Study On The Mechanism And Control Technology Of Postharvest Berry Dropping Rate Of White Grape Seedless

Xinjiang white grape seedless is a variety that can be freshly edible and dried.However,the skin of white grape seedless is weak,the meat of white grape seedless is fresh and tender,and the fruit brush is short,and it is easy to cause the mechanical damage and the dropping of fruit particles in the transportation process,resulting in great economic loss.It is particularly important to use some plant growth regulators to deal with white grapes seedless pre-harvest,and to reduce the berry dropping of white grapes seedless post-harvest.In this paper,Turpan white grape seedless is used as the test material,and the growth regulator is used in different growth stages pre-harvest.1-MCP is used to treat it post-harvest,and they are stored in low temperature.The effect of the berry dropping rate and quality of white grape seedless is studied.The specific research contents are as follows;1.Determination of the optimal spray concentration of white grape seedless.The white grape seedless is used to be treated spike spray at the 20 d,15 d,5 d before the harvest,with the different concentrations of GA3,NAA and the liquid 1-MCP processing the pre-harvest spike spray.The change of the quality index of white grape seedless in the storage process is evaluated by using the three indexes of the decay rate,berry dropping rate and stem browning rate,and the optimal spraying concentration is selected.The results show that 40 mg/L GA3,100 mg/L NAA,and liquid 100 mg/L 1-MCP,could effectively inhibit the increase of berry dropping rate,decay rate,and stem browning rate in the storage process of white grape seedless.2.The white grape seedless is used to compare pre-harvest and post-harvest treatment.Regularly determine the change of the decay rate,berry dropping rate,SSC,TA,Vc and stem browning rate of white grapes seedless in the storage process,and study the effect of the quality and the berry dropping rate of white grape seedless in the storage period.The results show that the post-harvest treatment of white grape seedless can significantly reduce the decay rate of fruit,reduce the speed of berry dropping rate of white grape seedless,delay stem browning of fruit,and delay the decline of Vc and titratable acid content.3.The white grape seedless is used to compare pre-harvest and post-harvest treatment.Under the condition that white grapes seedless are stored at low temperature(-1?±0?,RH 90%-95%),discuss the influence of different treatment on antioxidant enzymes and the defense system of white grape seedless.The results show that post-harvest treatment can effectively prolong the time of SOD activity peak,delay the decline of CAT,inhibit the increasing speed of POD,improve the activity of APX,and reduce the accumulation rate of O2-and H2O2 in the fruit,compared with pre-harvest treatment.4.The white grape seedless is used to compare pre-harvest and post-harvest treatment.Study the PAL,GLU in the fruit of grapes and the activity of CX,LOX causing berry falling and high performance liquid chromatography(HPLC)method is used to determine the content change trend of GA3,IAA and ABA,the three endogenous hormones.The results show that compared with pre-harvest treatment,post-harvest treatment can improve the activity of PAL and GLU,and inhibit the activity of CX and LOX causing the berry dropping in the fruit.Post-harvest treatment can effectively inhibit the increase of ABA content in the grape ionospheric region,while reducing the content of IAA and GAs,thus inhibiting the formation of the ionospheric regions and reducing the berry dropping rate.