| The small brown planthopper, Laodelphax striatellus Fallen was an important pest on rice in Jiangsu, it transmitted rice stripe virus and caused rice stripe disease. The spread of rice stripe disease closely related to the numbers and transmission RSV capability of L. striatellus. The effects of rice varieties on the numbers, development and transmission RSV capability of L. striatellus from different geographical populations were studied in this paper. Results were as follows:1. In order to clarify the effects of rice variety on the numbers of L.striatellus, the number of L.striatellus on different japonica varieties was systematically investigated The results show that there was a inconsistant resistance of rice variety to the planthopper between Nilaparvata lugens and L.striatellus. The disease resistance of Ningjingl corresponded to the insect resistance of Huaidao9, but there was a great inconsistency on their resisitance of Nanjing44. The numbers of L.striatellus on Bing123resistance to N. lugens were significant larger than those on Zhejing22resistance to N. lugens. During tillering and jointing, the numbers of L.striatellus on resistant variety Huaidao9and Ningjingl were lower than those on Bing123. There was no significant difference in the numbers of L.striatellus on resistant variety between Nanjing44and Bing123.2. In order to clarify the relationship between rice variety and the numbers of L.striatellus, the effects of rice variety on the development and fecundity of L.striatellus among different geographical populations were systematically studied. By comparing resistance rice variety with susceptible one, Fuyang population reared on susceptible variety had shorter larval duration,higher sex ratio and fecundity of adult. Xuzhou population had longer larval duration, lower fecundity of adult, higher sex ratio of adult and higher eggs hatching rate. Yangzhou population had lower sex ratio and fecundity of adult and eggs hatching rate. Therefore, the variation of development parameters especially fecundity of adult among different geographical populations was affected by the rice variety.3. The transmission RSV capability of L. striatellus from different geographical populations reared on different rice variety were researched. The results indicated that the population reared on resistant rice variety had lower capability of carrying and acquiring virus, but the transmission virus capacity was not obviously changed. However, the transmission virus capability of L. striatellus reared on susceptible rice varieties had no change. The virus rate transmitted through eggs and acquired virus rate of the population from epidemic area (Yangzhou) reared on resistant varieties reduced significantly. At the same time, the population from non-epidemic area (Fuyang) reared on resistant varieties had only lower virus rate transmitted through eggs. |
