Abstract: To investigate the variation patterns of fresh weight and cold tolerance traits in new breeding materials of Pennisetum purpureum， identify the main trait factors affecting fresh weight， and select superior materials with high fresh weight and strong cold tolerance， this study used 86 materials of P. purpureum as experimental subjects and analyzed twelve traits for diversity， correlation， regression， path， cluster and principal component analysis. The results showed that the coefficient of variation for each trait of the tested materials ranged from 6.45% （leaf length） to 18.17% （tiller number after regreening）， and the genetic diversity index ranged from 1.8992 （plant height） to 2.0958 （fresh weight）. Regression and path analysis indicated that regreening speed， leaf length， internode length， and stem diameter had significant direct positive effects on fresh weight. Cluster analysis classified the materials into four clusters， with cluster I exhibiting better comprehensive traits and cluster IV the worst. Principal component analysis extracted three principal components， with a cumulative contribution rate of 68.12%. Based on principal component scores， the comprehensive evaluation D value was calculated using the fuzzy membership function method combined with the contribution rates. According to the D value ranking， 17 P. purpureum breeding materials with relatively superior comprehensive traits， including GM1×F-Y189， GM1×F-Y557， and GM1×F-A591， were selected. These results can provide a phenotypic evaluation basis for breeding new high-fresh-weight and cold-tolerant P. purpureum varieties.

Key words: Pennisetum purpureum, Yields, Cold tolerance, Comprehensive evaluation

摘要： 为探究象草（Pennisetum purpureum）育种新材料产量与抗寒性状的变异规律，明确影响产量的主要性状因子，筛选高产、抗寒性强的优良材料，本研究以86份象草材料为试验对象，对其12个性状进行多样性、相关性、回归、通径、聚类及主成分分析。结果表明：供试材料各性状变异系数介于6.45%（叶长）~18.17 %（返青苗数）之间，遗传多样性指数介于1.8992（株高）~2.0958（单株草产量）之间。回归与通径分析结果显示，返青生长速度、叶长、节间长及茎粗对单株草产量具显著正向直接效应。聚类分析将供试材料划分为4类，其中第Ⅰ类群综合性状较优，第Ⅳ类群较差。主成分分析提取出3个主成分，累计贡献率达68.12 %。基于主成分得分，结合模糊隶属函数法与贡献率计算综合评价D值，依据D值排名筛选出GM1×F-Y189、GM1×F-Y557、GM1×F-A591等17份综合性状表现较优秀的象草育种新材料。研究结果可为象草高产抗寒新品种选育提供表型评价依据。

关键词: 象草, 产量, 抗寒, 综合评价