7种木莲属植物抗寒性评价及其生理机制

Evaluation of Cold Resistance and Physiological Mechanism of Seven Manglietia Species

摘要:

为建立木莲属（Manglietia）植物的抗寒性综合评价体系，对7种木莲属植物扦插苗进行低温胁迫处理，测定叶片的抗寒性关键生理指标，拟合Logistic方程计算低温半致死温度，隶属函数法筛选抗寒性关键指标并综合评价。结果表明，7种木莲属植物的低温半致死温度依次为木莲 < 红花木莲 < 荷花木莲 < 巴东木莲 < 球果木莲 < 锥花木莲 < 粗枝木莲，且与相对电导率显著正相关。7种木莲属植物叶片的游离脯氨酸和可溶性蛋白含量及超氧化物酶、过氧化物酶活性均随温度降低呈先升后降的趋势，而可溶性糖和丙二醛含量则不断增加、后趋于平稳。聚类分析结果表明7种木莲可分为3类，木莲和红花木莲抗寒性较强；荷花木莲、巴东木莲和球果木莲抗寒性中等；粗枝木莲和锥花木莲抗寒性较弱。

Abstract:

In order to establish a comprehensive evaluation system for cold resistance of Manglietia species, the key physiological indexes of cold tolerance in seven cutting seeding were determined under low temperature. The fitting logistic equation was used to calculate the semi-lethal temperature of low temperature (LT₅₀), and the key indexes of cold resistance were screened and evaluated by membership function method. The results showed that the LT₅₀ of seven Manglietia species were in the order of M. fordiana < M. insignis < M. nucifera < M. patun-gensis < M. conifer < M. paruicula < M. crassipes, which had positively significant correlation with relative conductivity. With the temperature decrease, the contents of free proline and soluble protein, activities of superoxide dismutase and superoxide dismutase in seven Manglietia species fall after rising, while contents of soluble sugar and malondialdehyde increasing and gradually leveling off. The cluster analysis showed that 7 Manglietia species could be divided into 3 groups, cold resistance of Manglietia fordiana and M. insignis were stronger, M. nucifera, M. patungensis and M. conifera were medium, M. paruicula and M. crassipes were weak.