RESPONSE OF (Glycine max (L.) Merr.,) GENOTYPES AGAINST Spodoptera littoralis BASED ON AGRO-MORPHOLOGICAL AND MOLECULAR MARKERS

Abstract

Defoliating insects can cause significant damage to soybean plants in Egypt. The cotton leaf worm (Spodoptera littoralis) is a major pest of soybean and important economic insect pests in Egypt than other insect pests. Susceptibility of 15 soybean genotypes to infestation of cotton leaf worm Spodoptera littoralis were studied under natural field conditions. The relationship between agro-morphological and molecular DNA in relation to leaves defoliation were also studied. Defoliation of tested plants by the cotton leaf worm, in the field screenings system showed the genotypes L105 and L153 recorded the highest values of insect resistant and recorded defoliation ranking from zero to 0.1 respectively, followed by genotypes named H10L10A, L162, and H1L1. Whereas, AGS-129 genotype showed a maximum insect susceptible had defoliation score (4.0) indicating heavy insect feeding, over both seasons. Moreover, highest values of seed yield/fed recorded by L 153, H10L10A and H1L1, this attributed to the considerable increasing in number of branches/plant, 100-seed weight and number of pods/plant over both seasons, representing those genotypes are promising and could be suggested for release, also; these genotypes revealed to high insect resistance to cotton leaf worm. In total 13 SSR primers amplify 45 bands. The polymorphic SSRs were successfully used to distinguish cotton leaf worm resistance among soybean genotypes. In general, it could be supposed that the some soybean genotypes, H153, H105, L162 H1L1 and H10 L10 are promising genotypes that can be used in cultivation to expand soybean resistance to cotton leaf worm.