QTL Mapping Of Drought-resistant Traits Based On SNP Of Wild Jujube(Zizyphus Jujuba Mill.var.spinosa) In Ningxia

Wild jujube(Zizyphus jujuba Mill.var.spinosa)are light-loving,drought-tolerant,barren-tolerant,easy to survive,and has good ecological adaptability.However,due to the lack of understanding of wild jujube,the protection,development and utilization of wild jujube germplasm resources are insufficient.In this paper,the genetic diversity and correlation of 9 drought resistance traits of wild Jujube were studied by taking 150 leaves from 5 wild Jujube populations in Ningxia as experimental materials.These QTLS related to drought resistance traits of wild Jujube in Ningxia were mapped using GWAS.The results provided a theoretical basis for the development of wild jujube germplasm resources in Ningxia.The results are as follows.(1)Statistical analysis and genetic diversity analysis of 9 drought-resistant traits of wild jujube in Ningxiashowed that the values of 9 traits were normal and skewed distribution,the coefficient of variation ranged from 14.76%～62.17%,the genetic diversity index ranged from 1.55～2.06,and the generalized heritability ranged from 0.835～0.990.There was a certain correlation among 9 traits.(2)The genetic structure analysis showed that when K=9,150 jujube trees can be divided into 5 groups and 9 subgroups,the first and third subgroups were all from LW,the second subgroup were from ZW,the fourth and fifth subgroups were from HLS,and the sixth and seventh subgroups were from ZN,In the ninth subgroup,one wild jujube was from ZW and the eighth and the rest of ninth subgroups were from WZ.(3)By GWAS analysis,a total of 12 QTLs loci with 162 genes associated with drought resistance in Ningxia wild jujube leaves were localized.12 QTL loci were located on Chr.1,Chr.2,Chr.6,Chr.8,Chr.12 and Scaffold790,and the phenotypic interpretation rates of these QTL loci were 20.743%～50.365%.There were 2 QTLs qMDA1-140 73 1 70 and qMDA1-14278147 associated with malondialdehyde content on Chr.l with phenotypic interpretation rates of 28.826%and 24.920%,respectively,and 1 QTL qPRO23598885 associated with proline content on Chr.2 with a phenotypic interpretation rate of 42.204%,and 3 QTLs loci related to chlorophyll on Chr.6,qCHL6-1529704,qCHL6-1529745,and qCHL6-1548799,with phenotypic interpretation rates of 21.222%,21.222%,and 20.743%,respectively;1 QTL and 2 QTLs related to leaf thon length and MDA content on Chr.8,qLTL8-12185053,qMDA8-19635461 and qMDA819686893,with phenotypic interpretation rates of 26.965%,25.517%and 27.635%,respectively;on Chr.12,there were 2 QTLs associated with SOD activity,qSOD12-17851535 and qSOD12-17851881 with 48.335%and 50.365%of phenotypic interpretation,respectively;and 1 QTL qRELS790-71987 on Scaffold 790 associated with cell membrane permeability,with 26.539%of phenotypic interpretation.(4)Through the GO function annotation of genes,5 key genes may be related to drought resistance traits of wild jujube in Ningxia,which were ZjMYB44,ZjUCLOC107419974,ZjDnaJ50,ZjUCHL22 and ZjHSTFB-2b,ZjDnaJ50 has 1 signal peptide and 2 transmembrane regions,while other genes have no signal peptide and transmembrane region.There were some differences in the expression levels of the 5 genes in the 5 wild jujube populations.