银杏落叶前夕叶片和枝干生理生化物质变化规律的研究

Study on Change Regulation of Physiological and Biochemical Substances in Leaves and Branches Before Defoliation of Ginkgo biloba L.

以秋季落叶前夕的银杏雌雄植株为试材,研究分析了银杏落叶前夕体内叶片光合色素和保护酶活性的变化规律,以及叶片和枝干有机和无机营养的转移情况。结果表明:在银杏落叶前夕,无论雌雄植株其叶绿素含量和过氧化物酶(POD)活性均逐渐降低,类胡萝卜素含量和超氧化物歧化酶(SOD)活性在前期略有上升然后逐渐下降;叶片的淀粉、可溶性糖及可溶性蛋白质含量均显著降低,而茎干的含量则均显著升高;叶片的总氮和总磷含量略有降低,茎干的含量则相应升高;而叶片和茎干的钾含量变化不明显。因此,在银杏落叶前夕,随着叶片的衰老,叶片光合色素含量和保护酶活性逐渐降低,叶片中有机营养和氮、磷元素会转移到枝干中,减少了脱落的叶片中营养物质的浪费,为过冬储备了更多的能量。

Taking male and female ginkgo before defoliation as materials, the changes of photosynthetic pigment and protective enzymes activity as well as the change regulation of organic and inorganic nutrients were studied, in order to investigate the changing rule of the physiological and biochemical substances in ginkgo leaves on the eve of nutrient transfer and blade. The results showed that during the autumn,before leaves falling down,the chlorophyll content and POD activity reduced gradually in both female and male plants, whereas carotenoid content and SOD activity increased slightly first and then decreased gradually before defoliation. Starch,soluble sugar and soluble protein contents in leaves also reduced significantly,whereas these contents in branches increased si^ificantly. Total nitrogen,phosphorus contents in leaves decreased slightly and the contents in branches rose correspondingly, whereas potassium content in leaves and branches had no significant change. Therefore,before leaves falling down,photosynthetic pigment contents and protective enzyme activities of ginkgo leaves reduced gradually with the senescence process of leaves; organic nutrition, nitrogen content and phosphorus content will transfer from leaves to branches. This ensured to reduce nutrient waste by fallen leaves and reserved more energy for the plant in winter.