines spots in parents and 150 Gy cotton lines. However, leaf length were non-significant and positive correlations in 150 Gy, whereas, the leaf width and the leaf nectarines spots in parents, 200 and 250 Gy lines during both years study. Trichome density and their length had negative and non-significant correlation with jassid populations in all parents and their gamma irradiated lines. Further liner regression coefficients results indicated that decrease in jassid population with leaf length, trichome density and their length; however, the population increased by leaf width on all parents and their gamma irradiated cotton lines during both year study periods. It is concluded that, plant leaf characters, i.e., leaf length, trichomes density and trichomes size are essential features to minimize jassid populations in cotton crop. The cotton seed irradiated at gamma doses 200 and 250 Gy were the most advantageous to develop resistance potential in cotton crops.