应用电导法配合Logistic方程确定‘多福’甜椒的抗寒性

Measurement of Cold Tolerance in Capsicum Annuum ‘Duofu' Based on REC and the Logistic Equation

为利用低温半致死温度(LT50)快速鉴定评价甜椒的抗寒性,本研究以‘多福’甜椒叶片为试材,通过测定不同低温强度(12℃,8℃,4℃,0℃,-4℃)和不同处理时间(0 h,1 h,2 h,4 h,8 h,16 h,24 h)下的相对电导率(REC)变化情况,分析温度和处理时间对REC的影响,并拟合应用Logistic方程计算其LT50。研究结果表明,甜椒叶片REC随处理温度的降低和处理时间的延长呈现逐渐上升趋势,当低温处理8 h以上时,甜椒叶片REC均随着处理温度的降低而呈"S"形上升,其变化规律符合Logistic方程,拟合度R2在0.975~0.980范围内,由此计算出"S"形拐点对应的温度即为甜椒叶片的LT50,其值在6.36℃~8.71℃之间,这可作为鉴定评价甜椒抗寒性的重要指标,为进一步研究甜椒品种的抗寒性及抗寒品种的选育提供理论依据。

In order to rapidly identify the cold resistance based on the semilethal low temperature（LT50）, the leaves of Capsicum annuum‘Duofu＇were selected as the materials. Through measuring the changes of REC under different low temperature stresses（12℃, 8℃, 4℃, 0℃,-4℃） and different treatment time,（0 h, 1 h, 2 h, 4 h, 8 h, 16 h,24 h）, we analyzed the effect of temperature and treatment time on REC. The LT50 was calculated according to REC curves and Logistic equation. The results showed that REC of Capsicum annuum gradually increased following the decrease of temperature and the extension of treatment periods. When the treatment time was longer than eight hours, REC of Capsicum annuum increased as a S-curves with the decrease of temperature. The tendency of REC followed the Logistic equation, while the fitting degree was between 0.975 to 0.980. According to the S-curves and the Logistic equation, the temperature of S-curves inflection point was calculated, which was corresponding to the LT50 of Capsicum annuum. The LT50 of Capsicum annuum‘Duofu＇was between 6.36℃ and 8.71℃,which might be an important evaluation index for cold tolerance in Capsicum annuum and provide a theoretical basis for further study on the breeding of cold resistance and cold resistance varieties of sweet pepper varieties.