新疆狗牙根种质资源抗寒性初步鉴定

将112份狗牙根（Cynodon dactylon）材料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，计算出狗牙根各材料叶片的半致死温度（LT50）．并将6项形态指标及半致死温度进行相关性分析。结果表明：新疆狗牙根叶片半致死温度的变化范围为-11．67～-19．68℃，平均LT50为-14．84℃，变异系数为9．92％；新疆狗牙根种质资源各外部性状都存在不同程度的变异．其中叶层高度与株高变异最大．分别达到47．02％，34．89％；相关分析表明，LT50与叶长、叶宽、匍匐茎节间长及叶层高度间具有显著的负相关性（P〈0．05），而叶长与叶宽、叶层高度、匍匐茎节间长间具有极显著正相关性（P〈0．01）。

Preliminary Identification of Cold Resistance in Xinjiang Bermudagrass Germplasm Resource

Leaves of 112 portions of Bermudagrass materials were treated under simulated low temperature in the freezer. The conductivity was measured with conductivity method. The semilethal temperature （LT50） of leaves from Bermudagrass were calculated with conductivity logistic equation, then correlation analysis were done on the 6 morphological indexes and semilethal temperature（LT50）. The results indicated： The LT50 of Xinjiang Bermudagrass ranged from -11.67 ℃ to -19.68℃, average of -14.84 ℃,and coefficient of variation of 9.92%; The each external characters of germplasm resources of Xinjiang Bermudagrass had various degree variation, and the greatest variation had taken place in leaf height layer height and plant height,which reached 47.02% ,34.89% respectively;The correlation analysis showed that there were the significant negative correlation （P 〈 0.05） between LT50 and leaf length,leaf width,stolon internode length,leaf layer height,while there was a significantly positive correlation （P 〈 0.01） between leaf length and leaf width,leaf layer height,stolon internode length.