Study On Optimization And Evaluation Of Seed Falling Control Technology Of Thompson Seedless Grape

Thompson seedless grapes are both fresh and dry grapes.A small amount of them are used to make white wine.They have the characteristics of thin peel,tender meat,high sugar content and good taste.However,there are some problems such as small fruit stem and short fruit brush,which makes Thompson seedless grapes prone to fruit falling in the process of picking,storage and transportation,resulting in great losses.In order to reduce the loss of Thompson seedless grapes caused by grain falling,some special treatment methods are used to treat Thompson seedless grapes in growth period,such as PGR,girdling and calcium fertilizer treatment,which can reduce the post harvest grain falling rate to a certain extent.Taking the Thompson seedless grape in Gaochang District of Turpan as the experimental material,the Thompson seedless grape was treated before harvest and stored at low temperature after harvest to study the effects of different treatment methods on the grain falling and quality of Thompson seedless grape.The results are as follows:（1）Determination of treatment basis and time:spray GA₃ and CPPU on inflorescence and ear respectively before and after anthesis.On this basis,treat Thompson seedless grape 50 days after anthesis and 70 days after anthesis.Use different concentrations of Me JA,NAA+6-BA,PCPA,single concentration of S-ABA,2,4-D,trunk girdling,fruiting mother branch girdling and combined treatment.（2）Compare the Postharvest of different treatments.The Postharvest Thompson seedless grapes were quickly stored in the-2℃cold storage,and taken out in batches after 3,13 and 23days.The seed drop rate,stem pulling and seed drop mode of Thompson seedless grapes were measured during storage.The results showed that the above treatments could effectively reduce the seed drop rate of Thompson seedless grape.Among them,the seed drop rate of Thompson seedless grape treated with 2,4-D and NAA+6-BA was the lowest,which was 76.56%and 76.95%lower than that of the control group,respectively;The best girdling treatment was the girdling of fruiting mother branch,which reduced the grain falling rate by 62.9%;In the combined treatment,both girdling and non girdling can greatly reduce the seed drop rate of Thompson seedless grape,with an average of 9.18%and 10.92%,40 mg/L PCPA,100 mg/L NAA+6-BA,5μmol/L and 50μmol/L The grain rate of Me JA was the lowest in the corresponding plant growth regulator treatment,the tensile force of fruit stalk increased,and the way of grain falling was always abscission.（3）2,4-D and CPPU were used to detect pesticide residues in related treated Thompson seedless fruits,and the two residues met the relevant requirements.（4）After harvest comparison of different treatments,the fruit quality of Thompson seedless grape under different treatments was measured.The results showed that the single grain weight under Me JA treatment was the largest,which was 2.95 g,and the solid acid ratio under 2,4-D treatment was the highest,which was 54.89.Under the principal component analysis,2,4-D treatment was the best,with a comprehensive score of 2.14,followed by the results:mother branch girdling>trunk girdling>S-ABA Me JA>CK>combined non girdling>combined girdling>NAA+6-BA.Therefore,2,4-D,fruiting mother branch girdling,trunk girdling,S-ABA and Me JA are helpful to improve the quality of Thompson seedless fruit,and NAA+6-BA has a significant inhibitory effect on the quality of Thompson seedless fruit.（5）Verification of 2,4-D stem pulling force under tissue culture conditions.Taking mature Thompson seedless grapes as materials,the method of hanging culture with stem was adopted.2,4-D with a concentration of 25 mg/l was added to MS medium,and the stem pulling force was measured after 6 days.The results showed that 2,4-D could significantly increase the stem pulling force of Thompson seedless grape,which was 178.57%higher than that of the control group.