高粱种质材料光合特性和水分利用效率鉴定及聚类分析

以101份高粱种质为试验材料,在自然条件下利用LI-6400光合仪测定其叶片的光合参数并进行相关性分析,运用聚类分析和判别分析对不同高粱种质的光合特性和水分利用效率进行分类及综合评价。结果表明：高粱种质材料间叶片的光合参数（P_n、T_r、G_s、C_i）及水分利用效率（WUE）差异极显著（P<0.01）,其中净光合速率（P_n）的变幅为12.04~49.32μmolCO₂/(m ²·s)。相关分析表明,P_n与T_r（r=0.745）、P_n与G_s（r=0.654）、T_r与G_s（r=0.771）呈极显著正相关;P_n与C_i（r=-0.493）、T_r与WUE（r=-0.400）、C_i与WUE（r=-0.341）呈极显著负相关。通过对P_n、T_r和WUE等3个参数的测定结果进行聚类分析,101份种质材料划分为6个类群,其中A2类群和C类群的17份材料P_n和WUE均较高,可作为高粱高光效生理育种的亲本或改良材料加以利用;在聚类分析基础上运用判别分析对3个光合参数（P_n、T_r和WUE）建立了8个判别能力较高的判别模型。

Identification and Cluster Analysis of Photosynthetic Characters and WUE in Sorghum Germplasm

101 sorghum germplasms were selected as test materials in this study. The photosynthetic parameters in leaves were determined by LI-6400 photosynthesis instrument under field conditions, and correlation analysis was carried out. Photosynthetic characters and water use efficiency (WUE) of different sorghum germplasm were evaluated by cluster and discrimination analysis. The results showed there were significant differences (P<0.01) in photosynthetic parameters (P_n, T_r, G_s, C_i) and water use efficiency (WUE) among the test germplasm, with P_n ranging from 12.04 to 49.32μmolCO₂/(m ²?s). Correlation analysis indicated that the highly significant positive correlations were between P_n and T_r (r=0.745), P_n and G_s (r=0.654), T_r and G_s (r=0.771). The highly significant negative correlations were between P_n and C_i (r=-0.493), T_r and WUE (r=-0.400), C_i and WUE (r=-0.341). 101 sorghum germplasms were clustered into six groups based on P_n, T_r and WUE. The group A2 and C including 17 sorghum breeding materials with high photosynthesis rate and high water use efficiency could be utilized as high photosynthetic efficiency breeding parent or materials. Based on cluster analysis, that established eight discriminant models which were of high discriminative ability by discriminant analysis for three photosynthetic parameters (P_n, T_r and WUE).