电导率法及Logistic方程鉴定马铃薯材料的耐寒性

为评价马铃薯的抗寒能力,以18份马铃薯资源和47份马铃薯后代品系为材料,采用低温胁迫处理马铃薯离体叶片,测定其相应电导率,经Logistic方程拟合得出其半致死温度(LT_(50))。结果表明,供试材料LT_(50)介于-3.8~-1.0℃,材料间差异显著,随着处理温度的降低,供试材料相对电导率逐渐升高,均呈S曲线变化。根据LT_(50)聚类分析结果表明,供试材料分为低温敏感型、中间型、耐寒性较强3类,筛选出耐寒性强的2份资源及4份后代品系可作为耐寒育种材料。

Predicting Cold Tolerance of Potato Plants by Electric Conductivity Measurements on Leavesunder Low-temperature Stress

Eighteen potato cultivars and forty-seven strains were tested for their abilites to tolerate frost and freezing temperatures.Leaves freshly detached from the potato plants were exposed to low temperatures for electric conductivity measurement to derive the medium lethal temperatures,LT50 ,on each sample.As temperature was lowered,the relative electric conductivity of the potato leaves responded in a typical S function in a logistic equation.The LT50 obtained from the regression equation varied from -3.8℃ to -1℃.They significantly differed among different cultivars and stains.Based on LT50 ,cold resistances of the various potato cultivars and strains were predicted and clustered into 3 categories, sensitive,medium,and tolerant to freezing.Among them,the two cultivars and 4 strains most tolerant to freezing were preserved for breeding low-temperature resistant varieties in the future.