通过对吉林省公主岭市10年（2009~2018）4月20日~5月10日期间地下10 cm平均地温进行统计分析，确立玉米萌发期耐冷鉴定的适宜温度为10℃。以81份玉米杂交种为试材，测定10℃低温胁迫下种子的发芽率、发芽指数、平均发芽时间以及相对值等6个性状，运用主成分分析计算耐冷综合D值，基于D值和相对发芽率综合评价玉米杂交种耐冷性。结果表明，主成分分析将6个萌发期低温下的单项指标综合成2个独立的综合指标，基于耐冷性综合评价D值和相对发芽率对81份杂交种进行聚类分析，均划分为耐冷性强、较强、中等、较弱、弱5类，二者吻合度较高，筛选出先玉1225、省原80、禾育35、翔玉998和良玉66等5份耐冷性极强的玉米杂交种，提出基于相对发芽率的单指标粗略鉴评和基于综合耐冷D值的多指标精准鉴评相结合策略。

The appropriate temperature for the identification of chilling tolerance at maize germination stage was established as 10℃, based on a statistical analysis of the average ground temperature of 10 cm underground in Gongzhuling, Jilin during April 20 th to May 10 th, 2009-2018. The germination rate, germination index, average germination time and relative values of 81 maize hybrids were measured under low temperature stress. Principal component analysis was used to calculate the comprehensive cold tolerance D value. Based on D value and relative germination rate, chilling tolerance of maize hybrids was comprehensively evaluated. The results showed that six single indicators at germination stage were synthesized into two independent comprehensive indicators by principal component analysis. Based on the D value of comprehensive evaluation of cold resistance and the relative germination rate, 81 hybrids were all divided into 5 categories by cluster analysis, which included excellent cold resistance, strong cold resistance, medium cold resistance, weak cold resistance and very weak cold resistance. Both have a high degree of coincidence. Five hybrids with strong cold resistance were screened out, including Xianyu1225, Shengyuan 80, Heyu 35, Xiangyu998 and Liangyu 66. A strategy was finally proposed to combine the rough evaluation based on relative germination rate with the precise evaluation based on comprehensive cold tolerance D value.

S513.037

吉林省农业科技创新工程人才基金项目（C92072212）、国家重点研发计划（2017YFD0300605）、人社部2016年高层次留学人才回国工作资助项目