Effects Of GA₃ And CPPU Treatment On Seedlessness And Fruit Quality Of 'Shine Muscat' Grapevine

In this study,4-year-old 'Shine Muscat' trees were selected as material,and the effects of different concentrations of gibberellin(GA3)supplemented with N-(2-chloro-4-pyridyl)-N'-phenylurea(CPPU)treatments at different stages on seedlessness and fruit quality of 'Shine Muscat' grapevine were investigated in peak florescence and 2 weeks after blossoming,in order to provide some reference and guidance value for the production of grapevine seedlessness.The results as follow:1.GA3 and CPPU treatments had little effect on the growth of shoots and leaves of 'Shine Muscat'grapevine.2.Different concentrations of GA3 and CPPU treatments could significantly increase the seedless rate of the ' Shine Muscat' grapevine.Applying with 25 mg/L GA3+3 mg/L CPPU in peak florescence,25 mg/L GA3+5 mg/L CPPU at 2 weeks after blossoming(Treatment C)and 25 mg/L GA3+5 mg/L CPPU in peak florescence,25 mg/L GA3+ 5 mg/L CPPU at 2 weeks after blossoming(Treatment D),the seedless rate the 'Shine Muscat'grapevine as high as 100%.Meanwhile,the two berry weight and cluster weight increased significantly,fruit shape index decreased significantly,the berry tended to be round.3.Three treatments which is to apply with 50 mg/L GA3 in peak florescence,50 mg/L GA3 at 2 weeks after blossoming(Treatment F),50 mg/L GA3 in peak florescence,50 mg/L GA3+ 5 mg/L CPPU at 2 weeks after blossoming(Treatment G),and 50 mg/L GA3+5 mg/L CPPU in peak florescence,50 mg/L GA3+ 5 mg/L CPPU at 2 weeks after blossoming(Treatment H)for the berry weight had no significant difference with CK.But other treatments could significantly increase the berry weight.4.Co-treatment with lower concentrations of GA3 and CPPU could significantly improve the fruit seedless rate,transverse diameter,berry weight and fruit firmness.Meanwhile,the total soluble solids increased,but the total acid content showed the trend of reducing.By applying co-treatment with lower concentrations of GA3 and CPPU promoted the fruit mature and improved fruit flavor.5.Comprehensive consideration for the seedless rate and fruit quality of the 'Shine Muscat'grapevine,the best co-treatment in production is to apply with 25 mg/L GA3+5 mg/L CPPU in peak florescence,and 25 mg/L GA3 + 5 mg/L CPPU at 2 weeks after blossoming(Treatment D).The treatment could effectively improve the fruit commodity and increase economic benefits,which can be used for the production practice of the 'Shine Muscat' grapevine.