褐飞虱对抗性水稻品种Mudgo个体致害性指标

Individual virulence index of Nilaparvata lugens on a resistant variety of rice,Mudgo

在 2 8± 1℃下 ,观测了褐飞虱Nilaparvatalugens羽化 2 4h内短翅型雌成虫在敏感水稻品种TN1及抗性品种Mudgo上的寿命及体重增量。结果表明 ,取食抗性品种时 ,试虫的平均增重与寿命之间表现出明显的正相关。寿命在 7天内的个体 ,存活期间平均体重增量为负值 ,而存活 7天以上的个体则平均增重明显。进一步研究了初羽化的褐飞虱长翅型雌成虫在TN1及Mudgo上取食第 1～ 4天的体重增量、寿命及产卵量 ,结果发现试虫在Mudgo上的这 3个生物学参数之间存在明显正相关。其中 ,寿命及体重增量较好地反映出害虫个体对抗性品种的致害能力 ,可作为个体致害性指标。根据研究结果 ,提出将羽化后在Mudgo上存活 7天以上或最初 4天内体重增量大于 0 1mg的雌成虫定为能够致害该抗性品种的个体。

Longevity and weight gain of brachypterous females of Nilaparvata lugens that had emerged within 24 hours were investigated on two rice varieties,a susceptible variety TN1 and a resistant variety Mudgo, at 28±1℃. A positive correlation was detected between mean weight gain and longevity of females on Mudgo. Individuals that lived less than 7 days lost weight over their life-time, while those living more than 7 days significantly increased in weight.Furthermore, the longevity, fecundity and weight gain over 1-4 days of newly emerged macropterous females were studied on TN1 and Mudgo, and positive correlation was also found to exist between these three parameters in females on Mudgo. Among them longevity and weight gain better reflected the virulent capability of individual females, and thus could provide an index of individual virulence. Based on these results, it was proposed that newly emerged females on Mudgo that could survive over 7 days, or had a weight gain of more than 0.1?mg within the initial 4 days should be defined as virulent.