| There is a worldwide trend to explore new biocontronl methods that control pathogenic diseases, giving priority to methods that reduce disease incidence and avoid negative and side effects on human health as a result of the excessive application of synthetic fungicides. In addition, the emergence of fungicide-resistant strains of microorganisms and the continuous rigorous regulation of fungicide use and disposal has reduced the possibility to conceive control strategies based on chemicals.The objective of this study was to assess the effects of HRO-C48 in combination with endophytic Chaetomium globosum ND35, chitosan or VB1 on the induced systemic resistance against B. cinerea, and to determine the application potential by combination different types of biocontrol agents or chemical compounds to improve biocontrol of plant diseases,as well as provide an alternative to chemical control for preventing gray mould damage. The strain either alone or in combination with chitosan VB1 or Chaetomium globosum ND35 to be determined for antifungal activities and inducing defense reactions in tomato and bean plants inoculated with Botrytis cinerea, the causal agent of grey mould was studied by confrontation bioassay in vitro and in greenhouse experiments in vivo.1. Supplemented with different concentrations of chitosan into PDA plates, confrontation bioassay in vitro showed that the antifungal activity by strain HRO-C48 against the phytopathogenic B. cinerea was stronger than that on PDA-free, and the maximum inhibitory activity was 36.98 % at the concentration of 1.00 mg ml-1 of chitosan. While the direct inhibition by concentrations of VB1 0.05 mol / L was 31.03 %. The results of inhitition of spore germination showed that when Chitosan at 3.00 mg ml-1 the inhibition was from 48.93 % to 74.45 %.2. The test of resistance induced by HRO-C48 in greenhouse combined with different concentrations of Chitosan and VB1 showed that treatments seeds of bean and tomato soaked and poured root with HRO-C48 suspension firstly, then inoculated with Chitosan and VB1, diameter of disease lesion decreased notably. And the better effects of biocontrol were treatments C48+3 mg ml-1 and C48+0.05 mol / L, respectively.3. Under greenhouse experiments, we study 3 mg ml-1 chitosan solution to promote tomato plants growing. The results showed that plant growth were promoted after treated by chtosan than the control within one month, especially the weight of roots.4. Seeds of bean or tomato were soaked and poured root with HRO-C48 suspension firstly, then inoculated with endophytic Chaetomium globosum ND35 or treated with chitosan,VB1, the induced systemic resistance was evaluated according to the lesion size of leaves. Results suggested that Serratia plymuthica HRO-C48 in combination with other agents such as chitosan,VB1 or biocontrol fungus might more effectively protect host plant from grey mould than HRO-C48 alone,and the control effects were 46.17 %,59.98 % and 54.84 %, respectively. Plants of cucumber were induced resistance to damp-off markedly, and the effect of control was promoted to 62.33 %.5. Under greenhouse experiments, when HRO-C48 and other elements applied together, effect of induced plants resistance were observed by determining PR-proteins and phenolic compounds. Dynamic of PAL,PPO,POD activity and content of phenolic compounds were monitered. All the treatments with pathogeny were more active than without B. cinerea. And proteins increased gradually after treated by combinations. All types of enzyme activities and phenol content of treatments without pathogeny were to maximum at 4d, 6d and 8d, while treatments of incubated B. cinerea were to maximum activity at 6d to 8d.
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