Construction And Grain Quality Analysis Of Introgression Lines For Different Wx Alleles In The Background Of Rice Variety 9311

Rice is one of the main crops in world.In recent decades,rice yields have increased significantly because of the application of hybrid rice.However,the rice quality is very low due to higher amylose content,harder gel consistency and higher degree of chalkiness,etc.In this study,we analyzed the sequence of different Wx alleles,and developed corresponding molecular markers.Using marker-assisted-selection(MAS)and back-crossing breeding,we constructed several introgression lines(ILs)containing different Wx alleles with 9311 as recipient parent to identify the effects of these alleles on rice quality.In addition,we hybrid the ILs with different sterile lines to analyze the influence on hybrid rice amylose content.These results established the foundation of exploration the genetic effects of different Wx alleles,and also provided important materials for improving rice quality of hybrid.The main results are as follows:1?We constructed a serious of ILs with 9311 as the recurrent and Nanjing46,Lemont,Mowanggu,Haopi,Guichao2hao,and Taizhongbeidilhao(TN1)as the donor,which has different Wx alleles.Combing with continuous backcross and MAS,the genetic background and agronomic traits of ILs show similar with 9311,which provide well materials to analyze the genetic effects of different Wx alleles.2?We compared the difference between ILs,which containing four different Wx alleles,for rice AC.The results showed that,IL(Wxin)and IL(Wxsgc)have positive effects on rice AC.Instead,IL(Wxhp)and IL(Wxmq)have low rice AC.These results indicated that different alleles have different effects on rice AC.3?he datas of starch viscosity spectrum(RVA)showed that the peak viscosity,hot paste viscosity and cold viscosity of ILs were significantly higher than those of 9311.Compared with those of the recurrent(9311),Breakdown value of the IL(Wxmq)and IL(Wxin)were higher,Consistence value and Setback value were lower;Breakdown value of the IL(Wxin)and IL(Wxin)were lower,Consistence value and Setback value were higher;Breakdown value and Consistence value of the IL from guichao2hao?zhenshan97B and taizhongbendilhao were lower,Setback value were higher.The correlation analysis indicated that the amylose content of the ILs has a significant negative correlation with the Breakdown value.4?In this study,we used several ILs derived with recipient parent 9311 to hybrid with sterile lines,and measured the grain AC of hybrid F1.We found that Wxhp and Wxmq can reduce the amylose content of hybrid F1 on different levels.The influences of Wxin and Wxsgc on F1 dependent on different combinations.Therefore,WxhP and Wxmq could be further utilized to improve hybrid grain quality.