中文摘要：

为了比较鄂西南不同核用银杏品种叶中主要黄酮苷元含量,并进一步探讨影响其含量的因素,采用RPHPLC法对样品中黄酮苷元进行定量分析,同时采用德国elementar vario MICRO CUBE元素分析仪测定样品中碳、氮等元素含量。结果表明：不同银杏品种叶片中黄酮含量存在差异,三种主要黄酮苷元组成比例在各品种间差异更加显著,恩银15号及恩银23号具有较好苷元比例,可以作为叶用银杏发展的优先考虑品种。进一步分析表明,叶片总黄酮含量与叶中氮含量之间显著正相关,提示合理施氮有助于改善三种苷元的比例关系,从而使其比例达到最佳。通过比较鄂西南不同银杏品种银杏叶中有效成分的含量,为提高银杏叶质量,优化银杏叶资源提供了理论依据。

英文摘要：

To compare the contents of flavonoid ag]ycones in the leaves of Cinkgo biloba L. from different species in the southwest of Hubei province and to discuss the influential factors of environment. RP-HPLC was used to determine the ftavonoid agiycones. The contents of carbon,hydrogen and nitrogen were measured by elementar ratio MICRO CUBE analyzer. The results showed that the contents of flavonoids and flavonoid aglycones varied greatly from different species. Ratio of flavonoid aglycones in the leaves of EnG15 and EnG23 were better than others. Furthermoro,the flavonoids content and the corresponding nitrogen content was correlated positively. Appropriate nitrosen may help improve ratio of flavonoids component in the leaves of G. biloba. The results of this study may provide a basis for the optimization of the quality and resources of G. biloba.