长白落叶松氮素营养及与生长的关系

不同季节测定了不同种源长白落叶松针叶中硝酸还原酶（NR）活力，氮素营养和氨基酸（AA）含量，分析了它们与生长的关系。结果表明，长白落叶松所含氮素营养以NH4－N为主，NO3－N和NO2－N含量很少。不同种源长白落叶松针叶中NH4－N和T－N（NH4－N＋N03－N＋NO2－N）含量与其NR活力呈极显著正相关。生长季初，长白落叶松针叶中氮素营养含量低，与生长呈正相关；生长季中后期，针叶中氮素营养含量高，与生长无相关性。不同种源长白落叶松针叶中AA含量的季节变化与氮素营养相似，但与生长无相关性。生长季初针叶中NR活力与不同种源长白落叶松生长呈显著正相关。初步研究表明，生长李初针叶中NR活力，NH4－N和T－N含量可作为生理生化指标用于长白落叶松种源早期选择。

NITROGEN NUTRITION AND ITS RELATIONSHIP WITH GROWTH IN LARIX OLGENSIS HENRY

Nitrate reductase (NR) activity and the content of nitrogen nutrition and amino acid(AA)were measured in different season, and their relationship with growth was analyzed. The results showed that most of the nitrogen nutrition of conifer of L. olgensis was NH4 - N, the content of NO3 - N and NO2 - N was very low. The content of NH4 - N and T - N(NO3 - N NO2 - N NH4 - N)correlated with NR activity positively in L. olgensis of different provenances. At the beginning of growth season, the content of nitrogen nutrition of conifer was lower in L. olgensis, and correlated with gorth positively;while those at the middle and end of growth season were higher, but had no relationship with growth. The seasonal variation of AA content was similar with that of nitrogen nutrition in L. olgensis, but had no relationship with growth. At the beginning of growth season, NR activity of conifer correaed with growth positively in L. olgensis of different provenances. Preliminary results indicated that at the beginning of growth season NR activity, content of NH4 - N and T - N maybe become physiological and biochemical indices of early provenance selection in L. olgensis.