褪黑素延缓红小豆叶片衰老的作用研究

Exogenous Application of Melatonin Delays Leaf Senescence in Adzuki Bean

为了明确褪黑素对红小豆叶片衰老的延缓作用,为提高红小豆产量和品质提供理论依据,试验分别采用2、20、200μg·m L-1浓度的褪黑素处理离体的红小豆复叶,用SPAD502手持式叶绿素仪和OSp+叶绿素荧光仪分别于处理后第0、2、4、6、8 d测定各处理叶片的叶绿素含量和光系统Ⅱ最大光化学效率(Fv/Fm)。结果表明,褪黑素处理的红小豆叶片中叶绿素含量和Fv/Fm明显高于对照,且随着褪黑素浓度的升高作用效果呈上升趋势。说明褪黑素可有效维持叶片中叶绿素的含量及叶片光系统II的完整性,进而推迟红小豆叶片的衰老进程。

The potential effects of melatonin on delay leaf senescence of adzuki bean were tested in the current study,which could be benefit to improve the quality and yields of adzuki bean. Detached compound leaves were treated with 2,20 and 200 μg·m L^-1 melatonin solutions, respectively. The chlorophyll content and the maximum potential photosystem II efficiency（Fv/Fm）were detected by using the SPAD502 and OSp＋ after 0,2,4,6 and 8 days treatment,respectively. The results showed that both of chlorophyll content and Fv/Fm of leaves by the melatonin treatment were significantly higher than the control,and the effect was positively correlated with its concentrations. It was suggested that the melatonin could delay adzuki bean leaf senescence by slowing down the chlorophyll content decrease and maintaining the photosystem II function.