影响糯稻直链淀粉含量的QTL及效应分析.

(Objective) Amylose content is a key trait affecting the quality of glutinous rice. The present paper aimed to analyze the important significance of its genetic basis for rice quality improvement. (Method) In the study, we constructed the BC2F4 and BC2F5 backcross genetic generation populations of Pinnuo R191/Jinguisimiao//Jinguisimiao///Jinguisimiao' in a genetic background carrying the wxwx gene, and used the group segregation analysis method to SNP-type both parents and the high and low pooled populations using the GSR40K rice Gene- Chip, candidate genes affecting amylose content in rice were anchored according to the analysis results. (Result) Two candidate gene segments controlling amylose content were located on chromosome 5 from 0.04 to 0.37 Mb and chromosome 12 from 17.53 to 24.09 Mb. 14 pairs of polymorphic SSR markers and SNP markers were screened from the candidate intervals of chromosome 12, and the genetic linkage map was constructed by using QTL IciMapping software. By using Inclusive Composite Interval Mapping (ICIM), QTL qAC12 affecting amy- lose content was detected in the interval of N21774-A24633 with an interval distance of 3.46 Mb. The mean contribution rate to amylose content was 14. 10%, and the additive effect value was -0.11. For the analysis of candidate QTL at the end of chromosome 5, based on the genotyping results of the predicted interval marker Zc15_167, combined with the phenotype estimation, the contribution rate of QTL qAC5 to the phenotype of amylose content was 9.83%, and the additive effect value was 0. 156. 【Conlusion】 The amylose content of rice is not only regulated by Wx gene, but also closely related to other QTLs genes. It is of great significance for the breeding of new varieties of high quality rice to excavate and analyze its genetic basis. In the study, the micropotent QTL on chromosome 12 and chromosome 5 affecting amylose content of glutinous rice is identified, which can be helpful for molecular marker-assisted breeding of amylose content of glutinous rice, and has good practical value for reducing amylose content of glutinous rice and improving the quality of glutinous rice. [ABSTRACT FROM AUTHOR]