Effects Of Potassium Fertilizers Rate On Sugar Accumulation And Related Enzymes Activities In 'Hong Deng' Sweet Cherry

In this study,the sweet cherry of growth in Buwa Village of Wenchuan County,‘Hong Deng',was selected as the research object;the effects of potassium fertilizers(potassium sulfate)rate on sugar content and their correlative enzymes activities for the cherry which has different yield per plant of the period from 15 days after anthesis to fruit complete development were studied.The cherry plants were divided into three grades by yield: 40-55 kilogram per plant(the large tree),25-40 kilogram per plant(the medium tree),25 kilogram and below per plant(the little tree).The results are as follows:For the cherry with yielding 40-55 kilogram per plant(the large tree),the optimization scheme is to use 2.5 kilogram compound fertilizer plus 1.25 potassium sulfate for each plant from 15 days after anthesis.Compared with local conventional fertilization,under such scheme,the single fruit weight was increased by 17.16%,the soluble solid content was increased by 18.90% the titratable acid content was decreased by 8.90%,the soluble sugar content was increased by 5.30%,Vc was increased by 15.50%,and the glucose content was increased by 14.22%,fructose content was increased by 12.51%,sucrose content was increased by 12.51%,sorbitol was increased by 15.17%,soluble acid invertase activity was maximally increased by 26.10%,soluble neutral invertase activity was maximally increased by 30.51%,the activity of sorbitol dehydrogenase was maximally increased by 20.69% and the activity of sorbitol oxidase was maximally increased by 19.42%.For the cherry with yielding 25-40 kilogram per plant(the medium tree),the optimization scheme is to use 1.75 kilogram compound fertilizer plus 0.75 potassium sulfate for each plant from 15 days after anthesis.Compared with local conventional fertilization,under such scheme,the single fruit weight was increased by 17.16%,the soluble solid content was increased by 18.90%,the titratable acid content was decreased by 8.90%,the soluble sugar content was increased by 5.30%,Vc was increased by 15.50%,the glucose content was increased by 14.22%,fructose content was increased by 12.51%,sucrose content was increased by 12.51%,sorbitol was increased by 15.17%,soluble acid invertase activity was maximally increased by 26.10%,soluble neutral invertase activity was maximally increased by 30.51%,the activity of sorbitol dehydrogenase was maximally increased by 20.69% and the activity of sorbitol oxidase was maximally increased by 19.42%.For the cherry with yielding 25 kilogram and below per plant(the little tree),the optimization scheme is to use 1.0 kilogram compound fertilizer plus 0.375 potassium sulfate for each plant from 15 days after anthesis.Compared with local conventional fertilization,under such scheme,the single fruit weight was increased by 9.23%,the soluble solid content was increased by 13.30%,the titratable acid content was decreased by 13.84%,the soluble sugar content was increased by 7.71%,Vc was increased by 12.17%,the glucose content was increased by 12.55%,fructose content was increased by 12.49%,sorbitol was increased by 14.83%,soluble acid invertase activity was maximally increased by 32.89%,soluble neutral invertase activity was maximally increased by 20.38%,sorbitol dehydrogenase activity was maximally increased by 22.42% and the activity of sorbitol oxidase was maximally increased by 17.32%.In conclusion,the study indicated that the proper amount of potassium fertilizer(potassium sulfate)can not only significantly increase the content of glucose,fructose,sorbitol and sucrose as fruit grow,but also markedly improve the activity of soluble acid invertase,soluble neutral invertase and sorbitol dehydrogenase.Through increasing activity of soluble acid invertase and sorbitol dehydrogenase to improve transformation efficiency of sucrose and sorbitol into glucose respectively,the glucose content in the fruit was increased,which can guarantee the growth and quality of cherry.Throughout the experiment,the activities of soluble acid invertase and soluble neutral invertase showed an increasing trend,while sorbitol dehydrogenase activity kept highly active during all development which lead to less sucrose in the fruit.