Study On The Fruit Quality Difference Between Root Tillering And Grafting Propagation Of Lingwuchangzao Jujube

Zizyphus jujube mill cv.’Lingwuchangzao’ is an excellent fresh jujube variety with local characteristics in Lingwu area of Ningxia,which is propagated and cultivated by means of root tillering and grafting.In production practice,it is found that there are differences in the fruit taste of Lingwuchangzao jujube with two propagation methods,but there are few reports on the mechanism of the differences.In this study,the root tillered Lingwuchangzao fruits in white ripening period（NB）,coloring period（NZ）,mature period（NC）,and the grafted fruits in white ripening period（JB）,coloring period（JZ）,mature period（JC）were used as experimental materials,then,the contents of soluble solids,soluble sugars,flavonoids and total acids in different periods of fruit development was determined.And,using high-throughput sequencing technology to sequence the fruit transcriptome,screen the differential genes related to the fruit quality difference between root tillers and grafted Lingwuchangzao jujube,and preliminarily explore the difference of fruit nutritional quality and gene expression between root tillers and grafted Lingwuchangzao jujube,so as to provide basic research reference for the follow-up investigation of the regulation mechanism of fruit quality difference between the two propagation methods,and provide theoretical basis and scientific guidance for improving fruit quality,scientific evaluation and rational selection of propagation methods.The main results are as follows.1.Compared with the fruit quality of root tiller and grafted Lingwuchangzao jujube in different periods of fruit development,the content of soluble solid and soluble sugar were gradually increased,and that content of soluble solid in white ripening period,coloring period and mature period of the root-tillering propagation fruit were alway higher than that of the grafted propagation fruit by 5.7%,11.86%and 19.87%,respectively,with significant differences in each period.The soluble sugar content of root tiller propagated fruit is lower than that of grafting propagated fruit by 27.41%.Soluble sugar accumulated in coloring period and mature period,and the content was 37.5%and 25.27%higher than that of grafted fruits,respectively,with significant differences in each period.The content of flavonoids in the fruits of root tiller and grafted propagation decreased continuously during the development period,with the root tiller propagation decreasing by 60.50%and the grafted propagation decreasing by 46.00%.The root tiller was greater than the grafted propagation in the white ripening period,and the root tiller was less than the grafted in the coloring period and mature period.The total acid content in the fruits of root tiller propagation increased first and then decreased,while that in grafting propagation decreased first and then increased.The root tiller content in coloring period was 51.35%higher than that in grafting,and the root tiller content in white ripening period and mature period was 46.15%and 21.62%lower than that in grafting respectively.2.Based on high-throughput RNA-Seq sequencing technology,65,4509 and 1534 differential genes were identified in JB-vs-NB,JZ-vs-NZ and JC-vs-NC through the comparison of high-throughput RNA-Seq sequencing analysis between root tillers and grafted Lingwuchangzao jujube in different period of fruit development,which were enriched into three categories:biological process,molecular function and cell component through GO function.KEGG pathway annotation significantly enriched the differential genes in secondary metabolite biosynthesis,metabolic pathway,amino acid biosynthesis and other pathways,and the differential genes were significantly enriched in sugar-acid related pathways at mature period.3.The differential genes in five pathways,including starch and sucrose metabolism,galactose metabolism,amino sugar and nucleotide sugar metabolism,glyoxylic acid and dicarboxylic acid metabolism and butyric acid metabolism,which are related to the sugar and acid content in the fruit of Lingwuchangzao jujube during the development of root tillers and grafting propagation were analyzed.Thirty-one differential genes,such as ncbi₁07424266,ncbi₁07414286,ncbi₁07425230 and ncbi₁07429837,were screened out,which were differentially expressed in the sugar and acid metabolic pathways at different periods of fruit development,and regulated the soluble sugar and total acid contents in fruits at different periods.