Molecular mapping of two novel frost resistance genes in common wheat by 660k SNP array

Abstract

Abstract Low temperature freezing injury has always been one of the natural factors leading to serious yield reduction of wheat. How to improve the frost resistance of wheat has always been the focus of breeders and geneticists. However, the genetic improvement of wheat frost resistance has been slow, mainly due to the fact that frost resistance is a complex quantitative trait, and field phenotypic identification is relatively difficult. Therefore, the discovery of wheat frost resistance genes and the mapping and cloning of frost resistance genes not only provide a theoretical basis for the genetic improvement of wheat frost resistance, but also help to analyze the molecular mechanism of wheat frost resistance. In this study, the wheat line H261 and its EMS mutants LF2099 and XiNong 239 were used as materials. Frost-resistance / non frost-resistance trait segregation was found in the F2 generation of the mutant LF2099 and XiNong 239, and the separation ratio was 15:1. Genetic analysis showed that the frost resistance of wheat was controlled by two dominant overlapping genes, temporarily named Fr-3 and Fr-4. BSA combined with SNP array was used to locate the frost resistance gene. Fr-3 was located between SSR marker BU100519 and KASP marker AX-94843669. The genetic distance between markers was 1.32 cM, and the corresponding physical interval on Chinese Spring 2B chromosome was 5.41 Mb, including 67 genes with functional annotation. Fr-4 was located between the KASP marker AX-94657955 and the SSR marker LC-23. The genetic distance between the markers was 1.79 cM, and the corresponding physical interval on the Chinese Spring 2D chromosome was 2.35 Mb, containing 66 functional annotation genes. Compared with previous studies, Fr-3 and Fr-4 were two new frost resistance genes, which laid the foundation for the fine mapping and cloning of Fr-3 and Fr-4.