Analysis of Yield Formation and Photosynthetic Traits of the Hybrid Combinations of Rice Restorer Line Yazhan

Objective To explore the yield formation and photosynthetic characteristics of restorer line Yazhan series hybrid combination of rice，the relationship between yield and yield components，and the contribution of photosynthetic related factors to yield，so as to provide technical support for the breeding of hybrid line restorer line and high-yield cultivation. Methods In this experiment，two restorer lines Yazhan and Huazhan were used as male parents，and eight sterile lines such as Nongxiang A were used as female parents.Eight groups of 16 hybrid combinations were prepared as experimental materials.Field planting and conventional water and fertilizer management were used to analyze the yield，composition factor，chlorophyll content，net photosynthetic rate and other factors of the hybrid combinations of the two restorer lines，so as to compare the characteristics of the two restorer lines and their differences in photosynthetic performance. Results The results showed that the yield of the other 6 hybrid combinations was higher than that of the corresponding Huazhan combinations except for the C Liangyou and Quanliangyou hybrid combinations，and the yield advantage of the hybrid combinations was generally stronger than that of the Huazhan combinations.Path coefficient analysis showed that the effective panicle number and 1 000-grain weight per panicle were the main factors affecting the yield formation of Yazhan series hybrid combinations，and the grain number and seed setting rate per panicle played a secondary role，and both reached a significant level.During the period from the tillering stage to the grain filling stage，the chlorophyll content of Yazhan and their hybrid combinations dropped faster than that of Huazhan and their hybrid combinations，but the absolute value of chlorophyll content was higher than that of Huazhan and their hybrid combinations all through to the filling stage，the net photosynthetic rate of Huazhan series hybrid combinations was higher than that of Yazhan in the earing stage，but in the tillering stage and filling stage，the net photosynthetic rate of Huazhan series combinations was generally lower than that of Yanzhan series hybrid combinations，which showed that in the filling stage higher net photosynthetic rate was the key to increased production.The differences in yield formation and mechanism of the combinations were also discussed from the perspective of sink-source relationship，photosynthesis and chlorophyll，and the research results were of certain reference significance for further breeding and improvement of the restorer lines，hybridization and high-yield cultivation of the hybrid combinations. Conclusion As a restorer line，Yazhan has a better combination advantage than Huazhan，and the yield of the hybrid combinations is higher than that of Huazhan.The cultivars with strong photosynthetic ability，tillering ability and late grouting ability should be selected for restorer line breeding.