20份欧洲型黄瓜种质资源的半致死温度与耐热性研究

Study on Semi-lethal Temperature and Heat Tolerance of 20 European-type Cucumber Germplasm

为探讨不同欧洲型黄瓜种质资源对高温的适应性差异,为耐热种质资源筛选及耐热机理的深入研究提供理论和实践依据,以20份欧洲型黄瓜的叶片为材料,设置6个高温处理,以室温为对照,测定浸提液电导率值并计算相对电导率,通过拟合Logistic方程,计算半致死温度（LT50）。试验结果表明,随着温度升高,相对电导率呈“S”型曲线,且相对电导率与处理温度存在显著的直线相关关系,通过计算“S”型曲线拐点求得20份欧洲型黄瓜的半致死温度在45~51℃,其中33-2的半致死温度最高,达到50.09℃,37-1的半致死温度最低,为45.82℃。20份欧洲型黄瓜的耐高温能力由强到弱依次为33-2〉75-2〉32-2〉33-1〉11-2〉31-2〉09-2〉36-2〉76-1〉36-1〉37-2〉10-1〉35-2〉76-2〉11-1〉43-2〉35-1〉75-1〉32-1〉37-1。因此,半致死温度可作为评价欧洲型黄瓜耐热性的一个可靠指标。

The purpose of this study is to discuss the adaptability difference of different European-type cucumber germplasms to high temperature, and provide theoretical and practical basis for the screening of heat tolerance germplasms and further research on the mechanism of heat tolerance. Taking 20 European-type cucumbers leaves as the materials, six high temperature treatment and one normal temperature treatment （as the control） was carried out, the relative electrical conductivity was calculated by measuring leach liquor conductivity, and the semi-lethal temperature was calculated by fitting the Logistic equation. The resuhs showed that the S curve of the relative electrical conductivity was observed along with the temperature rising, there was a significant linear correlation relation between the relative electrical conductivity and the temperature. By calculating the S curve inflection point, the semi-lethal temperature of 20 European cucumber was found to be between 45-51℃. Among them, LTs0 of 33-2 was the highest （50.09~C）, LT50 of 37-1 was the lowest （45.82℃）. The heat resistance of the 20 European-type cucumbers followed the order： 33-2〉75-2〉32-2〉 33-1 〉 11-2〉31-2〉09-2〉36-2〉76-1 〉36-1 〉37 -2〉 10-1 〉35 -2〉76-2〉 11 - 1 〉 43-2〉35-1 〉75 - 1 〉32-1 〉37 - 1. Therefore, the semi-lethal temperature can be used as a reliable index to evaluate the heat tolerance of the European-type cucumbers.