Toxicity of Pythium oligandrum broth to animal and its control effect on rot diseases caused by Penicillium italicum and Penicillium digitatum in orange fruit storage

Abstract:

Abstract:［Objective］In order to develop a safe，nontoxic and efficient biological antistaling agent and to decrease the incidence of rot diseases caused by the Penicillium italicum and Penicillium digitatum in orange fruit storage，［Methods］the present experiment was carried out with Pythium oligandrum broth (POB) produced by our self- isolated strain (P．oligandrum CQ2010) to study the toxicity to animal． Thereafter，mycelium growth and spore germination of both P．digitatum and P． italicum and control effect of rot disease in orange storage were compared after treated by liquid culture medium (control)，POB，prochloraz (PC)，and PC+POB.［Results］Gastric lavage with large amount POB did not influence mouse weight． The animals also showed no abnormality in appearance，behaviors and pathology changes in heart，liver，kidney，lung and intestine． POB decreased the hyphal growth by 70.24%－93.74% and spore germination by 44.91%－87.82% (24 h after POB addition) of these two pathogenic fungi． Disease incidence of orange fruit following P.italicum inoculation changed in the sequence: CK＞POB＞PC＞PC+POB and the control efficacy behaved otherwise．In commercial simulation storage，the disease incidence of orange fruit caused by P．digitatum and P．italicum was above 50% of the total．The fruit rot rate was 26.40% (CK)，15.03% (POB)，16.61% (PC) and 4.21% (PC+POB)．There were no significant differences in fruit quality under different treatments.［Conclusion］POB was safe to animal and could decrease rot disease incidence caused by P. italicum and P. digitatum in orange storage whereby producing a positive interaction with prochloraz and controlling rot diseases caused by these two fungi.