Analysis On Combining Ability Of Photosynthetic And Main Agronomic Traits In Minghui 3301, An Elite Restoring Line Of Rice

Minghui 3301 is one of the best restoring lines of hybrid rice. The hybrids have super high yield capacity, when Minghui 3301 was crossed with many male sterile lines. In this study, 5 restoring lines (minghui3301, minghui86, minghui63, R527, mianhui436) and 5 male sterile lines(mingfengA, longtepuA, II-32A, 29A, tianfengA )were used to creat 25 hybrid rice by way of incomplete diallele cross (NCII)design, the hybrids were planted at Fuzhou and Shunchang in Fujian province respectively. Combining ability and inheritance of photosynthetic and the main agronomic traits of the hybrids were evaluated, the high yield and yield stability were also analysed. By the GCA multiple comparison, we evaluate the breeding utilization of the parents, especially minghui3301. Via this study the following conclusions were obtained:1 The correlation analysis showed that the relationship between yield and 8 photosynthetic traits are positive significant at 5% or 1% level. The relationship between yield and ci is negative significant at 1% level. In most of the photosynthetic related traits, minghui3301 has the highest GCA among the 5 restore lines. 3 minghui3301 combinations have very high photosynthetic SCA. So we can obtain hybrids with high photosynthetic traits easily , when minghui3301 was crossed with many male sterile lines.2 The relationship between yield and 8 stem or leaf traits hadn't positive significance at 5% level. Only the relationship between yield and the lengh of second leaf, stem width are positive significant at 5% level. It indicate that the difference of stem or leaf type are nolonger the main fators that influence the yield in this experiment.3 The correlation analysis showed that the relationship between yield and the numbers of secondary branch is negative significant at 1% level, and the relationship between yield and total spikelets per panicle, 1000 grain weight, effective panicle, filled grain per panicle, numbers of primary branch, seed setting rate, weight of per panicle were positive significant at 1% level.In the 5 restoring lines, the SCA of minghui3301 are higher than others in the traits what follow: effective panicle, total spikelets per panicle, filled grain per panicle, numbers of primary branch, weight of per panicle etc. So minghui3301 has high SCA in yield. But the SCA of the yield related traits of the combinations derived from minghui3301 are not always the highest, most of them are in the upper level. This mean that the superiority of combinations derived from minghui3301 dosen't consist of single factor, it is the result of coordinated development of many yield related traits.Variance analysis of two experimental sites shows that yields of the 5 combinations crossed by minghui3301 are in the top 10 of all 25 hybrids. The yield of longtepuA/minghui3301 is in the first place, mingfengA/minghui3301 is the second, II-32A/ minghui3301 is the third, tianfengA/minghui3301 is in the 8th place and 29A/minghui3301 is in the 9th place , the difference between the yield of II you ming 86 (super rice CK) and the 5 hybrids are positive significant at 1% level.Minghui3301 is proved to be an ideal super hybrid rice parent because of its high combining ability.