Analysis Of Fruit Quality And Related Gene Expression Of Peach Fruit Treated With Abscisic Acid

Peach(Prunus persica)is a deciduous fruit tree belonging to the genus Prunus in the rose family.It is one of the most important economic fruit crops in the world.China is the largest producer and consumer of peach and nectarine in the world,accounting for more than 50% of the global total.Peach has a long history of cultivation in our country,because of its full fruit,delicious taste,rich nutrition,popular among consumers.Nectarine is a variety of peach,smooth and hairless surface,easy to eat,highly sought after.The quality of fresh peach is mainly determined by its appearance and inner quality.During fruit ripening,color,aroma and taste change significantly,and the conversion of sugars and organic acids is one of the main characteristics of fruit ripening.In order to investigate the effect of exogenous abscisic acid(ABA)on fruit quality of peach,the 5-year old offspring of ’Yingshuanghong’ × ’honey blaze’ and’Qingqing’ × ’Pingdingpantao’ hybrid population were used as test material to study the effect of ABA application on fruit quality of peach.Fruit quality and gene expression were measured regularly.The results show that:1.Pubescent hairs on the surface of common peach have no branches and no glands.Nectarine without pubescent surface.In addition to the smooth outer skin phenotype,nectarine fruit is characterized by displaying a glossy outer skin with wax crystals attached to the cuticle of the peach fruit,forming an irregular rough surface.Peach and nectarine differ in the accumulation of pubescence and cuticle wax on the fruit surface.2.In the initial ripening stage,the single fruit weight of ordinary peach and nectarine was increased continuously,and the single fruit weight of ABA treated fruit was higher than that of the control group;The single fruit weight of ordinary peach is higher than nectarine.3.Compared with the control,ABA can promote fruit coloring.The content of anthocyanins in ABA treatment was higher than that in water treatment.Compared with the control group,carotenoid content increased significantly after ABA treatment.ABA treatment promoted chlorophyll degradation and increased fruit coloring area.4.The quality of ordinary peach and nectarine is mainly determined by the content of sugar and acid.The main sugar is sucrose,followed by reducing sugar,and sorbitol is relatively small.ABA treatment significantly increased the sugar content.After ABA treatment,glucose content changed the most,followed by fructose and sorbitol,sucrose content changed the least.Compared with CK,after ABA treatment,malic acid content of peach and nectarine decreased by 32.2% and 30.2%,citric acid content by50% and 46.7%,pyruvate by 40.2% and 26.6%,respectively.Therefore,spraying exogenous abexic acid could improve fruit sugar content and reduce acid content to affect fruit quality.5.Exogenous ABA treatment can cause the increase of endogenous ABA in plants.Most of the stomata were closed or semi-closed after ABA treatment,but there was no change in stomata after water treatment.6.ABA treatment will increase the thickness of peach peel,ABA treatment makes the epidermal cell layer number and epidermal layer thickness of the peel increase,and the cells are very small,flat type,neatly arranged close.7.After ABA treatment,Fruit sugar transport and metabolic pathway genes Prupe.3G223300,Prupe.8G100100,Prupe.1G434500,Prupe.1G477000,Prupe.1G274700,Prupe.1G319200,Prupe.1G155300,Prupe.1G435600 the up-regulated expression of upe.1G435600 suggested that exogenous ABA affected the expression of sugar transport and sucrose metabolism-related genes,and ultimately affected the accumulation of sugar in fruit.