Effects Of Gibberellin On Main Physiological And Biochemical Indexes And Anatomical Structure Of 'Red Light' Sweet Cherry Fruit

In this experiment,10a's‘Red Light'sweet cherry?Prunus avium L.?was used as the research material.GA₃ was sprayed on the whole tree at the initial flowering stage and one week after flowering.Five concentrations were set:20 mg/L,40 mg/L,60 mg/L,80mg/L and 100 mg/L,and the treatment with water spray was used as a control?CK?.The effects of GA₃ treatment on physiological and biochemical indexes and structural changes during the growth and development of sweet cherry fruit were studied,which provided reference for production practice and guided practice.Research indicates:?1?Different concentrations of GA₃ treatment had no significant effect on the transverse diameter of sweet cherry fruit.60 mg/L GA₃ increased the growth of longitudinal diameter and single fruit weight;the hardness of each treated fruit decreased compared with the control,and with the concentration of GA₃ Elevated,the lower the hardness;the soluble sugar,soluble solids and V_C content of GA₃ treated sweet cherry fruit were significantly lower than the control,but the titratable acid content increased significantly,and the intrinsic quality of the fruit deteriorated to some extent.Minimize the use of GA₃,especially at high concentrations.?2?The relative conductivity and MDA content of sweet cherry fruits treated with GA₃ increased with the increase of concentration,and entered the senescence softening period in advance;the PPO,POD,CAT and SOD activities of the control showed high.At each GA₃ treatment,the higher the concentration,the smaller the antioxidant enzyme activity,and the higher GA₃ concentration accelerated the ripening and aging process of sweet cherry fruit,but failed to accelerate the quality formation process.?3?PG,?-Gal,?-Glu and PME existed in the whole growth and development of sweet cherry fruit,which were closely related to the hardness of flesh,showing a significant negative correlation;GA₃ treatment made the activity of four cell wall hydrolase activities compared with the control.The increase,thereby promoting the softening of the sweet cherry fruit,and the higher the concentration of the GA₃ treatment,the faster the fruit softening speed,especially the 100 mg/L treatment enzyme activity is high.During the development of sweet cherry fruit,?-Glu and?-Gal are the main hydrolase,which has a great relationship with the later softening.?4?Anatomical structure It was observed that different concentrations of GA₃treatment had different effects on stratum corneum thickness,pulp cell size,epidermal cell thickness and size.Correlation analysis showed that fruit firmness was positively correlated with stratum corneum thickness and fruit epidermal thickness.However,it was negatively correlated with cell size and epidermal cell size.?5?Ultrastructural observation The cell wall of the control sweet cherry fruit was significantly thicker,tighter and more uniform than the GA₃ treated cell wall in all three periods.Sweet cherry fruits that were not treated with GA₃ had a relatively long cell wall integrity and cell regional integrity.In connection with cytohydrolase activity and hardness,it is known that GA₃-induced increase in cytohydrolase activity is an important cause of this phenomenon,resulting in a decrease in hardness.