不同营养部位、树龄银杏叶黄酮含量的比较

对银杏不同营养部位、树龄的叶黄酮含量的测定结果表明:不同营养部位叶黄酮含量的变化规律为长枝>中短枝>树冠>短枝,枝条上部叶>中部叶>下部叶,长枝上的叶黄酮含量为顶部叶>中部叶>基部叶,树冠上、中、下部叶黄酮含量呈现高-中-低的变化规律。不同树龄的银杏叶黄酮含量随树龄的增长呈递减趋势,尤其是15年以上成年大树黄酮含量下降的更加明显,几乎是幼龄小树的1/2。同时还对不同时期的银杏叶黄酮含量进行了测定,结果表明,银杏叶黄酮含量以10月份最高。因此,以叶用栽培为目的的银杏,应以10月份采摘为宜。

Comparison of the Contents of Flavone of Ginkgo Leaves of Different Location and Age of Tree

The contents of flavone of ginkgo leaves of different location and age of tree were measured and the results were as follows: the flavone contents of leaves of different location were long branches>medium and short branches>tree crown>short branches;upper leaves>middle leaves>lower leaves;as for long branches,the flavone contents of leaves were top leaves>middle leaves>lower leaves;the flavone contents of upper,middle and lower leaves on the crown reveaed the tendency of high-medium-low.The flavone contents of leaves of different ages of tree decreased as the trees grow older,especially that the leaf flavone contents of adult trees,which was only half of that of young trees,decreased dramatically.Furthermore,the flavone contents of leaves of different period were measured and the results showed that the leaf flavone contents were highest in October.Thus,for leaf use,the leaves should be pick in October.