二系杂交小麦光合特性研究及杂种优势分析OA

To explore the photosynthetic characteristics and hybrid vigor of different two-line hybrid wheat combinations and their parental lines,this study utilized four wheat photo-thermal sensitive male sterile lines,four restoring lines,and the corresponding sixteen hybrid wheat combinations,along with a conventional wheat variety Zhongmai 175,as research materials.Under field planting conditions,we measured various photosynthetic parameters of wheat leaves,including net photosyn-thetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular CO2 concentration(Ci),and chlorophyll fluorescence parameters(Fv/Fm).We also investigated agronomic traits at ma-turity and analyzed the hybrid vigor and correlations between the photosynthetic characteristics and agronomic traits of hybrid wheat.The results indicated that there were significant differences in Tr and Ci among the male sterile lines,restoring lines,hybrid combinations,and the control,while differences in Pn,Gs,and Fv/Fm were not significant.The trends in photosynthetic characteristics of the male sterile lines and hybrid combinations were relatively similar from the booting stage to 20 days post-anthesis,with the highest values of Pn,Tr,Gs,and Ci observed at the heading stage for the male sterile lines,restoring lines,and hybrid combinations.The proportion of super-parental hybrid vigor combinations for photosynthetic characteristics ranged from 56.25％to 93.75％,with super-high parental vigor combinations ranging from 31.25％to 81.25％,and super-control vigor combina-tions from 12.50％to 93.75％,with Tr and Gs showing the most significant super-high parental and super-control advantages.For agronomic traits,the proportion of super-parental hybrid vigor combi-nations ranged from 50.00％to 100.00％;that of super-high parental vigor combinations and super-control vigor combinations ranged from 18.75％to 75.00％,and from 18.75％to 100.00％,respec-tively,with the spikes number per square meter and yield exhibiting the most significant super-high parental and super-control advantages.There was a highly significantly positive correlation between Gs and Ci in hybrid wheat,and a significantly positive correlation between Pn and Gs.Hybrid wheat showed a significantly negative correlation with Tr,Gs,and Ci of restoring lines,as well as a signifi-cantly negative correlation with Tr,Gs,and Fv/Fm of mid-parent values.Additionally,significantly positive correlations were found between ear length and flag leaf area,number of grains per ear and flag leaf area,number of grains per ear and ear length,yield,and thousand-grain weight.Pn,Gs,and Ci of hybrid wheat were significantly positively correlated with thousand-grain weight,while Gs and Ci were significantly positively correlated with yield;Tr was significantly positively correlated with flag leaf area,and Fv/Fm was significantly negatively correlated with ear length.These findings demonstrate that the photosynthetic characteristics and agronomic traits of two-line hybrid wheat ex-hibited significant hybrid vigor,and some photosynthetic parameters are positively correlated with yield traits,which can be used to guide the breeding of high-yielding and high-photosynthetic efficien-cy hybrid wheat combinations.