榧树变异类型的初步研究

Preliminary analysis on special Torreya individuals

长期的栽培过程中,笔者在省内实生群体发现零星分布着一类生长迅速的榧树变异类型。本研究采用SRAP分子标记体系对榧树速生变异类型与榧属其他5个种、2个栽培变种(香榧、云南榧、巴山榧、九龙山榧、日本榧、榧树、长叶榧)等共21个样品进行了分析。结合叶形指数的方差分析和SRAP分子标记分析结果,进行了研究材料的亲缘关系聚类,探讨了系统发育关系。结果显示,榧属5个种、2个栽培变种及榧树变异类型的21个样品可以分为5组:长叶榧组、榧树变异类型组、包括香榧在内的榧树组、巴山榧、九龙山榧、日本榧组,而云南榧自成一组;榧树变异类型与长叶榧亲缘关系较近,其叶片形态偏向长叶榧;各种间叶形指数差异极显著,榧树变异类型的叶形指数显著不同于与其他样品。但推断本研究中榧树变异类型是长叶榧的自然变异,还是长叶榧与其他榧树的杂种,还有待深入研究。

Some special Torreya individuals （seedlings） was found in Zhejiang Province, which was sporadically distributed, but grows faster than common seedlings of T. grandis. With a modified SRAP analysis protocol, the phylogenetic relationship among 21 samples from 7 species or varieties of Torreya including T. grandis var. merrillii, T. yunnanensis , T. fargesii, T. grandis var. jiulongshanensis, T. nucifera , T. graendis, T. jackii and the special Torreya individuals had been studied, and their leaf shape index was referenced. It had been revealed that 21 samples of 7 species or varieties including the special Torreya individuals could be categorized into 5 groups, viz. the group of T. jackii, the group of the special Torreya individuals, the group of T. graendis including T. grandis var. merrillii, the group including Ti fargesii , T. grandis var. jiulongshanensis, T. nucifera and the group of T. yunnanensis. The special Torreya individuals were phylogenetic ally related with T. jackii in this research, and the special Torreya individuals were close to T. jackii in terms of leaf morphology also. But the special Torreya individuals were significantly different from the samples of other 7 species or varieties. How-ever, it was no enough confidents to concluded that the variants could be natural variation from T. jackii, or the hybrid between T. grandis and T. jackii, the further research would be remained needed.