Fine Mapping Of The Gene Conferring Few-tillers In Wheat Mutant Je0158

Tillering is one of basic components for high yield of wheat,and an appropriate number of tillers can improve the utilization of nutrients and photosynthesis.Tillering is simultaneously affected by genetic and environmental factors.There are many reports on tiller regulation genes in rice and other crops,but relative few in wheat.The few-tillering wheat mutant je0158 obtained by EMS mutagenesis in our laboratory was used to finely map mutant gene through whole genome sequencing and KASP approaches.The main findings are as follows:1.Phenotype of few-tillering wheat mutant je0158.Analysis of main agronomic traits of wild type and mutant je0158 showed that the number of effective tillers of mutant je0158 was no more than 3,which average number was less than 9 in the wild type.Its plant height was significantly reduced by30.1 cm,the thousand grain weight was increased by 6.3 g,while there was no significant change in spike length.2.The mutant phenotype was controlled by a single semidominant gene.The number of tillers≤3 is defined as few tillers phenotype,and the number of tillers>3 is multiple tillers phenotype.In the F₁population constructed by the mutant je0158 and the wild type reciprocal cross showed multiple tillers,and in the F₂ population,but the number of tillers in F₁ is between the two parents,therefore the mutation was controlled by a single semidominant gene.The ratio of individuals with multiple tillers and those with few tillers was 3:1 according to their segregation.3.The target gene was located on wheat chromosomes 1B or 2B.After filtering,the sequenced data was analyzed through the correlation analysis of ED value and SNP-index method,and intervals about600 Mb on chromosome 1B and 1 Mb on 2B were considered to be candidate loci.4.The mutant gene located on wheat chromosome 1B.A total of 21 KASP markers and 1sequencing marker were developed,and through the genotyping analysis of the recombinant plants,the target gene was finally mapped to the 1.7 Mb interval on chromosome 1B.The results could bring new insights into the genetic basis of wheat tiller formation,and provide a theoretical basis for further revealing the molecular mechanism of wheat yield formation.