稻褐飞虱致害性变异的研究

Virulent Shift in Populations of Nilaparvata lugens (Homptera: Delphacidae)

研究了杭州褐飞虱田间种群在抗虫品种ＡＳＤ７上强迫饲养多代后致害性的变化。结果表明，不同致害性的群体，在ＡＳＤ７上饲养４代后，均可转变成能为害ＡＳＤ７的ＡＳＤ７种群。反之，在无抗性胁迫的感性品种ＴＮ１上连续饲养７代，ＡＳＤ７种群对ＡＳＤ７的致害性逐渐减弱，最终退化为ＴＮ１种群。这表明褐飞虱的致害性是可变异的，水稻品种抗、感虫特性是其转化的诱因。

The shift of virulence in ASD7 of rice brown planthopper from field and laboratory was studied. The resultsshowed that the field populations with different virulence, of which the virulence was determined by the amount of honeydewexcreted on ASD7, can shift to ASD7 population after rearing four generations on ASD7 respectively. On the contrary, thevirulence of ASD7 population became weak gradually during rearing on TN1. After seven generations rearing on TN1, ASD7population degenerated into TN1 population. It is suggested that virulence of rice brown planthopper was variable and thecharacter of variety resistant or susceptible to insect was the exterior factor of virulent shift.