| Wound healing is a typical response of wounded potato tubers.However,naturally healing takes a longer time for the tubers,tubers are susceptible to fungal and bacterial pathogens during healing,which causes a serious decay during storage of tubers.Therefore,it is necessary to take messures to accelerate the healing of tubers.Stroby is a broad-spectrum green bio-source fungicide with high safety.In this study,the potato cultivar ’Longshu No.7’original-seed was used as test material.The tubers of original-seeds were soaked with 0.4mg/L Stroby and then planted in open-air fields.The plants were sprayed for three times with0.4 mg/L Stroby on the 7th,56 th and 80 th days after flowering of plants.The effect of Stroby treatment on the plant growth,and the storage of intact harvested tubers were evaluated.The weight loss and disease index of wounded tubers were determined during healing.The accumulation of suberin and lignin at the wound sites were observed,and the activity of active oxygen,phenylpropanate,fatty acid metabolisms were analyzed at wound sites of tubers.The results showed as below:1.Stroby treatment effectively increased the number of leaves,plant height and stem diameter of plants,enhanced the number of per plants tuber and the yield per plant,and reduced the disease index of late blight of plants.In addition,Stroby significantly reduced the weight loss and natural incidence of tubers during storage.Among them,the treatment of soaking seeds combined with spraying showed the best effect,followed by soaking seeds.However,Stroby had no significant effect on the germination rate and bud length of tubers during storage.2.Stroby effectively reduced the weight loss and disease index of wounded tubers during healing.In addition,the chemical promoted the accumulation of suberin polyphenol,subrein polyester and lignin at the wound sites during healing.The treatment of soaking seeds combined with spraying showed the best effect,followed by soaking seeds.3.Stroby reduced cell membrane permeability and malondialdehyde content,accelerated the production rate of superoxide anion and increased the content of hydrogen peroxide at wounded sites of tuber during healing.At the same time,the chemical increased the activity of superoxide dismutase,catalase,ascorbate peroxidase,glutathione reductase,and monodehydroascorbate reductase.Stroby also effectively increased the content of reduced glutathione at wounded sites of tuber during healing.4.Stroby enhanced the activity of phenylalanine ammonia-lyase,cinnamic acid hydroxylase,4-coumaroyl-coenzyme A-ligase,cinnamyl alcohol dehydrogenase,cinnamoyl-Co A reductase,tyrosine hydroxy cinnamoyl transferase at wounded sites of tuber during healing.At the same time,the treatment also effectively promoted the content of total phenols,flavonoids,lignin and phenolic acid at wounded sites of tuber during healing.Moreover,the chemical promoted the activity of fatty acyl-Co A reductase,3-ketoacyl-Co A synthase,ferulyltransferase and glycerol-3-phosphate acyltransferase at wounded sites of tuber during healing.It is suggested that preharvest Stroby treatments promote potato growth,increase tuber yield,enhance plant resistance against late blight.The chemical significantly reduce weight loss and natural incidence of tubers during storage.Preharvest Stroby treatments accelerate the wound healing of harvested tubers,which is closely related to the activation of reactive oxygen species,phenylpropanoids and fatty acid metabolism at wounded sites of tuber during healing. |
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