应用Logistic方程确定辣木的抗寒性

Low-temperature Tolerances of Moringa spp. Determined by a Logistic Model

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（LT₅₀），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（LT₅₀）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’。

Abstract: 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 > Moringa oleifera, indicating their abilities to resist low temperatures.