Characterization Of Vitellin And Effectation Of High Temperature On Its Vitellogenesis In Brown Plantthopper, Nilaparvata Lugens (St(?)l)

Brown plantthopper (Nilapavata lungens Stal. BPH) is a kind ol" important long-distance-transferring rice pest in Asia, which is also one of the main rice pests in the yangtse river valley and south and southwest in China, Temperature is one of the important factors that affect the dynamic of BPH. Most research about effect of temperature on development and reproduction of BPH focused on such respects as the dynamic change of population, its tolerance to high temperature et aJ. But there are few reports about the effect of high temperature on the development and reproduction of BPH when using high temperature to treat its different, instars of nymph.Part work was done to study the effect of high temperature on BPH. The main content includes: studying the effect of high temperature on the development and reproduction of BPH and the nymph period susceptive to high temperature; observation on the change of morphs of egg during the embryonic development with microphotograph; measuring the variation of quantity of vitellin (Vt) during the embryonic development with polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunity et al and measuring the variation of quantity of vitellin after using high temperature to treat different in star of BPH to research the effect of high temperature on vitellogenesis of BPH and the susceptible period,The result showed that the high temperature which is higher than 34℃ can suppress even stop the development of BPH nymph and the higher the temperature is, the more obvious the effect is. When the temperature reach to 38℃, it can even make the individual incapable of completing its development. The BPH has certain ability to endure high temperature, and the elder the instar is, the stronger the ability is.It is proved that the Vt. of BPH is a kind of protein containing sugar and fat using PAGE and different dying methods. The molecular mass of Vt. is 314 KDa, which consistsof three subunits with molecular mass of 148 KDa, 124.5 KDa, 44 KDa. Immunity experiment showed that the Vt. only exists in female adult of BPH. The Vt. of BPH is specific, and can not reactive with Vt. of White Back Plantthopper (WBPH).During the development of embryo, the conspicuous change of egg is that the eyespots came out and develops with time going. And almost all eggs can emerge 144hrs later after ovipositing. With the development of embryo, the Vt. is depleted gradually. In the first 48hrs, the quantity of Vt. almost has no change, but it become littler and littler after 48hrs. The Vt. still can be tested in 1st instar of nymph, but cannot in 2nd instar and the later instars.The Vt. quantity of female adult was tested after using high temperature to treat different instar of nymph, the result showed the vitellogenesis can be affected by high temperature weather in M-form female adults or B-form ones. And we also find that the Vt. Quantity change the mostly when using high temperature to treat the 4th instar of nymph. Contrasting with the contract, the Vt. quantity of B-form female adult has no obvious change at 1-day-age, but in nymph of other day-age, the Vt. Quantity become lower than the contrast. Before 5-day-age, the Vt. quantity of M-form is more than that of the B-form ones; but after 5-day-age, the Vt. quantity of the latter increase little by little and exceeds that of the former.