棉花海陆回交群体盛铃期的光合特性及其生理基础

Photosynthetic and Physiological Characteristics of Gossypium hirsutum L.×Gossypium barbadense L.Backross Populations in Full Boll Stage

为探究棉花海陆回交群体盛铃期的光合特性及其生理基础,筛选海陆杂交后代高光效种质资源,以陆地棉‘系9’为母本、海岛棉‘新海16’为父本构建的115份BC4F2:4株系群体为研究对象,测定其在田间条件下的光合参数及生理生化指标,利用描述性统计、相关性分析、回归分析、主成分分析和聚类分析评价子代株系的育种潜力。结果表明,回交群体的15个性状变异丰富,变异系数在8.96%~51.09%,其中净光合速率、蒸腾速率、水分利用效率、胞间CO_(2)浓度、气孔导度、水蒸气压亏缺、丙二醛含量、可溶性蛋白含量和超氧化物歧化酶活性9个性状变异系数均在20%以上。相关性分析发现,海陆回交群体不仅在光合或生理生化指标各自内部存在显著相关性,在光合与生理生化指标之间也存在显著相关性,其中叶绿素相对值(soil and plant analyzer develotrnent,SPAD)与14个性状的相关性均达到显著水平。多元逐步回归分析构建出10个光合生理指标的最佳回归方程。主成分分析提取了5个主成分,累计贡献率达78.608%,第1和第4主成分有效解释群体生理指标,第2、第3和第5主成分有效解释群体光合性状。Ward.D层次聚类法将群体划分为4类,第Ⅰ、第Ⅱ、第Ⅲ和第Ⅳ类群占总材料的百分比分别为33.91%、10.43%、29.57%和26.09%,且第Ⅳ类群的30份材料是综合性状较好的棉花种质,可作为适合育种需要的高光效品系。研究结果为棉花高光效育种提供了理论依据及材料支撑。

In order to explore the photosynthetic characteristics and physiological basis of G.hirsutum×G.barbadense backcross cotton in the full boll stage,and to screen out light-efficiency germplasm resources in the progeny of islandupland hybrid cotton,taking upland cotton‘Line 9’as the female parent and sea island cotton‘Xinhai 16’as the male parent,the BC4F2:4 population consisting of 115 lines was constructed as the research object,and the photosynthetic and physiological traits under field conditions were measured to evaluate the breeding potential of progeny lines with the method of descriptive statistical,correlation,regression,principal component and cluster analyses.The results showed that 15 photosynthetic physiological traits had rich variation,with a coefficient of variation ranging from 8.96% to 51.09%,among which 9 traits with coefficients of variation of 20% or more including net photosynthesis rate,transpiration rate,water-use efficiency,intercellular CO2 concentration,stomatal conductance,water vapor pressure deficit,malondialdehyde,soluble protein,and superoxide dismutase.Correlation analysis revealed that there was not only a significant internal correlation,but also a significant correlation between photosynthetic and physiological indicators,and soil and plant analyzer develotrnent(SPAD)significantly correlated with all 14 traits.Multiple stepwise regression analysis constructed the optimal regression equations for 10 photosynthetic physiological traits.By principal component analysis,5 principal components were extracted and the cumulative contribution rate reached to 78.608%.Principal component 1(PC1)and PC4 were the effective basis for explaining the physiological indicators of the group,PC2,PC3 and PC5 were the effective basis for explaining group photosynthetic traits.The Ward.D hierarchical clustering method divided the population into 4 categories and the percentage of the group Ⅰ、group Ⅱ、group Ⅲ and group Ⅳ to the total materials were 33.91%,10.43%,29.57% and 26.09%,and the 30 materials of the group Ⅳ had good comprehensive traits cotton,which could be used as high light-efficiency lines suitable for breeding needs.The results of the study provided a theoretical basis and material support for high light-efficiency breeding of cotton.