共生菌对褐飞虱生长发育和生殖的影响

对褐飞虱田间种群和生物型1在缺乏共生菌情况下取食不同抗性水稻品种后的生长发育和生殖的研究结果表明，取食抗性品种的褐飞虱体内共生菌数量均明显比取食感虫品种TN1的褐飞虱少，而取食抗性品种IR26、Mudgo和ASD7的2龄田间种群褐飞虱若虫的共生菌减少量均超过了50％。在感虫和抗虫水稻品种上，缺乏共生菌的褐飞虱若虫历期均显著长于正常若虫历期，若虫存活率、雌成虫体重、生长速率和产卵量均显著低于正常褐飞虱。正常的褐飞虱田间种群和生物型1在取食感虫和抗虫品种时的若虫历期均无显著差异，但缺乏共生菌的生物型1在取食抗虫品种Mudgo和ASD7时的若虫历期显著长于取食感虫品种TN1时的若虫历期。推测共生菌在褐飞虱适应水稻抗性品种的过程中发挥了重要作用。

THE EFFECT OF ENDOSYMBIOTE ON THE DEVELOPMENT AND REPRODUCTION OF BROWN PLANTHOPPER NILAPARVATA LUGENS STÅL

Under aposymbiotic state (by treated with high temperature), the number of symbiotes in brown planthopper (BPH) Nilaparvata lugens Stal fed on resistant rice varieties were significantly lower than that on susceptible rice variety TNI, and the symbiote amounts in 2nd instar nymph of field BPH population fed on resistant varieties IR26, Mudgo and ASD7 were more than 50% decreased, in comparison with that fed on TNI. Whether on susceptible or resistant varieties, the duration of nymphal stage of aposymbiotic BPH was markedly longer than that of normal BPH (not treated with high temperature) , and the survival of nymph and body weight, growth rate and fecundity of female adult of the former were all obviously lower than those of the latter. Contrarily, as the field population and biotype 1 of normal BPH fed on susceptible or resistant rice varieties, there were no significant differences among the durations of nymphal stage. Whilst in aposymbiotic biotype 1, as it fed on resistant Mudgo and ASD7, its nymphal durations were significantly longer than that on susceptible TNI. These facts suggested that the symbiote in BPH might play an important role in the adaptation process of BPH to the resistant rice varieties.