Inheritance And QTL Mapping For Fruit Size In Sweet Cherry

Sweet cherry?Prunus avium L.?belongs to the genus cerasus avium in the family Rosaceae.It is one of the tree species with the earliest mature fruit in the northern deciduous fruit.Its fruit size is one of the important indexes of the appearance quality and the yield of sweet cherry,is also the primary selection index of sweet cherry breeding.The inheritance of fruit size and other related traits not only provides a theoretical basis for the scientific selection of sweet cherry hybrid parents,but also,the construction of high density genetic map of sweet cherry and the QTL location of fruit size traits provide a basis for the selection of genes for molecular markers assisted selection of fruit size traits and identification of related traits.In this study,the hybrid F₁ population from‘Wanhongzhu'בLapins'was used as a test material to investigate the fruit weight,fruit cells size and the number of fruit cells in 2014and 2015.The genetic analysis of the characters was carried out,and the molecular genetic map of sweet cherry was constructed and the fruit weight,cell volume,cell number and other traits were used for QTL?quantitative trait locus?mapping.The results were as follows:1.The data of fruit weight,fruit cell volume and number of fruit cells in 2014 and 2015were analied Two-year results showed that,fruit weight of sweet cherrywas positively correlated with the fruit cell volume?r=0.185;r=0.24?;and the fruit weight of sweet cherrywas positively correlated with the number of cells?r=0.453;r=0.546?,The correlation coefficient of number of cells and fruit weight is larger than that of fruit weight and cell volume,indicating that fruit weight depends mainly on the number of fruit cells.2.The data of fruit weight,cell volume and number of fruit cells in 2014 and 2015showed a normal distribution with a single peak,indicating that the fruit weight,cell volume and number of fruit cellswere quantitative traits controlled by multiple genes.3.The broad heritability of the size of fruit cells in 2014 and 2015 were 81.7%and95.9%respectively,the broad heritability of the number of fruit cells in 2014 and 2015 was87.5%and 93.1%respectively,indicating that the environmental effect of 2014 was larger than that of 2015.4.DNA samples from 100 F₁ genetic populations of sweet cherry were sequenced by high flux sequencing.1,4634 SLAF markers were obtained.Joinmap 4.0 was used to construct the core frame map of sweet cherry,forming 8 chain groups?F1-F8?with a total length of 849cM,including 718 markers with the average marker density at 1.18 cM.5.QTL analysis of continuous data in 2014 and 2015 was carried out with SLAF genetic linkage map of sweet cherry.Under the total gene threshold of LOD?3.0,95 QTL of fruit weight,fruit cell number and fruit cell volume were detected,and related to fruit weight in2014 covered the 3 QTL detected in 2015,indicating that the QTL of the fruit weight was stable between the years;the number of cells and the size of the fruit covered 17 common QTL,but the size of the fruit,the number of cells and the size of the cells did not covere the same QTL.In the QTL?LOD?3.5?with large genetic effect,36 QTL were obtained for fruit weight,cell volume and cell number,of which,the number of fruit cells in 2014 and 2015were 15 loci and 4 loci respectively.In 2014,the size of fruit cells was detected at 1 locus,while no loci were detected in 2015.In 2014,fruit weight was detected at 5 loci,and 11 loci were detected in 2015.6.Genetic prediction of QTL?LOD?3.5?with large genetic effects revealed that 10candidate genes related to fruit weight were obtained,locating on LG1,LG2,LG6 and LG8 respectively.