| Heterosis utilizing is the basic success experience of hybrid rice breeding in China.Filtrated the parents of having favorable photosynthetic characteristics,it is effective way to further utilize the heterosis in cultivate high-yielding hybrid varieties.As the distinct differences of different sub-species in many photosynthetic physiological characteristics of rice such as photorespiration,photosynthetic effficiency,photosynthetic stage,etc.A theoretical basis was existed for heterosis utilizing of sub-species rice.Genetic diversity of rice breeding genealogy between Indica and Japonice subspecies which contained 25 parents and 36 cultivated lines with 18 years and 4-selected phases by the Agricultural Science Institution of San Ming was analyzed with ILP markers,the net photosynthetic rate(Pnmax),the rate of water transpiration(TRAN),stomatal conductance(COND),and other traits of indica-japonica's differentiation of different types of materials in the heading stage and maturity were studied by comparative analysis,which reflect the characteristics of indicators of photosynthesis.Based on the molecule clustering result,8 cultivated restorer lines,which matched with 8 rice male sterile lines applying in big area in production,were selected.According to imperfection double cross design(8×8),a suit of genetic materials including 2 generations of parents and F1 was selected.With the Addictive-Dominant genetic model(AD model) and Statistical Analysis Methods(SAM),the performance of the genetic effect of different type's materials photosynthetic characteristics and genetic correlation of the yield traits were analyzed systematically.The main research results are as follows:1.The indica-japonica's variety were tested by using 58 SSILP specific markers.A further detection of differentiation's degree between indica and japonica was made among 59 parents and offsprings by using 48 primers,According to the Japonica's element index and Chen's comprehensive to determine analysis,The results show that:for ketanNangka,Jiananjing,02428,Chaoyin No1,Nipponbare,92gk729 6 varieties were divided into Japonica;for 47 Japonica,MHR18,9308,C418.Minghui413,97gk419 16 varieties were classified as partial japonica type; for Minghui 72,Minghui 63,Gui630,R527,Minghui 70 28 varieties were divided into the partial indica;for Duoxi No1,93-119 varieties were classified as indica.2.In this study,all sites on the genome DNA of all species tested was found the differentiations of indica-japonica,and typical correlation analysis showed that the ILP and morphological indices have a better fit.ILP was able to distinct the proportion of ingredients and parental genetic differences between indica and Japonica varieties respectively.3.According to the ILP marker's data,the main traits of photosynthetic characteristics measured from the full heading time to maturity indicated that the Pnmax of japonica→japonicaclinous→indicaclinous→indica showed an obvious increasing trend and the TRAN showed an obvious reducing trend.But during the maturity,the cases are on the contrary.The COND increased in different varieties from the full heading time to maturity,but the range of changes was different remarkably.In the full heading time and maturity,the little change of COND in japonica,the relatively large of COND in japonicaclinous and indicaclinous,and the greatest change of COND in indica.These indicated that photosynthesis weakened obviously in Indica in maturity and the forming of photosynthetic product mainly rely on the photosynthesis in the full heading time,and the main materials were operated and absorpted in the maturity.While Japonica still maintain a certain photosynthesis in maturity with the longer photosynthetic function period.The water use efficiency(WUE) of japonica→japonicaclinous→indicaclinous→indica showed an increasing trend in the full heading stage,which is just contrary to that of maturity.These results above show that there are differences in many photosynthetic physiological characteristics of different differentiation varieties.Indica has the higher Pnmax in the full heading time,while Japonica has a longer photosynthetic function.4.Significant differences in the phenotypic value of yield and main photosynthetic characteristics are existed between the two generation of different restorer lines and F1 which are both affected by additive and dominant effects.In the genetic effect,the dominant variance ratio of Pnmax and TRAN reached extremely significant level in the full heading time and maturity, and significantly greater than the additive variance ratio.It indicated that the Pnmax and TRAN in various varieties are mainly affected by the dominant effect.The additive variance ratio of COND and WUE reached significant level in the full heading time,which showed that it was mainly controlled by the additive effect;but in the mature stage,the COND and WUE of different varieties had no significant difference.5.The heritability analysis of main photosynthetic characteristics showed that except the broad heritability of WUE in maturity,the other photosynthetic characteristics have a significant or very significant level,with the higher broad heritability of Pnmax(79.5%),TRAN(83.0%), WUE(78.7%) as well as the Pnmax(74.5%) in maturity respectively,In addition to the narrow heritability of WUE in maturity,the rest of photosynthetic characteristics reached a significant or very significant level,which indicated that traits was easily transferred to generations.with the higher narrow heritability of the mature TRAN(22.5%) and the Pnmax(19.6%) in the full heading time,respectively.6.The significant differences in the genotype value of 1000-grain weight of F1 and the mature Pnmax showed that the obvious genetic differences were existed between the Pnmax and 1000-grain weight in various varieties.
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