Selection And Identification Of Host Plant Resistance To Q Biotype Bemisia Tabaci From 550 Cotton Genotypes In The Field And Greenhouse Experiments

Whitefly Bemisia tabaci contains more than 35 cryptic species, Bemisia tabaci Q biotype as a typical phloem sap-sucking insect in China. It is a more serious trouble for cotton production all over the world. Plants have developed sophisticated systems to cope with herbivore challenges in nature. Morphological barriers in cotton such as surface hair and trichomes play important role in resistance to whitefly. Gossypol is a plants secondary metabolite helps to reduce crop damage in a large extent during pests attack. Five hundred fifty Gossypium genotypes were evaluated for whitefly adults’ population in two field experiment and three greenhouse experiments. Finally, 23 insect resistant and 19 insect susceptible genotypes were selected.The genotypes with glabrous leaf traits were found to be the resistant against whiteflies and genotypes with low gossypol content species traits were susceptible to whiteflies. Insect resistance index determination showed that leaf having lower density of hair was involved in resistance to eggs/nymphal, as well as short length of leaf hair played an important role in insect resistance. This study revealed that okra leaf traits reduced Bemisia tabaci Q biotype adult preference. Glabrous leaf hair traits helped in reduction of adults, and decrease oviposition preference. The glands underside cotton leaf were involved in plant-insect interactions, they produce some secondary metabolites that may help plants in defending them against pests, infections, and fungus, and aiding them to fight for survival and reproduction. Gossypol helped to reduce whitefly adults’ development and/or survival. These selected whitefly resistant germplasm and the cotton host resistant mechanism were important to cotton genetics and breeding.