铁冬青雌雄株在低温胁迫下的响应及抗寒性差异

Physiological characteristics and cold hardiness between male and female plants of Ilex rotunda

为了明确雌雄异株植物铁冬青的抗寒机理和雌雄株抗寒性差异,对5年生铁冬青雌雄株的离体叶片进行低温胁迫处理,测定其相对电导率(REC)、丙二醛(MDA)、游离脯氨酸(Pro)、可溶性蛋白、氧化酶活性各项指标,结合Logistic方程计算出半致死温度(LT_(50)),结合隶属函数法综合分析其抗寒能力。结果表明:随着温度的降低,铁冬青雌雄株REC和MDA含量上升,Pro、可溶性蛋白含量、POD活性表现为先上升后下降的趋势,而SOD活性则逐渐下降;雌雄株各生理指标在数值上存在显著的性别差异(P<0.05),雌株的REC和MDA含量显著高于雄株,而Pro、可溶性蛋白含量和SOD活性则显著低于雄株,POD活性无显著差异;铁冬青雌雄株最低LT_(50)分别为-6.29℃和-9.37℃。半致死温度结合隶属函数法综合表明铁冬青抗寒性存在显著性别差异,即雄株的抗寒性强于雌株。

To ascertained the cold resistance mechanism and the gender difference of cold hardiness between male and female plants of llex rotunda, detached leaves from five years old male and female plants were collected and treated with various lower temperatures. The relative conductivity, malondialdehyde content, superoxide dismutase activity, soluble protein content and free proline content of each plant were measured in the winter. Calculated the lethal temperature by Logistic equation, and evaluated the cold-hardiness by the subordinate function, the result showed that The male plants were significantly cold hardier than that of the female plants and the LT50 for male and female plants were -9.37℃ and -6.29℃. With temperature decreasing, REC and MDA were increased and SOD activities were gradually dropped, but Pro, soluble protein content and POD were increased firstly than decreased. There were significant gender differences in physiological-biochemical indexes of male and female Rex rotunda plants （P 〈 0.05）. With temperature going lower, REC and MDA of female plants were higher than that of male plants and Pro content, soluble protein content and SOD activity were lower. No significantly POD activity differences were observed. The male plants of/. rotunda had much stronger cold-resistance than that of female plants. The REC, MDA, Pro, soluble protein content and SOD could be used as physiological indices to evaluate cold hardiness of ornamental plants.