Evaluation Of Peach Gummosis Disease In Gerplasm And Genetic Analysis Of The Associated Locus

Peach(Prunus persica [L.] Batsch)is one of the economically important stone fruits in the Rosaceae family.It is originated from China.Peach gummosis disease is one of the most destructive disease in South China,which affect the healthy production of the peach industry.Breeding and selection of gummosis resistant varieties are urdently needed.In this study,we collected the data of gummosis severity of 132 peach varieties during 2016-2019,and selected 83 peach varieties with different resistance to implement whole genome re-sequencing.Whole genome SNPs were obtained from genome re-sequencing.Association analysis between genotypic and resistant phenotypic data was performed to identify the associated loci which are related gummosis resistance.Annotated genes were searched through KEGG,GO,COG database.The main results are as follows:(1)Different varieties showed significant differences in the incidence index of gummosis diseasein 7-9 years trees.Among 132 peach varieties,14 varieties belong to the high-resistant varieties with the incidence of gummosis disease ranged from 0-1,such as ’Nan Shan Tian Tao’ and ’Ling Can 2’,while 79 varieties belong to medium-resistant varieties with the incidence of gummosis ranged from 1-3,such as’ Hakuri’,’Kawanakajima Hakuto’.There are 39 low-resistant varieties,of which the incidence is in the range of 3-9,for instance ’Fei Cheng Bai Li’,’Hu You 278’.(2)Three resistance-related loci were identified through BSA grouping and association analysis.The association results of the nectarine group showed that most of the loci are located on chromosomes 1,6,8,among which the mostsignificant loci is Chr01:37,724,273.In the peach group,that most of the loci were located on chromosome 2,and the most significant loci was Chr02: 5,277,199,and the related loci were also detected on chromosome 6.There are no same loci in two groups,but the two groups has common regions,which are Chr01:12,492,448-13,985,099 and Chr06:27,324,924-28,013,384,these regions are close to peach genes encoding Pru p 1 and Pru p 3 allergens respectively.(3)The genotype were calculated in both groups.We found that the genotype of6 high-resistant nectarine varieties is 100% as TT,and the genotype of low-resistant nectarine varieties is 60% as CC in the loci Chr01:37,724,273.The genotype of high-resistance peach varieties are 85% as TT and low-resistance common peach varieties are 100% CC in the loci Chr02: 5,277,199.In loci Chr06:28,013,384,100% of high-resistance varieties had genotypes of GG,and 60% of the low-resistance varieties had genotypes CC,the associated gene at this locus is Prupe.6G312900,which is a protein-encoding gene.