Cloning And Genetic Effect Analysis Of TaGW2L,a Gene Associated With Kernel Weight In Wheat

Wheat is a major food staple in mang parts of the world.China is the largest wheat producer and consumer in the world,and the production of wheat are important for our country's food security.In current national conditions,higher yield breeding is the fundamental way to enhance wheat total production level in China.Thousand grain weight is one of the key compenents,and it is mainly determined by grain length(GL),grain width(GW)and grain thickness(GT).The grain weight of wheat is directly correlation with yield.The grain weight and the sustained improvement of grain yield are main targets of wheat breeding.Identifying genes and developing functional markers associated with grain weight using molecular biology to find favored allele play an important role during appplication and guideline of modern wheat breeding.In this study,TaGW2 which controls wheat grain width,grain weight and grain filling rate,has a positive effect.The homologous gene TaGW2L was cloned and studied in wheat,and its molecular characteristics and genetic effects were analyzed.This study found that TaGW2L has similar molecular properties to TaGW2,and its subcellular localization and spatiotemporal expression characteristics are consistent and may have similar biological functions.By cloning the genomic and cDNA sequences of TaGW2L,the gene was found to be located in the seventh homologous group of wheat,consisting of 8 exons and 7 introns,encoding a protein of 417 amino acids,which has a zinc finger structure of the RING type.Domain,with the function of E3 ubiquitin ligase.GW2L and GW2 are widely present in monocotyledonous and dicotyledonous plants.Phylogenetic tree analysis indicated that GW2L and GW2 belong to different members of the same gene family and existed before the differentiation of monocotyledonous and dicotyledonous plants.The homology between GW2L and GW2 and similar molecular properties suggest that it may also play a role in regulating grain weight and seed size.This study further analyzed the genetic effects of TaGW2L.The polymorphic sites of TaGW2L-7A were found by sequencing 34 wheat micro-core germplasm materials with high diversity,and they were divided into three closely linked haplotypes,namely Hapl,Hap? and Hap?.The three haplotypes were successfully distinguished by developing two molecular markers,and 157 landraces and 348 modern cultivars in wheat micro-core germplasm were scanned,and genotype data and phenotypic data were correlated and found to be It is an excellent haplotype with a high 1000-grain weight,which can increase 1000-grain weight 1-3 g in modem breeds.From the evolution of landraces to modern cultivars in China,it can be seen that the excellent haplotype Hap? is strongly positively selected by the artificial,and its frequency gradually increases with the advancement of breeding years.In addition,it was found that there is an additive effect between the haplotypes of TaGW2L-7A and TaGW2-6B.Although the effect of TaGW2L-7A is weaker than that of TaGW2-6B,the excellent haplotype combination of the two can further increase the 1000-grain weight.At the same time,transgenic research on TaGW2L and TaGW2 in wheat was carried out.Positive transgenic plants have been obtained,and subsequent phenotypic analysis is still in progress.In conclusion,this study cloned a TaGW2 homologue,TaGW2L,which confirmed that TaGW2L is similar to and has a genetic effect on 1000-grain weight.Two functional markers developed can be used in Marker assisted selection(MAS)breeding.Other yield trait related markers have certain application potential in modern wheat production.