褐稻虱生物型的形成

STUDIES ON THE FORMATION OF BIOTYDE OF THE BROWN PLANTHOPPER (BPH), NILAPARVATA LUGENS

本文研究褐稻虱连续饲养于具Bph1抗虫基因的IR_(2?)稻种上表现不同致害力群体与生物型形成的关系.试验结果表明,实验室群体的个体间存有不同的致害力.用蜜露分泌量区分不同“致害力”的群体在连续选择压力下,它们间适应IR_(2?)的程度并无明显的差异.三个不同“致害力”的群体应用“苗期群体筛选法”和“群体建立法”测定,表明在IR_(2?)上饲养经过10代,即可使IR_(2?)致死并能适应于该品种;但它们却不能生存于具有BpH_1抗虫基因的Mudgo稻种上.此外,根据蜜露分泌量、飞虱生存率和成虫体重等指标在连续饲养世代的递增,亦证实飞虱群体在IR_(2?)上经过不断的选择,可以演变为一个致害力强的生物型.

The present study was designed to obtain detail information on the relationship between the populations of different virulence and biotype formation oX BPH led on IR26 variety with Bphl resistant gene. It seemed that a distinct difference of individual virulence existed in the laboratory population,especially in resistant varieties IR26 and ASD7. The results showed that the different populations, of which the virulence was determined by the amount of honeydew excreted on IR26, had no significant difference in the degree of their adaptation to TR26 under the selection pressure. Using the seedling bulk test and the population build-up experiment, the 3 selected insect populations reared on IR26 in 10th generation were able to kill IR26 and adapted to these host plants but could't survive well on Mudgo variety with Bphl gene. In addition, the amount of honeydew excretion, survival and adult weight on IR26 increased during the selection process, the shift in the insect populations to a more virulent biotype was also confirmed by these tests.