紫外光辐射对不同条件下小麦叶片叶绿素降解作用的研究

EFFECTS OF ULTRAVIOLET RADIATION ON THE DEGRADATION OF WHEAT LEAF CHLOROPHYLL UNDER DIFFERENT CONDITIONS

研究了小麦叶片叶绿素在离体和非离体条件下受紫外光（２８０—４００ｎｍ）照射后的降解动态过程。用９５％，５０％的乙醇及丙酮溶液提取的小麦叶片叶绿素，经紫外光连续照射后发现，以５０％乙醇提取的叶绿素分子降解率最大，其次为９５％乙醇液，最小的是丙酮溶液。紫外光在白光条件下对有机溶剂提取的叶绿素的分解作用比在黑暗条件下要大。在非离体条件下，叶绿素经紫外光照射后降解速率比较缓慢。但紫外线在白光照条件下对叶绿素的分解作用比在黑暗条件下要小，表明紫外光对离体和非离体状态下的叶绿素的降解具有不同的作用机制。此外，本试验还使用Ｎ￣６—苄基腺嘌呤（６ＢＡ）对紫外线光解小麦叶片叶绿素的作用进行了试验和探讨。

The time course of the degradation of wheat leaf chlorophyll under different conditions ex-posed to UV radiation was investigated.Chl extracted in 50%ethonal solution exposed to the UVradiation showed the largest degradation,next was that extracted in 95%ethonal,and the least inacetone. The degradation of Chl extracted in organic solutions under white light was larger thanthat under dark,as the Chl in dark was more steady.Under intact condition,Chl treated by UVradiation was shown to be relatively low decomposition, but the degradation of Chl under whitelight was less than that under dark.It indicated the different mechanisms of wheat chlorophylldegradation under the different conditions. Furthermore,study of the influence of benzyladenosineon the degradation of Chl by ultraviolet radiation was also made in the present experiment.