Mapping Of Distichous Alternate Phyllotaxis Gene In A Novel Germplasm Wanzhonghuang 601

The phyllotaxis arrangement on stem effects the position of leaf and canopy structure in soybean.In general,the phyllotaxis of cultivated soybean(Glycine max)are alternate,which is the main component of soybean plant type.In the early stage,a distichous phyllotaxi novel germplasm wanzhonghuang 601 was obtained by chemical mutation of Zhongpin 661 with high yield and disease resistance by EMS.Using this mutant in combination with the Zhonghuang 13 configuration.The distichous alternate studies were used to provide reference for genetic improvement of soybean plant type.The results showed that:1.Compared with the wild type Zhongpin661,the leaf order of the novel germplasm Wanzhonghuang 601 changed significantly,the leaf on the stem changed from a decussate alternate to a distichous alternate arrangement,that is,alternately compound leaves are arranged in a plane type.The branches of the multi-branched plants from the progenies of Zhonghuang 13 also showed the characteristics of plane arrangement.2.The content of CTK in SAM and leaf segment of two phenotypes was determined.The results showed that the content of CTK in SAM and leaf segment of distichous phyllotaxis soybean was significantly higher than that of alternate phyllotaxis soybean,the CTK content of SAM in distichous phyllotaxis soybean was lower than leaf segment,but it was opposite in alternate phyllotaxis soybean,which indicated that the phenotype might be caused by the difference of CTK content.3.Moreover,the pools were constructed by using F5 interactive and distichous alternate traits,respectively,and the mapping was performed by BSA-seq.According to the SNPindex and In Del-index method association analysis,four regions were mapped on chromosomes 14,15,containing a total of 216 genes.4.The results of qRT-PCR analysis showed that the relative expression patterns of Glyma.15G003200,Glyma.15G014200,Glyma.15G006100 and Glyma.15G010400 were highly expressed in the diallel alternate apical meristem,which might be a candidate gene for this trait.Among them,Glyma.15G003200 responded to cytokinin,Glyma.15G014200 and Glyma.15G006100 responded to auxin.The above results provide a reference and theoretical basis for mechanism analysis of the formation of distichous alternate characters in soybean and the utilization of the novel germplasm in breeding.