Research On Induced Mechanism Of Atailing And Dufulin For Banana Sigatoka Leaf Spot Disease

Banana sigatoka leaf spot disease is one of the serious diseases in banana production.It may cause reduction of production and quanlity duo to the erroneous treatments.Fungicides are used frequently in banana production as banana leaf spot can easily occur.However,frequent use of fungicides can cause environment pollution.Our present research goal is to induce disease resistance of plants by utilizing the the potential resistance of plants to increase the activation or expression of the disease-resistant genes.In the present study,six kind of resistant inducers were used to induce the disease resistance of banana leaf spot.Moreover,the mechanism of the induced disease resistance of ATailing and Dufulin was studied.The results was reported as followed:1.six kind of resistant inducers had different antifungal activities to Mycosphaerella musicola.The high concentration of scopoletin,Dufulin and Gentisic acid had high antifungal activities,and the inhibitory rate of Scopoletin,Dufulin and Gentisic acid could reached 80%at least after inoculation 120 h.However,the inhibitory rate of Probenazole,and Micromolecule inducer with all concentrations and the ATailing with low concentrations had lower antifungal activities after inoculation 120h.2.six kind of resistant inducers were used to induce against banana leaf spot.The best antifungal activities for bananas leaf spot is the Dufulin with 2.5g/L and the resistance induced by it was 30.21%,32.30%and 41.39%after treatment 20 d,30 d,and 40 d,respectively.Then,the second antifungal activities for banana leaf spot is the ATailing with lg/L and the resistance induced by it was 23.00%,24.35%and 21.11%after treatment 20 d,30 d and 40 d,respectively.3.After the treatment of banana with ATailing and Dufulin,both soluble phenol and MDA were changed compared with the controls.The soluble phenol content has a certain increase;MDA content has a certain reduction.However,the differences compared to the controls were not significant.4.After the treatment of banana with ATailing,four defense enzymes activity were changed compared with the controls.The activities of PAL,SOD,and POD were significantly increased,but the activity of PPO was increased softly.Moreover,after the treatment of banana with Dufulin,four defense enzymes activity were changed compared with the controls.The activities of PAL,PPO,and POD were significantly increased,but the activity of PPO was increased softly.5.Dufulin had no significant effect on banana roots' activity,chlorophyll-a,chlorophyll-b,soluble sugar and soluble protein.However,atailing had a certain lifting effect on banana soluble protein and soluble sugar in the later period,but had no significant effect on banana root activity,chlorophyll-a,and chlorophyll-b.6.After the treatment of banana with ATailing and Dufulin,the chitinase gene expression were up-regulated in all exposure times excepted that the treatment of 144 h with Dufulin in which the chitinase gene expression were down-regulated.The relative expression level of chitinase gene was highest at 72 h with the two resistant inducers compared with other exposure times.The resistance of bananas sigatoka leaf spot disease is closely related to PAL,SOD,PPO POD,chitinase and litter related to roots' activity,chlorophyll-a,chlorophyll-b,soluble sugar and soluble protein.