Physiological response of two cultivars of Canna L. plants to environment changes in transitional season from summer to autumn | 2种美人蕉属植物对夏末秋初光温变化的生理响应

chinois. 研究在夏末秋初光温变化较大条件下美人蕉属植物的生理响应，为初秋美人蕉属植物的生产管理提供依据。2010-09-13-10-11，以2种美人蕉属植物“黄花美人蕉”和“兴芋-2”为试材，测定在夏末秋初光温变化较大条件下，其叶片含水量、干物质含量、叶绿素含量、相对电导率、丙二醛和蛋白质含量及3种保护酶（SOD、CAT、POD）活性的动态变化规律。夏秋之交，美人蕉属植物上部叶片的相对含水量变化较小，下部叶片的水分利用率降低，出现水分亏缺；随着季节的变化，2种植物叶片的含水量逐步降低，干物质含量不断增加；而叶绿素总量、叶绿素a和叶绿素b含量均呈现不断下降的趋势。2010-09-13-10-11，反映细胞膜透性的叶片相对电导率和丙二醛含量均不断上升，且10-11的上升幅度更大；可溶性蛋白质含量不断升高；上部叶片中的SOD、CAT、POD活性也逐步增大，并于10-11达到高峰，但下部叶片的3种酶活性却表现出先升高后降低的变化趋势。夏秋之交，美人蕉属植物上部叶片活性氧代谢平衡，叶片衰老迹象不明显；而下部叶片活性氧代谢失衡，叶片明显衰老，因此对美人蕉属植物应进行控水和摘除部分老叶以延缓叶片衰老。

anglais. Physiological response of Canna L. at transitional season from summer to autumn, when the light and temperature changed dramatically, was investigated in order to provide theoretical basis for the production. Taking “C. indica var. flava” and “Xingyu-2” as test materials, dynamic changing mechanism of relative water content, chlorophyll content, relative electric conductivity, malon dialdehyde (MDA), protein content, and three protective enymes (SOD, POD and CAT) were measured under natural climate changes. The relative water content of the upper leaves changed little, while that of lower leaves showed water deficiency even with enough water because efficiency of water application declined. The water content decreased and the dry matter content increased. As the environment changed, the total chlorophyll content, chlorophyll a (Chla) and chlorophyll b (Chlb) got lower. REC and MDA increased significantly, especially in mid October. Protein content increased constantly. And SOD, POD and CAT activities also increased in upper leaves, and reached high peak in mid October, that increased first and then decreased in the lower leaves. The active oxygen metabolism of upper leaves was in balanced state and had no significant senescence at transitional season from summer to autumn, while the lower leaves were the quite the opposite. So with the canna plants water should be controlled and old leaves removed in production.