Genetic Study On Grian Quality Traits Of Indica Rice

The grain quality character of rice is a comprehensive character which have the complicated genetic constitutions. Deeply inquirying into the genetic law of each the grain quality character by choosing right genetic model and efficient statistical analysis methods will provide theoretical foundation for enhancing the breeding efficiency of rice quality.In this paper, genetic analysis was conducted to characterize the six rice quality characters by using the genetic model for cereal seed on the data obtained in incomplete diallel crosses with five indica male sterile lines and six indica restorer lines .The endosperm direct genetic variances of the six main rice quality characters were estimated. Further the genetic control of each the character were confirmed. Also the endosperm direct heritability, cytoplasmic heritability, maternal heritability were estimated. In addition, genetic effects of each rice quality character of all the genetypic materials were predicted. The results exhibited as follows:1.Genetic analysis of the milled rice percentage of indica riceThe milled rice percentage of indica rice was influenced mainly by endosperm nuclear genes and maternal nuclear genes. Maternal genetic effect was predominant for this trait. Maternal additive effect was more important than maternal dominant effect. Endosperm nuclear genes mainly influenced this trait with a form of dominant gene action. Maternal and direct dominant effect would simultaneously enhance or reduce the milled rice percentage.The heritability of this trait of indica rice was the maternal heritability primarily, estimated value for 49%. The direct and cytoplasmic heritability were insignificant.Predicted values of genetic effects indicated that the male sterile line II-32A and the restorer lines 21, 25, 32 and five hybridized combinations appeared to be useful for the improvement of the milled rice percentage.2.Genetic analysis of the whole rice percentage of indica riceThe whole rice percentage of indica rice was influenced mainly by endosperm nuclear genes and maternal nuclear genes. Maternal genetic effect was predominant for this trait. Maternal additive effect was more important than maternal dominant effect. Endosperm nuclear genes mainly influenced this trait with a form of dominant gene action. Maternal and direct dominant effect would simultaneously enhance or reduce whole rice percentage.The heritability of this trait of indica rice is the maternal heritability primarily , estimated value for 71%. The direct heritability and cytoplasmic heritability were not significant.Predicted values of genetic effects indicated that the male sterile line II-32A and the restorer lines 25,30 and four hybridized combinations appeared to be useful for the improvement the milled rice percentage.3.Genetic analysis of the grain length-width ratio of indica riceGenetic analysis of the grain length-width ratio of indica rice showed that the genetic effect that mainly affected this trait was the maternal additive effect. The maternal dominant effect play a minor role.The total heritability in the narrow sense estimated of this trait were 92%.Predicted Values of genetic effects indicated that the three male sterile lines D62A, mian5A, zhongjiuA, restorer lines 33 and ten hybridized combinations appeared to be useful for the improvement of the grain length-width ratio of indica rice.4. The chalky grain rate of indica riceThe chalky grain rate of indica rice was controlled by foregoing three sets of genetic control systems of which the direct genetic effect was predominant with the maternal genetic effect in the next place. The cytoplasmic effect is least. The direct genetic effect affected the trait with a form of additive gene action while the maternal genetic effect influenced it mainly with a form of dominant one. The maternal additive effect also was significantly influenced the trait. The residual variance value estimated suggested the trait was influenced by environmental factors on the small extent.The...