稻纵卷叶螟(Cnaphalocrocis medinalis(Gene))在水稻品种上的半自然种群生命表参数及对植株含糖量的影响

Life-table parameters of a semi-natural population of Cnaphalocrocis medinalis(güenée) on different rice varieties and changes in sugar content in rice plants after insect infestation

在排除天敌情况下,用生命表方法比较了稻纵卷叶螟在5个常用栽培水稻品种扬粳9538、淮稻9号、扬辐粳8号、扬稻6号和汕优63上的半自然种群生命表。结果表明,取食淮稻9号的稻纵卷叶螟种群趋势指数最低,表现为较强的抗耐性;扬辐粳8号的稻纵卷叶螟种群趋势指数最高;各品种间稻纵卷叶螟不同虫期的存活率、♀/♂、蛹重、产卵量、卷叶率有一定差异;稻纵卷叶螟为害后,植株内可溶性糖含量品种间无明显差异,但不同品种与对照(未接虫)相比含量有增有减;还原糖含量品种间差异显著。

In recent years, rice leaffolder, Cnaphalocrocis medinalis（Güenée） outbreaks in China have resulted in serious damage to rice. However, causes of these outbreaks have not been understood. Thus, life-table parameters of C. medinalis on five extended rice varieties, Yangjing 9538, Huaidao 9, Yangfujing 8, Yangdao 6, and Shanyou 63, were compared under a semi-natural population,i, e. , potted rice plants covered with a big cage （ 1.5 m length × 1 m width ×1 m height） and exclusion of natural enemies. These parameters were survival rate, fecundity, and index of population trend （ Ⅰ ）. Experimental results showed that the index of population trend of C. medinalis that fed on Huaidao 9 was the lowest among the five varieties, indicating that Huaidao 9 was resistant to the insect. That on Yangfujing 8 was the highest. The Ⅰ value for Yangfujing 8 was 3.56 times higher than that for Huaidao 9. The survival rate of different developmental stages, ratio of female adults to male adults （ ♀ / ♂ ） , pupa weight, number of eggs laid by female adults, and percentage damage of rice leaves varied with rice varieties. In addition, this study measured changes in biochemical substances in rice plants after pest infestation. The result demonstrated that soluble sugar content in plants on which C. medinalis larvae fed was not significantly different for different varieties, but was significantly different compared to control （non-feeding） plants. The reduced sugar content in plants was significantly different among the five varieties.