Development Of Molecular Fingerprints Based On Retrotransposon And Applications In Rice Breeding

The utility of heterosis is an effieient way to improve yield in rice.At present, the current result of the selection of hybrid parents are the close kinship so the production of new varieties bred have no major breakthrough in yield.The molecular marker assisted breeding is an effieient way for making full use of genetic diversity,fine seletion at molecular level,which leads develop rice hybrids for rice production and peaple's demands. In this study, species identification and prediction of heterosis about three groups of rice by retrotransposon-based molecular marker techniques. The results were as follows:1.Subspecies differences in DNA sequences between Indica and japonicaA total of 173 bands were amplified by 6 primers in the PCR analysis with 12 indica and japonica, of which 97 are polymorphic, polymorphism level is 56.1%; Polymorphism of indica rice 32.1%, higher than the polymorphism of japonica rice(24.3%). Based on the genetic distance clustering can be clearly divided into two categories-Indica and Japonica,and the Indica polymorphism higher than the japonica rice. This shows that the use of retrotransposon-based molecular markers can accurately identify subspecies and varieties of genetic differences between the Indica and Japonica.2. Prediction of Heterosis in RiceThe eight rice parents( in which four female parents and four paternal), as well as their 12 hybrids can be well distinguished from rice materials with 5 pairs of primers of molecular fingerprinting datas. Using UPGMA method gets the dendrogram which based on the genetic distance.Analyse the correlation analysis between genetic distance and yield of agronomic traits. Agronomic traits of hybrid performance and parental combining ability analysis showed that among the vast majority of traits general combining ability variance is greater than specific combining ability variance. Therefore,the genetic effects get first place to the additive genetic effects in hybrid combinations of each trait.In the combination of ultra-high-parent heterosis, one parent have a high general combining ability, at least. The genetic factors that explain relatively large impact on the sub-representative type. Simple linear regressio relationship between genetic distance and various agronomic traits show that most of them are positive correlation. However, the coefficient of determination is not high.3. Identification of partial indica-japonica rice sideThe average polymorphism is 56.5% for 53 kinds of partial indica-japonica rice side with 5 pairs of primers show that there is a great genetic diversity between the partial indica and japonica side. Cluster analysis showed that partial indica and japonica is divided into two categories obviously. And by the same parents of the hybrids in this group with closer genetic relationship. These results suggest that the use of retrotransposon-based molecular fingerprints can distinguish not only the partial indica-japonica materials'differences and can show the genetic characteristics of these rice materials.