秦岭南坡短柄枹栎和锐齿槲栎的种子产量和种子大小及其与昆虫寄生的关系

【目的】为了解昆虫寄生特征与短柄枹栎 Quercus glandulifera 和锐齿槲栎 Quercus aliena var. acuteserrata 的种子产量及种子大小的关系。【方法】本研究于2011和2012年在秦岭南坡佛坪国家自然保护区，对短柄枹栎和锐齿槲栎种群的种子产量和昆虫寄生特征进行了野外调查研究。【结果】2年中短柄枹栎、锐齿槲栎种子雨密度和种子产量均差异明显，2011年短柄枹栎种子雨密度和种子产量分别为145.76±24.56粒/m²和74.97±11.56粒/m²，分别显著高于2012年的64.09±9.61粒/m²和34.30±3.51粒/m²；2011年锐齿槲栎种子雨密度和种子产量分别为238.88±43.97粒/m²和117.34±18.76粒/m²，分别显著高于2012年的112.00±19.20粒/m²和55.96±19.20粒/m²。2011年短柄枹栎和锐齿槲栎的种子产量中完好种子所占比例分别为49.73%和50.73%，分别显著高于2012年的38.69%和44.28%；而2011年虫蛀短柄枹栎和锐齿槲栎种子所占比例分别为28.05%和19.31%，分别低于2012年的39.77%和26.63%，但并无显著差异。2011和2012年，短柄枹栎和锐齿槲栎虫蛀种子个体均显著大于完好种子，且2011年二者虫蛀种子所含幼虫数与种子大小的相关性显著，2012年二者相关性不显著。【结论】短柄枹栎和锐齿槲栎种子的虫蛀率与种子产量有一定的关系，即在种子产量较低年份，虫蛀率有升高趋势，反之有降低趋势。同时，昆虫对这两种栎树种子中个体大的种子有寄生选择偏好，同时虫蛀种子所含幼虫数与种子大小也有一定的关系，即种子越大，所含昆虫幼虫数就越多。

Seed production and seed size and their relationship with insect infestation in Quercus glandulifera and Quercus aliena var. acuteserrata in the south slopes of the Qinling Mountains

【Aim】 This study aims to understand the relationship between insect infestation and seed production and seed size of Quercus glandulifera and Quercus aliena var. acuteserrata . 【Methods】 The seed production of Q. glandulifera and Q. aliena var. acuteserrata and insect infestation characteristics on their seeds in Foping National Natural Reserve, Qinling Mountains were investigated in 2011 and 2012. 【Results】 The seed rain density and seed production of Q. glandulifera and Q. aliena var. acuteserrata were obviously different between 2011 and 2012. The seed rain density and seed production of Q. glanduliferain 2011 were 145.76±24.56 nuts/m² and 74.97±11.56 nuts/m², respectively, which were significantly higher than those in 2012 (64.09±9.61 nuts/m² and 34.30±3.51 nuts/m², respectively). The seed rain density and seed production of Q. aliena var. acuteserrata in 2011 were 238.88±43.97 nuts/m² and 117.34±18.76 nuts/m², respectively, which were also significantly higher than those in 2012 (112.00±19.20 nuts/m² and 55.96±19.20 nuts/m², respectively). The proportions of intact seeds of Q. glandulifera and Q. aliena var. acuteserrata in 2011 were 49.73% and 50.73%, respectively, which were significantly higher than those in 2012 (38.69% and 44.28%, respectively). The proportions of insect-infested seeds of Q. glandulifera and Q. aliena var. acuteserrata in 2011 were 28.05% and 19.31%, respectively, which were lower than those in 2012 (39.77% and 26.63%, respectively), but the difference was not significant between 2011 and 2012. The seed size of the two insect-infested seed species was significantly larger than that of their intact seeds in 2011 and 2012. There were significant correlations between the number of insect larvae infesting seeds and seed size of Q. glandulifera and Q. aliena var. acuteserrata in 2011, but the correlations were not significant in 2012. 【Conclusion】 Our study demonstrated that there is a certain relationship between the insect infestation rate and the seed production of Q. glandulifera and Q. aliena var. acuteserrata in the lower seed production year, i.e., the insect infestation rate of seeds has a rising trend in the lower seed production year, and vice versa. Insects prefer to larger seeds of the two oaks for oviposition, and there is also a certain relationship between the number of insect larvae infesting seeds and the seed size, i.e., larger infested seeds contain more larvae.