Mapping And Functional Marker Development Of Recessive Genic Male Sterility Gene Ms1r In Common Wheat

Utilization of wheat heterosis is an important method to increase wheat yield.The seed production of hybrid wheat must rely on male sterile lines.Huang Shousong discovered a new recessive genic male sterile line,and established blue-standard male sterile breeding system.In this study,the male sterility abortion mechanism was studied,and the population constructed by sterile line 15 fan 03 and restorer line mian07-374 was used to map and developt linkage molecular markers of the male sterility gene ms1r.Development of functional markers was performed according to different mutants of Ms1 gene.The main findings are as follows:1.Compared with the restorer line mian 07-374,the sterile line 15 fan 03 was light green after heading stage,the glumes open large angle at flowering stage,the hull was translucent,the anther was thin,empty,and no cracking loose powder,and the anther remained in the glume due to unelongated filament.After the mature pollen was stained by I2-KI,most of the pollen grains were light yellowish brown,and irregular pollen shape indicated poor pollen vigor and loss of fertility.Scanning electron microscopy showed that the inner wall of the anther was smooth and free of granular matter.The pore ring of the pollen germination hole was not obvious,and the hole cover was sunken;the pollen grains of the sterile line were reduced,and collapsed,irregular and deformed.Anther cross-cut paraffin sections showed no signicant developmental differences in microspores and tapetum of the sterile and fertile lines during microspore stage.In the single-core edge period,it can be seen that the degradation of the inferior tapetum layer is delayed,and the content of the sterile pollen in the trinuclear pollen stage is completely degraded,leaving only the germination hole,while the pollen from fertile line has a deeper color indicating its normal vigor.2.Among the 1205 F2 populations,the ratio of fertile plants to sterile plants was3:1,indicated that ms1r male sterility was controlled by single recessive gene.By hybrid separation analysis(BSA)and SSR marker scanning,the target gene was located between SSR markers Ms4BS42 and Ms4BS199 with a genetic distance of 1.4c M,a physical distance of 6.57 Mb,in which Ms4BS53,Ms4BS234,Ms4BS236 were co-segregated with the target gene.An inversion segment with a fragment size of 5.2Mb was predicted during the localization process.3.According to the results of Wheat660 K chip detection,one SNP closed the deletion boundary was found on the upstream of ms1r gene deletion interval.The probe sequence was AX-111474959,the SNP physical position was 10.615 Mb and the development of closely linked CAPS1,CAPS2 and CAPS3 markers.4.In order to increase the molecular markers density in ms1r interval,Wheat660 K chip was used to analyze SNP locus of sterile line,restorer line,sterile mixed pools and fertile mixed pools.The results showed that there were 329 SNP locus in sterile pool between the localization interval of Ms4BS42 and Ms4BS199,of which 138 SNPs were missing.These SNP sites was continuously distributed between10.9 Mb and 15.6 Mb of the wheat 4BS chromosome.The results of FISH further confirmed that there was a chromosomal deletion fragment in the sterile line chromosome 4BS localization interval.The deletion interval was determined between the markers MS19,MS41 and MS371,MS571 by SSR molecular markers scanning,the physical positions were 10.782361 Mb and 10.838408 Mb,14.660622 Mb and15.921461 Mb,respectively.Among them,the physical distance between MS19 and MS41 is 56.047 Kb,and the physical distance between MS371 and MS571 is12680.39 Kb.5.Based on the ms1r gene locational results and the identification of chromosome deletion in localization interval,the ms1r male sterile line may be similar to the Ms1(Traes CS4B02G017900)deletion mutant.Therefore,the sterility gene was named“ms1r”.According to the mutation site of the mutant gene Ms1,molecular markers of four mutants ms1 d.1,ms1 h,ms1m and ms1 p were designed,which are ms1 d.1-1,ms1h-1,ms1m-1 and ms1p-1,respectively.These markers are functional markers of Ms1 gene.