Abstract: The diversity of leaf, petiole and nut in 3 wild intraspecific populations (the Qinling Mountains ecotype, the Taiyi Mountains ecotype, and the Yanshan Mountains ecotype) of Castanea mollissima Blume were investigated to provide the scientific basis for resource protection and utilization. The results indicated: ①There were significant difference among and within population. The morphological traits, such as leaf length, width, leaf shape index, length of petiole and nut shape, size, color, have great morphological diversity with variation coefficient (CV) of more than 10%. The range of nut weight varied from 1.69g to 3.89g in Qinling population with CV 18.3%. The range and CV of leaf area and nut weight were the largest, and those of leaf shape index were the smallest; ②The content, of main nutrition composition (water, total sugar, starch, protein, fat, ash and Vc) in ripe nuts determined in obtained 118 seedlings at the Qinling Mountains, Taiyi Mountains and Yanshan Mountains was analyzed and presented considerable genetic variations with CV of 6.2％-28.3％, and the range and CV of the protein were the largest. There were the same trends in the 3 wild intraspecific populations; ③There was significant difference between site conditions, with smallest CV in leaf area and nut weight and highest CV of Vc content; ④Correlation analysis revealed that mean weight of a single nut with annual rainfall and the longitude of each ecotype, in contrast, they were negatively correlated with the altitude. Vitamin C contents in the nuts from different ecotype were negatively regulated with annul rainfall. These relationships indicated that environmental conditions had impact on genetic diversity in Chinese wild chestnut.

Key words: Castanea mollissima Blume, Morphological character, Genetic diversity, Variation