Comparison of Photosynthetic Characteristics and Antioxidant Systems in Different Wheat Strains

To gain better wheat (Triticum aestivum L.) varieties for planting in Sichuan province, we compared the differences in the photosystem II (PSII) and antioxidant defense system at the blooming stage in 20 different new wheat strains collected from the wheat regional trial of Sichuan province in the year 2015. According to all measured data, we found that one of the strains, CD012J1, presented the highest photosynthetic and antioxidant enzyme activities, and a lower level of reactive oxygen species (ROS) than other wheat strains. In contrast, Chuan12147 had a lower photosynthetic rate and accumulated a higher level of ROS compared with other wheat strains. At the same time, we also found that wheat strains SH1103, 12C, XK322-1, and 13B4 had better photosynthetic capacity compared with Chuan12147. Correlation analysis indicated that wheat yield was significantly correlated with chlorophyll fluorescence parameters: the maximum efficiency of PSII photochemistry (F (v)/F (m)), the quantum yield of PSII electron transport, and the non-photochemical quenching coefficient. In addition, immunoblotting analysis indicated that Chuan12147 presented the highest levels of PsbS protein in six different wheat strains. Taken together, our results suggest that CD012J1 and Chuan12147 have the best and worst photosynthetic capacity and antioxidant systems, respectively. Moreover, F (v)/F (m) and PsbS protein could be used as a marker in breeding of wheat varieties.