重庆市松墨天牛的形态变异与环境因素的关系

Morphological Variations and Their Relationships with Environmental Factors of Monochamusalternatusin Chongqing

【目的】考察重庆市不同地理种群松墨天牛(Monochamus alternatus)的形态变异与环境因素的关系。【方法】对采自重庆市12个区县的107头松墨天牛的体长、体宽、前胸背板长、前胸背板宽、前胸背板斑纹等形态学特征进行了观察和测量,根据标本采集地的地理位置和气候要素数据将重庆市松墨天牛分为6个自然地理种群,考察了上述形态特征在种群内和种群间的变异及相关性,并分析了形态变异与环境因素间的相关性。【结果】松墨天牛个体在种群内和种群间的变异系数均较低,西北种群形态与其他5个种群形态差异较大,6个地理种群的个体形态差异不明显。松墨天牛形态特征与经纬度、海拔、气候要素相关分析结果表明,体长、体宽与经度、海拔、纬度、年平均降水量呈正相关关系,与年平均气温呈负相关关系。【结论】重庆市松墨天牛地理种群间尚未出现明显的分化差异,形态差异主要由环境因素的变化引起。

[Purposes]To investigate the morphological variation of Monochamus alternatus population in different geographic populations of Chongqing and their relationship with environmental factors. [Methods]Observation of 107 morphological characteristics of individual M. alternatus collected from 12 districts and counties in Chongqing was performed on individual body length, body width, pronotum length, pronotum width, and pronotum streak. According to geographical information and climatic elements of these specimen collection sites, M. alternatus in Chongqing was divided into 6 natural geographic populations. The variation and correlation of morphological measurement within and between populations, and the correlation between morphological variation and environmental factors was also analyzed. [Findings]The individual morphological variation and the coefficient of variation among populations of M. alternatus are low. The population’s morphology of the northwestern region of Chongqing is different from the other five populations. The accuracy of the comprehensive discriminant function is low. The difference is not obvious. Correlation analysis between the morphological characteristics of M. alternatus and the climatic elements showed that the body length and width of M. alternatus were significantly positively correlated with longitude, altitude, latitude, and average annual precipitation, and significantly negatively correlated with the average annual temperature. [Conclusions]The M. alternatus in Chongqing has not differentiated into obvious geographical differences. The morphological differences are caused by changes in environmental factors.