Vernalization Gene Composition In China And Novel Allele Variations Of The Vrn-D1c

In order toreveal the developmental characteristics of varieties and clarify the dominant-recessive composition and distribution of vernalization genes in China wheat varieties,the study based on the previous studies analyses the dominant-recessive composition of VRN1 and VRN3,hoping to provide a theoretical basis for further molecular improvement of wheat developmental characteristic.In order tostudy the consistency of genotype and phenotype,the variability of 200 domestic wheat varieties in Vrn-D1 promoter region were detected on the basis of analyzing the vernalization gene VRN1 and VRN3.In this study,in order to get a well comprehensive understanding of the VRN2 fanction,the mechanism of the vernalization geneVRN2 in common wheat as well as the shoot tips of wheat genetic transformation system,at the same time,this study used the common winter wheat JING841 as the RNA interference of VRN2 research materials with the expression vector pFGC5941.The main findings are as follows:1.Detecting the vernalization genotype of 200 domestic wheat varieties,the result showed that no dominant allele of Vrn-Al or Vrn-B3 was found in the wheat cultivars in this study.The dominant Vrn-Bland Vrn-Dl proportion were 8.5%and 40.5%.There were 54 germplasms for the Vrn-Dla type(66.7%)and 27Vrn-Dlb(33.3%)type in the 81 dominant cultivars.2.Among 119 materials which were identified recessive by detecting 200 varieties with the Vrn-Dl single nucleotide mutation primer in the promoter region,4 materials have insertion mutation in VRN-D1 promoter region.By sequencing analysis,these mutations have same length and position,which indicates that this insertion mutation is conservative in wheat.In this study it was named Vrn-Dlc.This is alsothe first time to find insertion mutation in the promoter region of VRN-D1,and the rest 115 were indentifiedas the recessive vrn-D1 materials.3.In the 81 detected Vrn-D1cultivars,there were 54 germplasms for the Vrn-D1a type with6materalscontain Vrn-B1 and Vrn-D1a,the other 48 cultivars'phenotypic were weak-spring with the consistency between the phenotypic data and genotype 83.3%while the consistency was 88.0%between the phenotypic data and genotype in the 27 Vrn-D1b cultivars which had 2 materals containing Vrn-B1 and Vrn-D1b.Therefore using this molecular marker to detect the phenotypic traits of weak-spring and facultative have high accuracy.4.The results showed that when not considering the single nucleotide mutation in the promoter of Vrn-D1,the consistency was 27.5%between the phenotypic data and genotype while the consistency was 56.6%when considering it,so the studies suggest that Vrn-D1a and Vrn-D1bwerean effective molecular marker for weak spring and facultative wheat in huang-huai region.5.Among all the winter varieties,not all of the vernalization genes are recessive;while varieties of recessive vernalization genes are not all winter performance,with weak spring varieties and facultative varieties existing.The facultative varieties account for 62.6%,which is the largest proportion of survey.Among the genotype detection of 166 cultivars,57 varieties(34.3%)are recessive in all vernalization loci,while field survey shows they are sydsporfacultative.These results showed that there are still other genetic or environmental factors affecting the characteristic of wheat vernalization.6.A transformation vector of VRN2 were constructed by Agrobacterium-mediated wheat stem-tip cutting method and transferred into common winter wheat variety JING841.After T1 generation glufosinate-ammonium and BAR gene PCR screening,80 individuals were initially identified as positive with transformation efficiency of 8%,so the method have an adventage according to its simple process,low cost,short test cycle and high conversion efficiency.Follow-up studies areneeded to identify the transformation efficiency,stability as well as interference effect of VRN2 gene expression.