Study On The Off-season Flower Promotion And Related Physiological Mechanism Of Vietnamese Green Pomelo

Vietnamese Green pomelo is a pomelo variety introduction of Vietnam in recent years.Its characteristic is that it blooms many times a year in its original place.However,the flowering and fruiting habits of Vietnamese green pomelo introduced in Guangxi are not yet clear,and it is difficult to guide cultivation and adjustment of production period.In order to understand the flowering pattern of Vietnamese green pomelo in Guangxi and its main influencing factors,explore the feasibility of off-seasonal flowering of Vietnamese green pomelo,and provide a theoretical basis for the introduction and cultivation of Vietnamese green pomelo and the control of off-seasonal flowering.In this study,three-year-old Vietnamese green pomelo was used as the test material.From June 2019 to January 2020,a green green pomelo flower promotion experiment was conducted at Fenghejin Agricultural Base,Minfu Village,Yashan Town,Bobai County,Yulin City,Guangxi.A total of A（ring stripping）,B（ring cutting）,C（paclobutrazol 2g）,D（paclobutrazol 3g）,E（paclobutrazol 4g）,F（ring stripping + paclobutrazol 2g）,G（ring stripping + paclobutrazol 3g）,H（ring stripping + paclobutrazol 4g）,I（ring cutting + paclobutrazol 2g）,L（Comparison）12 flower-promoting treatments.Observe the temperature and humidity of the orchard,the results of different treatments,the thickness of the mother branch,flower formation,fruit setting,endogenous hormones,carbohydrates,amino acids and leaf nutrition Elements,etc.,to analyze the influence of different factors on fruit setting and the physiological mechanism of off-season flower formation of Vietnamese green pomelo.The main findings are as follows:1.The average thickness of the mother branches of A-K12 different treatments are: 6.767 mm,5.1mm,4.78 mm,5.18 mm,4.99 mm,6.46 mm,6.04 mm,4.36 mm,3.96 mm,4.54 mm and 3.9mm The control is 3.56 mm.Among them,the four treatments of ring stripping,3g paclobutrazol,ring stripping + 2g paclobutrazol and ring stripping + 3g paclobutrazol were significantly higher than the control,and the average thickness of the mother branch was the largest.2.The effect of different treatments is different.Among the 12 treatments,the rate of flowering plants in the ring-cut + 4g paclobutrazol treatment and the control was 0,and the remaining treatments could make the Vietnamese green pomelo flower.The rate of flowering plants in ring stripping and ring stripping + 2g paclobutrazol was 100%,which wasvery significant Higher than the control.3.The content of GA₃ before and after each treatment was significantly reduced,and the reduction of GA₃ with 2g paclobutrazol was the most significant,from 123.05 ng / g FW to 10.13 ng / g FW;Which indicated that the application of paclobutrazol,ring stripping and other flower promotion can inhibit GA₃ synthesis to a certain extent and promote flower formation.4.The ABA content of the ring-cut treatment showed a trend of decreasing first and then increasing during the flowering process,while the ABA content of the other treatments showed an upward trend.The ABA content of each treatment was significantly higher than that of the control,and the ABA content of the cyclopeel + 4g paclobutrazol treatment was the highest at 25.92 ng / g FW.5.The change trend of the soluble protein content in different treatments is basically the same,and it shows a trend of decreasing first and then increasing.The protein content of cyclopeel + 2g paclobutrazol treatment was the highest,reaching 16.21 mg / g,which was significantly higher than the control’s 7.7mg / g.The protein content of the ring cutting treatment is higher than that of the ring peeling treatment,but there is no significant difference between the two.6.Different treatments can increase the total amino acid content.Among them,the total amino acid content of 3g paclobutrazol treatmentis the highest,which is 959.09 mg / 100 g,which is significantly higher than the control’s 514.25 mg / 100 g.The total amino acid content of ring stripping is 872.25 mg / 100 g,which is significantly higher than the total amino acid content of ring cutting 686.79 mg / 100 g.7.The soluble sugar content of different treatments showed a trend of rising first and then falling.Except for the 2g paclobutrazol treatment,the soluble sugar content of the remaining treatments was significantly higher than that of the control.Among them,the soluble sugar content of3 g paclobutrazol treatment was the highest at 4.74%,which was significantly higher than that of the control at 3.87%.8.Among the 12 flower-promoting treatments,the contents of phosphorus（P）,zinc（Zn）,and potassium（K）treated by cyclic stripping +2 g paclobutrazol were the highest,being 15.41 mg / kg,0.0123 mg / kg,and 0.0053 mg,respectively./ kg,significantly higher than the control;2g paclobutrazol treated with the highest iron（Fe）content,0.189 mg / kg,significantly higher than the control.A certain amount of P,Zn,K,Fe in Vietnamese green pomelo leaves is beneficial to promote flower formation.Based on the results of this study,The ring stripping+2g paclobutrazol treatment has the best off-seasonal flower promotion effect on Vietnamese green pomelo.The principle is that ring stripping and paclobutrazol treatment can inhibit GA₃ synthesis,increase the ABAcontent,and increase the ABA / GA₃ value.At the same time,it can increase the leaf K,Zn,P,Fe,soluble sugar and protein content,provide energy and flower hormones for off-season flowering of Vietnamese green pomelo,so as to promote the off-season flowering of Vietnamese green pomelo.