【摘要】 将49份具有代表性的我国狗牙根〔Cynodondactylon(L.)Pers.〕种源的离体叶片进行模拟低温处理,用电导法测其电导率,将电导率拟合Logistic方程,计算出狗牙根各种源叶片的半致死温度(LT50)。回归分析的结果表明:各种源的LT50与其所在的经纬度呈显著的线性关系,线性回归方程分别为Y=-31.3797+0.1478X和Y=-10.7982-0.1420X。依据LT50的变化,可将这49份狗牙根种源分为3大类,即低温敏感型(LT50≥-10℃)、过渡型(-18℃<LT50<-10℃)和耐寒型(LT50≤-18℃),3类狗牙根的分布具有一定的规律性。对狗牙根的耐寒机理也进行了探讨。更多还原

【Abstract】 <Abstrcat> Leaves of 49 accessions of \%Cynodon dactylon \%(L.) Pers. were treated under simulate low temperature in the freezer. Electrolyte leakage rate were measured and LT\-\{50\} were calculated. The results of linear regressive analysis indicated that the LT\-\{50\} \%vs. \%longitude and latitude are both proved to be notably linearly correlated. The equations are \%Y\%=-31.379 7+0.147 8\%X\% and \%Y\%=-10.798 2-0.142 0\%X\%. According to the LT\-\{50\}, three types of \%C. dactylon \%were determined, that is, low temperature sensitivity type (LT\-\{50\}≥-10℃), transition type (-18℃<LT\-\{50\}<-10℃) and low temperature tolerance type (LT\-\{50\}≤-18℃). And regularity is found in the distribution of the three types. This paper also inquired into the mechanism of low temperature tolerance reflected by LT\-\{50\}.更多还原