Analysis Of Genetic Effects Of Tetraploid Reverted Diploid Progenies Of Indica Japonica Rice

To determine the characteristics and genetic distance of diploid progenies reverted by tetraploid derived from indica and japonica crosses in rice,In this study,50 diploid rice with doubled tetraploid recovery from the hybrid progenies of Nipponbare and 93-11 were used as test materials.52 agronomic characters such as flag leaf length,1000 grain weight and seed setting rate were measured.Correlation analysis,variation analysis,multiple comparison analysis,clustering analysis,SSR molecular markers,photosynthetic determination of some materials,yield measurement and rice quality detection were carried out,It lays a foundation for further establishing new rice breeding methods and breeding new excellent rice varieties,and also provides a new way for the utilization of tetraploid rice.The main research results are as follows:(1)The variation coefficient of main agronomic characters in the reply materials was 7.47% ～ 165.24%,among which the variation coefficient of the length character of the longest awn was the largest and the seed setting rate was the smallest.(2)The reply materials can be divided into five categories according to the ripening period: extremely early ripening,medium early ripening,medium late ripening and late ripening(3)The 53 materials(including diploid and tetraploid parents)were divided into three categories by phenotypic cluster analysis and SSR cluster analysis.The coincidence degree of the large categories was completely the same,but the coincidence degree of the small categories was different.(4)The multiple comparative analysis of characters showed that the materials with significant differences in flag leaf width between the reply materials and the parents(93-11,Nipponbare,and the tetraploid of the hybrid offspring of 93-11 and Nipponbare)were the most,with 30 copies,and the materials with significant differences in the angle and tongue length of the second leaf were the least,with only one copy.(5)The results showed that the highest yield of 11 materials was 56.43% higher than that of the control materials at the same ripening stage;The rice quality of the two materials reached the national second-class high-quality rice quality standard.(6)The results of photosynthetic rate measurement showed that the net photosynthetic rate of some restoring materials was significantly higher than that of their parents.The average net photosynthetic rate of one material was 8.84% higher than that of 93-11,11.38% higher than that of Nipponbare and 6.27% higher than that of tetraploid parents.The above results provide basis and basic breeding materials for the utilization of tetraploid rice and the establishment of new rice breeding methods.