生长光强和冬季低温对三种亚热带木本植物生理特性的影响

EFFECT OF IRRADIANCE AND WINTER TEMPERATURE ON PHYSIOLOGICAL PROPERTIES OF LEAVES OF THREE SUBTROPICAL TREES

种植于１００％、４０％和１６％自然光下的荷木、黧蒴和黄果厚壳桂幼苗叶片，在冬季低温期中细胞电解质未发生明显泄漏．强光下的黄果厚壳桂的叶绿素荧光Ｆｖ／Ｆｍ只有０．３４．离休叶园片经５℃弱光处理，Ｆｖ／Ｆｍ下降．黄果厚壳桂在三种光下叶片的ｃｈｌａ／ｂ、可溶性糖／蛋白质和Ｆｖ／Ｆｍ皆比荷木和黧蒴低．显示其对高光和低温较为敏感．４０％光比其他两种光强较有利于三种植物中有机物的合成．

Seedlings of three subtropical forest species, Schima supeba, Cryptocarya concinna,and Castanopsis fissa, were grown under varied light conditions at 100%, 40% and 16% of nature sunlight intensity. During the winter time, the fully exmpding leaves in the top of the Plants were collected for determination of chlorophyll fluorescence,contents of chlorophyll, carotenoid, soluble protein and soluble sugar, as well as the permeability of cell membrane.All of the species exhibited acclimation to different irradiances and low temperature in winter. No considerable leakness of leaf electrolyte was observed, but the toeal electrolyte of leaf was declined at low irradiance.Chlorophyll fluorescence Fv/Fm ratio was slightly decreased (Scheime superba and Castanopsis fissa) or markedly decreased (Cryptocarya concinna) in leaves at 100% of irradinnce. Same trend of decreasing Fv/Fm value was found in three species after treatment for 9 hours with leaf discs at 5℃ and light intensity of 100μmol m-2s-1. The ratios of Chl a/b and soluble sub/protein and Fv/Fm were lower in Cryptocarya concinnathan in Schima superba and Schima superba and the former was susceptible to high light and low temperature, but the latter two species showed a higher ability of environmental acclimation.In comparision with 100% and 16% of irradiance, however, the similar ratio of soluble protein/Chl in three species, and more soluble sugar and plotein in leaves at 40% of irradiance showed that this light level favoured the normal synthesis of organic compounds durins winter season.