Studies On High Yielding Molecular Bases And Physiologic Traits In Indica-japonica Hybrid Rice

24 indica-japonica hybrids or japonica-japonica hybrids, recently bred by different breeding uints in Zhejiang provice, were collected to analysis by In Del moleculer marker techniques. The indica-japonica attribute, cluster of genetic similarity, principal component analyses, testing of yields and agronomic character, heterosis analysis were conducted in present paper. Meanwhile,indica-japonica hybrid rice Zheyou18 and Yongyou12 were s investigated on growth vigor in seeding stage, chlorophyll contents, photosynthetic capacity of flag leaves, yield composition factors and panicle morphology. Results were as follows:Eighteen pare of In Del primers could amplify to all materials to obtain special indica bands,japonica bands and indica-japonica hybrid bands. According calculated the frequency of japonica genes, these materals were accurately judged different indica-japonica attributes, and were divided into six clusters, twelve hybrids belong to indica-japonica hybrids, and another thirteen hybrids into japonica-japonica hybrids. Again using cluster analysis of In Del markers, this distribution was verifed.PCA analysis shown that all varieties classify non-overlaping three zones, ie, indica zone, typical japonica-japonica zone, japonica cline-intermediate type zone.Comparision on the average of plot yields in two-year trials, it were shown that the yields of indica-japonica hybrids increase by 12.47% and 14.89% than that of japonica-japonica hybrids, exert outstanding yields advantages. Upon analysis of ten agronomic character between two type hybrids,total spikelets and fertile spikelets of indica-japonica hybrids were significantly increased by about 30%,It was suggested that larger panicles is the majore contribution factors to yields increase. After reckoned the genetic(GD) distances of tesed varieties to control Jiayou 2, the average of indica-japonica hybrids were more than that of fjaponica-japonica hybrids in two-year trials, it hint that the indica-japonica hybrids could increase in yiels to control are correlation with to lager In Del genetic distances. Indica-japonica hybrids express stronger vigor in seedling stage, for example, varity Zheyou18 express more advantages in seedlings height and roots dry weight. About on photosynthetic capacity,transpiration rate(Tr) and stoma conductance(Gs) of flag leaves of Zheyou18 were highest than that of other varieties, and net photosynthetic rate(Pn) was kept a highest increasing rate during later growth phase. It will provide the lager “BNAK” of indica-japonica hybrids with more photosynthetic products.But the chlorophyll contents of indica-japonica hybrids in whole growth phase had no dominance to others.Comparison of the morphology of top three leaves, the flag leaf angle of Zheyou18 was of minimum and total areas of top three leaves of Zheyou18 and Yongyou12 were of maximum, the control heterosis of Zheyou18 was from 16.46% to 38.59%, and of Yongyou12 was 21.70% to44.82%. These heteroses were relation to the leaf long of top three leaves. Analyses on agronomic characters and yield composition indicated the spikelet number per panicle of Zheyou18 and Yongyou12 were maximum, means they were super-large panicle variety. According to the morphology of primary and intermediate panicle, the numbers of first branch of primary and intermediate panicle of Zheyou18 and Yongyou12 were profoundly superior to others and maintained constant spikelet numbers of first branch from largest to intermediate panicle, it resulted in such super large panicle type.