应用Logistic方程确定辣木的抗寒性

摘要

以3个品种辣木嫩梢为试材,通过测定不同低温胁迫下电解质渗出率的变化规律,应用Logistic方程建立回归方程,确定其低温半致死温度(L T50) ,以此来判断不同品种辣木抗寒性强弱.研究结果表明,在低温胁迫下,随着辣木嫩梢处理温度的降低,电解质渗出率总体呈逐渐升高趋势,其中8 h和16 h低温处理的辣木电解质渗出率曲线均呈"S"形,满足 Logistic方程拟合要求,计算出的低温半致死温度(L T50)由低到高分别为'狭瓣辣木'、'PKM1'、'多油辣木',由此可确定辣木抗寒能力由强到弱依次为'狭瓣辣木'＞'PKM1'＞'多油辣木'.%Young shoots from three varieties of Moringa plants were used to determine their low-temperature tolerances .The electrolyte leakage rates of the leaves under cold stress were fitted in a logistic equation to calculate the semi-lethal temperature (LT50) for the plants . The leakage rates were found to increase with decreasing temperature .When the low-temp treatments last 8 or 16 hours ,the rate curves appeared in S-shape and fitted the model , LT50 were obtained . The calculated LT50 for the three cultivars decreased in the order of Moringa stenopetala＞PKM1＞ Moringaoleifera ,indicating their abilities to resist low temperatures .