Genetic Analysis Of Resistance To Brown Planthopper And Whitebacked Planthopper In The Restorer Lines Of Indica Rice

The brown planthopper, Nilaparvata lugens (Stol.) and whitebacked planthopper, Sogatella furcifera, each of them is one of the most serious insect pests of rice (Oryza saliva L.) throughout Asia, has posed a severe threat to rice production in Asia. One of the most safe, economical and efficient strategies to control rice planthopper is application of varietal resistance. The genetic analysis between the resistance to brown planthopper and the resistance to whitebacked planthopper were carried out using 3 restorer lines of indica rice, 2 male sterility lines and their progenies, which provides a theoretical guidance for practice of planthopper-resistance breeding program. On the same time, some physiological changes of rice plants infested by the brown planthopper and whitebacked planthopper were analyzed respectively, which was carried out using superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) as indicators. It was a primary attempt to direct insect-resistance breeding using plant physiology. The main results are summarized as below:1. Based on the resistance test to brown planthopper and whitebacked planthopper, the inheritance of resistance to brown planthopper and whitebacked planthopper were analyzed using 3 anther cultural restorer lines of indica rice (TE358, TE363, TE367), two male sterility lines ( II32A, XieqingzaoA) and their hybrid combination F1, F2, BC1F1 generations. All of three restorer lines of indica rice were found to have a single dominant gene for resistance to whitegbacked planthopper and a single recessive gene for resistance to brown planthopper. which segregate independently of each other. The results provide a good germplasms and theoretical guidance for the practice of both the planthoppers-resistance breeding program.2. The weight of honeydew excreted by BPH and WBPH were measured. After infestation, the activity changes of important enzyme in active oxygen elimination system were mostly studied. The results showed that BPH excreted more honeydew than WBPH feeding on the same rice plant, which implies that BPH does grate harm on rice than WBPH does. There are significant difference between the weight of honeydew excreted by BPH on TN1 and on resistant rice varieties, it is considerable to regard the weight of honeydew exceretd by BPH as an indicator of resistance degree to BPH. After rice plants were infested by WBPH, activity of superoxide dismutase (SOD) and peroxidase (POD) increased and ofcatalase (CAT) decreased in resistant rice varieties, but activity of POD and CAT decreased, SOD increased in susceptible rice varieties. After rice plants were infested by BPH, activity of SOD and CAT went up, POD went down in resistant rice varieties, but activity of SOD and POD increased, CAT decreased in susceptible rice varieties. The increase in activity of SOD caused by BPH infestation was greater than that of WBPH in resistant rice varieties, the reduction in activity of CAT caused by BPH infestation was greater than that of WBPH in susceptible rice varieties.