Construction Of Wheat EMS Mutant Library And Identification Of Functional Genes

The construction and analysis of mutants is an important research content of functional genomics,which provides direct tool materials for gene function analysis.It is one of the most direct and effective methods to isolate and identify gene function by constructing saturated gene mutation population.Fhb7 gene of Thinopyrum elongatum is an excellent source of resistance to scab in wheat.The functional analysis of Fhb7 gene will be helpful for the effective utilization of Fhb7 gene in wheat breeding for resistance to scab.However,Fhb7 gene is linked with genes related to yellow pigment synthesis,which makes the yellow pigment content of wheat flour high and has certain restrictions on the wide application of Fhb7 gene.In this study,the heterozygous Fhb7 wheat Thinopyrum elongatum was mutated with the solution of chemical mutagen ethyl methane sulfonate(EMS).The mutant library of heterozygous Fhb7 wheat Thinopyrum elongatum was constructed,and the tilling of Fhb7 gene was detected,and some mutants related to flour color were screened.The main results are as follows:1.The background material of Jimai 22 with Fhb7 short fragment translocation line was treated with EMS solution of 0.8% concentration.7309 single panicles were harvested in M1 Generation,and 4473 M2 single plant populations were obtained by single grain transmission.2.DNA was extracted from about 4000 individual plants of M2 generation,and the target gene Fhb7 was tilling screened,and the full-length PCR product of Fhb7 was directly sequenced.The homozygosity and heterozygosity of each point mutation were verified by DNAMAN software,and 43 mutants were finally screened.3.Through the inoculation and identification of scab resistance with leaves in vitro,5 missense mutations and 2 termination mutations were found in the 7 Fhb7 gene mutants which were significantly different from the resistant control(translocation line receptor material);although there were some differences in the susceptibility of the 7 mutants,the disease spot area was significantly larger than that of the resistant control.From the phenotypic results of scab resistance,these seven mutations may be the key amino acids or domains that determine the function of protein.4.According to the color of grain and flour,645 strains of M3 generation were obtained.The mutant lines with good resistance to scab and high whiteness of flour were obtained,which is beneficial to the effective application of Fhb7 gene in wheat breeding for scab resistance.5.The protein encoded by the Psy Gene of Thinopyrum elongatum is mainly different from that of common wheat in amino terminus.At present,the genetic transformation vector of the Psy Gene of Thinopyrum elongatum,which is controlled by its own promoter,has been constructed,which lays a foundation for studying the effect of the gene on the content of yellow pigment in flour.