昆虫寄生与滇合欢种子大小和数量的关系

Insect infestation and its relationship with seed size and number of Albizia simeonis

以云南地区含羞草科合欢属滇合欢Albizia simeonis为研究对象,在调查滇合欢正常种荚和被昆虫寄生种荚内种子数、种子败育数和种子大小的基础上,研究昆虫寄生对滇合欢种荚内种子数量、大小以及败育的影响,分析了种荚内种子大小和数量之间的关系。结果表明:完好种荚与受害种荚内种子总数差异并不显著,但完好种荚内正常种子数量显著高于受害种荚,而败育种子数则显著低于受害种荚。昆虫寄生并没有对滇合欢种荚内正常种子大小产生显著影响,但被寄生的种子体积显著大于正常种子。种荚内败育种子数与被寄生种子数呈显著正相关关系,表明昆虫寄生对滇合欢种荚内种子败育产生了影响。滇合欢种荚内种子数量与种子大小呈负相关关系,但完好种荚内种子数量与大小的相关性并不显著,而有昆虫寄生的种荚内种子数量与种子大小则表现出显著的负相关,即昆虫寄生加剧了滇合欢种荚内种子大小与数量的权衡。

In order to understand the effects of insect infestation on seed size and number,the size and number of total seed,aborted seed and insect-infested seed in sound and infested fruit pods of Albizia simeonis were investigated,and the effects of insect infestation on seed abortion and the relationship between seed size and number were analyzed. The results showed that there is no significant difference of total number of seeds between in the sound and infested fruit pods. The number of sound seeds in sound fruit pods was higher than that in infested fruit pods,but the number of aborted seeds was lower than that in infested fruit pods. There is no significant effect of insect infestation on the size of the sound seed,but the volume of infested seed was larger than that of sound seed. The observed significant positive correlation between the number of aborted and infested seeds in fruit pods indicates the effect of insect infestation on seed abortion. The negative correlations between seed volume and number were found both in sound and infested fruit pods,while this correlation was not significant in sound fruit pods but significant in infested fruit pods. The results suggest that insect infestation enhanced the trade-off between size and number of seed in fruit pods of A. simeonis,this trade-off can be a response of A. simeonis to insect infestation,which may improve the adaptability of this plant.