Isolation of endophytes from Panax quinquefolium and screening and identification of strains with antagonistic activity / 中草药

ABSTRACT

Objective: To study the resource situation of endophytes in Panax quinquefolium of Jilin province and to select the endophytes with antagonistic effect on pathogenic fungi of P. quinquefolium. Methods: The strains with the antagonistic activity were screened by applying mixed strains method during preliminary screening and adopting the antagonism method of fermentation liquor in re-screening; Besides, the selected endogenous strains were identified via 16 S rDNA and ITS method. Results: Thirty-four endogenous strains were isolated from P. quinquefolium. After preliminary screening and re-screening, six strains with good antagonistic effect on pathogenic fungi of P. Quinquefolium were selected B3, B11, B17, B23, B24, and F10. Among them, B3 showed an inhibitory effect on seven pathogenic fungi; F10 had a good inhibitory effect on Cylindrocarpon destructans and Alternaria panax, with an inhibitory zone diameter over 35 mm; According to the identification, B3 and F10 were Bacillus methylotrophicus and Penicillium citreonigrum respectively. Conclusion: Endophytes in P. quinquefolium are diversified and there also exist strains with high antagonistic activity, which can be a good source for biocontrol bacterium and fungus of P. quinquefolium diseases.