Fine Mapping Of Fertility Restoring Gene RfK1 In K-Type Thermo-Sensitive Cytoplasmic Male Sterile Wheat Lines And Preliminary Function Predict Of Candidate Genes

In this experiment,wheat thermostable cytoplasmic male sterility line KTP116 A,its isotype maintainer line TP116 B,and restorer line LK783 were used as material.SSR molecular markers,BSR-Seq analysis,and KASP markers were used to positioning cytoplasmic male sterility restore fertility Rfk1 and used comparative genomics to find and develop molecular markers tightly linked to the restorer gene,and to predict candidate gene function based on gene annotation.It provides a theoretical basis for the exploration of the genetic mechanism of wheat K-type sterile lines.The results of the study are as follows:1.Using two test materials KTP116A?LK783,conduct pollen grain observation?K-I2 staining and acetic acid magenta staining?,and scan electron microscopy to observe the anther morphology,inner wall,outer wall,and microspores of the test material at the trinuclear stage.The results show that KTP116 A type of abortion was dyeing failure,and the anthers did not crack;the outer wall was disordered;the microspores of the secondary nucleus were atrophic and deformed.The identification of the microspore fertility of the progeny mapping population revealed that the sterile and fertile strains were close to 1:3 segregation ratio,presumably resulting in two genes that caused microspore abortion.2.The seed setting rate of the BCl population returned from the lines of LK783 and TP116 B of the restorer line and the sterile line KTP116 A were statistically analyzed.The results showed that the sterile line TP116 B was gametophytic infertility;The fertility recovery of the sterile line KTP116 A was controlled by a pair of major effect restorer genes on LK783.Two pairs of reliable molecular markers were found by analysis of the population's SSR markers Xgwm413 and Xbarc137 at a genetic distance of 1.5 cM and 2.1cM.Rfk1 was also located between xwm 413 and xwm 264,with genetic distances of 1.5 cm and 5.7 cm,respectively,according to the results of the study?Liu Baoshen et al.2006?3.Through the BSR-Seq analysis of the mapping population,the relevant SNP markers were obtained and the KASP genotyping was performed on the mapping population.Fine mapping of Rfk1 was performed.Eight pairs of reliable KASP markers were obtained,and Rfk1 is located in the 10 B region between the marked G29121341 A and A40269228 G.These markers are then sequentially mapped onto the SNP index physical map,ultimately positioning Rfk1 within a 10 MB interval between markers G29132341 A and A40269228 G.4.The KASP Mark A was developed by typing the KASP markers on the genotyping of 118 restorers,13 male sterile lines,and 139 backcross populations.According to the gene annotation information on the Ensembl Plants website,the function of the candidate SNP gene was predicted and a total of two annotated candidate genesTraes₁BS_D837C1ADC and Traes₁BS₅1DD23078 were found.