天敌互作对乌桕生长及生物量的影响

Effects of Natural Enemy Interaction on the Growth and Biomass of Sapium sebiferum

通过比较地上广食性斜纹夜蛾、专食性癞皮夜蛾与南方根结线虫互作对乌桕生长及生物量的影响,分析不同空间天敌间的作用关系及植物的响应策略。结果表明:无南方根结线虫情况下,2种地上天敌显著降低了乌桕地径,且癞皮夜蛾处理组乌桕株高显著低于对照组;而有南方根结线虫情况下,地上天敌处理对乌桕地径、株高的影响无显著差异;南方根结线虫显著增加了癞皮夜蛾处理组乌桕地上生物量和总生物量。因此,南方根结线虫与癞皮夜蛾间形成了一种拮抗效应,从而对乌桕生长及生物量产生了加性效应,而这种效应在南方根结线虫与斜纹夜蛾间并不显著。

By comparing the interactions of the generalist Prodenia litura, the specialist Gadirtha inexacta and Meloidogyne incognita on the growth and biomass of Sapium sebiferum, the interaction patterns between different natural enemies and the response strategies of plants were analyzed. The results showed that in the absence of Meloi- dogyne incognita, the two kinds of above-ground natural enemies significantly reduced the diameter of Sapium seb- iferum, and the plant height with Gadirtha inexacta herbivory was significantly lower than the treatment without the presence of Meloidogune incognita. In the case of Meloidogune incognita, there was no significant difference in the effect of above-ground natural enemies on the diameter and plant height of Sapium sebiferum. Meloidogune incognita significantly increased the above-ground biomass and total biomass in the Gadirtha inexacta treatment group. There- fore, Meloidogune incognita and Gadirtha inexacta produced an antagonistic effect on each other, thus formed an additive effect on the growth and biomass of Sapium sebiferum. However, this pattern was not significant between Meloidogune incognita and Prodenia litura.