Evaluation Of Wild Plum Resources In Chongqing And Identification Of MYB Transcription Factors

Plum is a temperate fruit tree of the Rosaceae and Prunus genus,and is one of the most beloved drupe fruits for consumers worldwide.It has a wide variety of varieties,colors,and flavors.Chongqing region is rich in wild plum resources.So far,there have been few comprehensive evaluation studies on wild plum germplasm resources,especially on genetic diversity and population genetic structure,fruit quality,and skin color of wild plum.This has affected the protection of wild plum germplasm resources and the exploration of excellent germplasm resources.This article conducted a comprehensive evaluation and genetic diversity analysis of wild plum germplasm resources in Chongqing region.Through molecular biology and physiological analysis methods,the evaluation and analysis of wild plum were mainly conducted from three aspects: genetic diversity,fruit quality,and gene expression levels related to fruit skin color,in order to provide theoretical basis for the protection and development of wild plum germplasm resources.The main research findings are as follows:1.A total of 208 bands were amplified using 18 primers,of which 200 were polymorphic bands,with a polymorphic band ratio of 96.15%.Among the 18 primers,the amplified bands ranged from 7 to 16,and UBC835 had the highest identification efficiency,effectively identifying 67 wild plum germplasm resources.Combined with UBC811,UBC873,UBC844,UBC815,and UBC845,150 wild plum germplasm resources could be completely distinguished,and a DNA fingerprint map of 150 resources was constructed based on this.The genetic similarity coefficient of 150 plum germplasm resources ranged from 0.571 to 0.963.A cluster map was constructed based on the genetic similarity coefficient,and the 150 samples were divided into 3 categories with a genetic similarity threshold of 0.712.By analyzing the genetic diversity of wild plum individuals,the percentage of polymorphic loci(PPB),Nei’s gene diversity(H),and Shannon information index(I)at the individual level of the tested plum germplasm resources were 96.15%,0.3052,and 0.4634,respectively,which were higher than the corresponding index of the population,indicating that the genetic diversity at the individual level was higher than that at the population level.The analysis of genetic diversity among different populations shows that the genetic diversity level in Wuxi region is the highest,followed by the Nanchuan population,and the Dagan population is the lowest.Analyzing the four subpopulations in the Wuxi region,it was found that the genetic diversity level of Jinjia Village was higher than that of Hongchiba.2.Through correlation analysis,principal component analysis(PCA),and cluster analysis,a comprehensive evaluation was conducted on 19 wild plum fruit quality indicators.Five principal components were obtained,including weight factor,flavor factor,color factor,sweetness factor,and functional factor.Each factor was renamed after rotating the load square,with low correlation and low overlap rate.The evaluation was conducted from four aspects: weight,color,flavor,and function,and the high-quality wild plum fruit Lianhua-4 with large fruit size,high sugar to acid ratio and solid to acid ratio,and good flavor was selected.3.Through full target anthocyanin determination and analysis,a total of 37 anthocyanins were identified in 4 wild plums with different peel colors.Hierarchical clustering analysis of total samples and total anthocyanins showed that the biological repeated samples were clustered into a bunch respectively,and the differences of different anthocyanins in the wild plum peel were obvious.According to research diagram,cyanidin 3-O-galactoside,cyanidin 3-O-xyloside,delphinidin 3-O-arabinoside,and gesnerin are the unique anthocyanins in the wild red plum,and cyanidin 3-O-robino bisoside,delphinidin 3-lathyroside,delphinidin 3-rutinoside-5-glucoside are the unique anthocyanins in the wild yellow plum.4.The MYB gene family of plums was analyzed by molecular biology,and the repetitive sequences were removed by manual inspection,and verified in NCBI and SMART databases.Finally,244 protein sequences containing MYB domains were obtained.Then,the phylogenetic tree analysis was carried out with the identified anthocyanin structure promoting or inhibiting gene R2R3-MYB of fruit trees,and 29 genes possibly related to anthocyanin regulation were obtained,Quantitative analysis of 29 candidate genes was conducted through qRT PCR,and four genes that may regulate anthocyanin accumulation in wild plum fruit peel were screened.