Construction Of Double Haploid Populations Derived From Kongyu 131 And Daohuaxiang 2 And Genetic Analysis Of Rice Quality

Kongyu 131 is the major cultivated rice variety in Heilongjiang Province.It is loved by the people because of moderate maturity,cold-resistant,high yield,strong resistance and other features,which has been spread for about 20 years in Heilongjiang Province.Daohuaxiang 2 is the major feature in Wuchang City due to excellent eating quality.With economic development,the rice quality especially cooking and eating quality has been increasingly demanding by people.Through analyzing reasons of the rice quality differences between Kongyu 131 and Daohuaxiang 2,it can lay the foundation at the molecular level for the rice quality improvement of Kongyu 131.The DH(doubled haploid)population from rice anther culture can be used to construct map and map gene;Molecular marker-assisted selection breeding can be directly improved rice varieties.Combining the two kinds of methods to analyze the rice quality differences between Kongyu 131 and Daohuaxiang 2,it can provide not only accurate results rapidly,but also a lot of informations about molecular markers for future studies.This can help to accelerate the process of the rice quality improvement of Kongyu 131.The preliminary work in our lab proved that the eating quality of Daohuaxiang 2 is better than Kongyu 131.In this study,the cooking and eating quality of Kongyu 131 and Daohuaxiang 2 were analyzed to find the differences.17 starch synthesis-related genes,which were based on the research of Tianzhixi in 2009,were sequenced to find the genes causing the rice quality differences between the two varieties.The two appropriate groups DH and BC were chosen to verify the reasons.The test analysis showed that gel consistency is one important reason for the cooking and eating quality differences of two varieties;Sequenced 17 starch synthesis-related genes,only SBE3 and SSII-1 exist sequence differences between Kongyu 131 and Daohuaxiang 2,and the differences are caused by single base.Therefore SBE3 and SSII-1 were guessed that they are the main reasons for the differences of the gel consistency between the two varieties.The gel consistency was analyzed using the exchanged lines in BC1F4 and these lines from DH which contains the SBE3 and SSII-1 genes and more Kongyu 131 background.The results showed that the SBE3 and SSII-1 genes from Daohuaxiang 2 can increase the gel consistency,SBE3 works a lot to enhance the gel consistency but SSII-1 works a little.Finally,the test results showed that SBE3 and SSII-1 especially SBE3 is one of the main reasons why the eating quality of Daohuaxiang 2 is better than Kongyu 131.The constructed DH population has 171 lines,anther induction rate was 10%,green seedling rate is 5.9%,seed setting rate is 71%.The differentiation medium for anther culture were optimized,and the best differentiation medium is the medium which is added with 60mg/L Silicon,0.25mg/L AgNO3 and 0.75mg/L CuSO4·5H2O.The homozygosity and distort segregation about DH groups was analyzed using 38 polymorphic SSR markers,all lines are all homozygous and exhibit normal Mendelian inheritance,which determined that the DH group is suitable for constructing genetic map and gene mapping.About molecular marker-assisted selection,in BC1F2 the SSII-1 exchanged lines in the both sides have been selected,while SBE3 exchanged lines have been selected only in one side.Now BC group has selfcrossed to BC1F4 and backcrossed to BC3F1,basically Kongyu 131 background.