高丹草农艺性状与产量的相关和通径分析

目的] 明确对高丹草产量影响较大的关键农艺性状,挖掘其高产潜力,为品种选育及推广应用提供依据。方法] 以12份高丹草材料为研究对象,对高丹草各性状进行测量,利用随机区组试验对高丹草主要农艺性状与单株干重进行相关性、主成分和通径分析。结果] 各农艺性状的变异系数范围为11.61%~54.67%,表明各供试材料主要农艺性状存在丰富变异;各性状与单株干重相关性为株高>茎粗>叶片数>叶长>叶宽,单株干重与株高相关系数最大（0.746）,与叶宽的相关系数最小（0.349）;主成分分析共获得3个主成分,分别是株高因子、分蘖因子和叶宽因子,主成分分析中前3个主成分贡献率分别为45.855%、12.924%、11.594%,累计贡献率高达70.373%,主成分1中各性状特征向量值均为正值,单株干重、株高、茎粗、叶片数和叶长的载荷量较高,表明植株高大、主茎粗、叶片数多且植株叶片较长时,高丹草产量较高;通径分析中对植株产量直接影响的大小为株高（0.444）>茎粗（0.258）>叶片数（0.201）>叶宽（0.136）。结论] 株高和茎粗是直接影响高丹草单株产量的重要性状。

Correlation and Path Analysis Between Agronomic Traits and Yield of Sorghum-Sudan Hybrid Grass

Objective] To identify the key agronomic traits that greatly influence the yield of Sorghum-Sudan hybrid grass, unlock its high-yield potential, and lay the foundation for variety breeding, promotion, and application. Method] The agronomic traits of 12 materials of Sorghum-Sudan hybrid grass were measured. The correlation, principal component, and path analysis between main agronomic traits and dry weight per plant were performed using a random block test. Result] The coefficient of variation of the different agronomic traits ranged from 11.61% to 54.67%, showing that the principal agronomic traits varied widely across the materials evaluated. The correlation between the evaluated agronomic traits and dry weight per plant were plant height > stem diameter > number of leaves > leaf length > leaf width. The strongest correlation coefficient（0.746） was found between dry weight per plant and plant height, whereas the least （0.349） was found between dry weight per plant and leaf width. Principal component analysis yielded three main traits: plant height, tillering, and leaf width. In principal component analysis, the contribution rates of the first three were 45.855%, 12.924%, and 11.594%, respectively, with a cumulative contribution rate of 70.373%. In principle component 1, the eigenvectors of the evaluated agronomic traits were all positive, and the load of dry weight per plant, plant height, stem diameter, number of leaves, and leaf length was higher. This means that high yield of Sorghum-Sudan hybrid grass was achieved when the plant was tall, the main stem was thick, the number of leaves was large, and the plant leaves were long. In path analysis, the direct effect on plant yield was plant height （0.444） > stem diameter （0.258） > number of leaves （0.201） > leaf width （0.136）. Conclusion] Plant height and stem diameter are essential agronomic traits that have direct impacts on a single plant′s yield of Sorghum-Sudan hybrid grass.