Study On Healing Agent For Almond Gummosis And It's Effect On Biochemical Resistance Indexes

Almond gummosis is caused by BotryosPhaeria dothidea(Moug.ex Fr.)Ces.et de Not. The bacteria is a class of world-wide distribution pathogenic fungi. The main pesticides for controlling this disease have a certain control effect, but long-term use have made resistante to this bacteria. Taking the agents on healthy tissue around the wound into account, these fungicides are not suitable for long-term single use. 8 - hydroxy-quinolinone is a kind of new high efficiency and low toxicity biocides. It has killing effect on both fungi and bacteria. 8-Hydroxyquinolinone has been widely used because of its stable performance, security and low toxicity. So it is necessary to carry out research on gum disease prevention and treatment of almond.In this study, Almond" NONPAREIL " as the test material, The antibacterial activity of several fungicides on Botryosphaeria dothidea were determined. The field trials efficacy against almond gummosis were conducted. In addition, the change of disease-related substances and enzyme activity in leaves of diseased plants smeared with healing agent were also measured. The results showed that:1. The toxicity of 8 - Hydroxyquinoline in inhibitting mycelial growth of BotryosPhaeria dothidea(Moug.ex Fr.)Ces.et de Not was high. The EC50 value and the EC90 values were 1.272μg/mL and 8.072μg/mL, which were much better than conventional fungicides; The pharmaceutical could made mycelial grow slow, branching increase. The pharmaceutical had significant detrimental effect on the cell membrane. After 60min, the conductivity continued to rise. The conductivity was 40μs/cm at the concentration of 1μg/mL.2. Four medicaments contained four different concentrations of 8– Hydroxyquinoline were selected to smear on the disease plants. The results showed a certain degree of control effect. When the concentration of 8– Hydroxyquinoline was 403.6mg/L, The field average disease index was only 6.94 and the control effect was 89.80%, which was significantly superior to conventional fungicides.3. Polyvinyl acetate emulsion, polyvinyl alcohol, 8-hydroxyquinoline, NAA(6-BA), distilled water and ethanol were made into healing agent. Apply wound with healing agent, the results showed that: The healing rate of the healing agent with 200mg/L NAA was the highest, reaching 89.80%.4. After smearing healing agent on diseased plants, the content of MDA, lignin, soluble sugar,total phenol and the enzyme activities in almond leaves had undergone significant changes. The healing agent added NAA at concentration of 200mg/L made the content of Lignin, soluble sugar, total phenol and the activity of PPO, POD and PAL significantly rise.