Studies On Resistant Traits In Okra To Leafhopper Amrasca Biguttula Biguttula Ishida

Abstract

Studies were conducted by screening 23 okra genotypes against leafhopper Amrasca newlinebiguttula biguttula Ishida to identify the source of resistance. The highest leafhopper population newlinewas recorded on AE 26 (28.79/plant) which was found to be highly susceptible to leafhopper newlinewith pooled mean damage index of 3.23. The moderately resistant okra genotypes (AE 65, AE newline23, No.315 and AE 4) recorded the minimum leafhopper population in the range of 2.28 to newline5.95/plant with damage index of 1.18, 1.30, 1.45 and 1.95, respectively. However, none of the newlinegenotypes was found to be completely resistant to leafhopper. newlineStudies on morphological, biochemical and anatomical traits showed that total trichome newlinedensity on leaves and trichome length were maximum on AE 65 (101.90 Nos/cm2 and 72.51, newline70.66, 84.07 and 69.42 and#956;m/cm2 leaf area) and had negative correlation with leafhopper newlinepopulation. With reference to biophysical parameters, plant height, leaf area, number of primary newlinebranches/plant and fruit length had positive correlation with leafhopper population while, single newlinefruit weight and fruit width had negative correlation with leafhopper population. Regarding newlinebiochemical parameters, total phenols, OD phenols and surface wax contents were negatively newlinecorrelated while total chlorophyll, total sugars, reducing sugars, non reducing sugars and protein newlinewere positively correlated with leafhopper population. Anatomical characters viz., leaf newlinetoughness (kgf/cm2), is eloquent that the highest leaf toughness was recorded in AE 65 (0.70 newlinekgf/cm2). newlineAmong the nutrients such as C, N, O, Na, Mg, Al, Si, P, S, Cu, K, Ca, Mn significant newlinenegative correlation existed with C, O, Si and Mn while positive correlation was recorded newlineamong other nutrients with leafhopper population. Results from ultra-microscopic studies newlineshowed that trichome density, trichome length, leaf lamina and midrib thickness were negatively newlinecorrelated with leafhopper population while trichome distance, trichome width and stomatal newlinedensity showed significant positive correlation with the populat