中国西南部野生狗牙根种质耐寒性初步鉴定

采用田间统计绿期法、电导率法和匍匐茎恢复生长法,对50份西南部野生狗牙根(Cynodon dactylon)和2份美国引进品种(Tifway和Tifeagle)进行耐寒性初步鉴定。结果表明:1)52份材料的绿期为277~306 d,Sau02033(越西)、Sau02040(自贡)的绿期最长;2)半致死温度(LT50)为-9.00^-1.72℃,Sau02014(金川)、Sau02040(自贡)的LT50最低;3)匍匐茎恢复生长率为18.05%~42.36%,Sau02012(金川)、Ly97021(遂宁)的恢复率最高;4)偏相关分析结果表明,其耐寒性与海拔显著正相关(P<0.05);5)将52份材料系统聚类分为A、B、C三类,耐寒性强弱表现为A>B>C,Tifway和Tifeagle被聚在C类,大部分野生材料的耐寒性高于这两个品种。综上可知,3种方法综合评定结果表明,Sau02040(自贡)、Sau02013(金川)、Sau02014(金川)、XZ2(察隅)耐寒性较强,具有良好的牧草和草坪草开发潜力,3种指标综合运用更能全面评价狗牙根的耐寒性。

Cold tolerance of native Bermudagrass germplasms in southwest China

The cold tolerance of Bermudagrass(Cynodon dactylon),including 50 native accessions in Southwest China and 2 introduced varieties(“Tifway”and“Tifeagle”),was studied using methods including the green period,semi-lethal temperature,and stolon regrowth experiments.The following results were obtained:1)A green period for the 52 accessions ranging from 277 days to 306 days,with Sau02033(Yuexi)and Sau02040(Zigong)having the longest green periods;2)Semi-lethal temperatures(LT50)ranged from-9.00℃ to-1.72℃,and the LT50 of Sau02014(Jinchuan)and Sau02040(Zigong)were the lowest;3)Survival rates ranged from 18.05% to 42.36%,and the survival rates of Sau02012(Jinchuan)and Ly97021(Suining)were the highest among all accessions;4)The results of the partial correlation analysis indicated that there was a significant correlation between the cold tolerance and altitude(P<0.05);5)52 bermudagrass accessions were clustered into three groups:A,B,and C,in which the cold tolerance was A>B>C.Both“Tifway”and“Tifeagle”were clustered into group C,whereas most of the native accessions showed a higher level of cold tolerance compared to the two introduced ones;6)According to the comprehensive results of the three methods,Sau02040(Zigong),Sau02013(Jinchuan),Sau02014(Jinchuan),and XZ2(Tibet)were the top performers,from which excellent forage and turfgrass can be obtained.The cold tolerance of bermudagrass could be better evaluated using the three reference indicators above.