Comparison of New Hybrid Rice Combinations of R470 in Growth Characteristics and Yield heterosis

The differences of growth period,plant height,tiller characteristics,ear characters and yield heterosis were compared in four super high yield hybrid combinations and their parent R-line.The results showed that the traits of combinations had some differences.Superiority of the tilling charactersistic,spike-rate,grain structure and yield of four hybrid combinations which derived from the identical restorer line were different.Competition heterosis of RongYou 470 was the most remarkable,TianYou 470 and GYou 470 the next.The differences of over-parent heterosis between the other two combinations and the parent R470 were not remarkable except RongYou 470.