›› 2020, Vol. 32 ›› Issue (3): 460-468.DOI: 10.3969/j.issn.1004-1524.2020.03.11

• Plant Protection • Previous Articles     Next Articles

Isolation, identification and characterization of antagonistic actinomycetes A10 and A17 against Botryodiplodia theobromae

GUO Xuesong1, TIAN Libo1, SHANG Sang2,*, ZOU Kaixi1, CHEN Hongrong1, LI Wanyu1, YUE Xiaoqi1   

  1. 1.College of Horticulture, Hainan University/The Key Laboratory of Tropical Horticultural Crop Quality Regulation of Hainan Province, Haikou 570228, China;
    2.College of Life Science and Pharmaceutical Sciences, Hainan University, Haikou 570228, China
  • Received:2019-11-23 Online:2020-03-25 Published:2020-04-03

Abstract: In order to enrich the antagonistic and antibacterial resources of mango stem-end rot and find a non-toxic and non-polluting post-harvest control method instead of chemical fungicide, plate dilution method, scribing purification method and paper diffusion method were used to separate and screen the antagonistic actinomycetes against Botryodiplodia theobromae from mangrove rhizosphere soil. Their taxonomic status was identified, the fermentation conditions were optimized, and the biological control effect was tested. A total of two antagonistic actinomycetes A10 and A17 with strong antibacterial activity against postharvest mango rot fungus (Botryodiplodia theobromae Pat.) were screened. According to the morphological characteristics, physiological and biochemical characteristics and molecular identification, the two actinomycetes were all Streptomyces. The fermentation medium and fermentation conditions of A10 strain were optimized as follows: 2.5% lactose, 2.0% peptone, initial pH 8.0, shaking speed 200 r·min-1, culture time 120 h. The fermentation medium and fermentation conditions of A17 strain were optimized as follows: 2.0% soluble starch, 2.0% peptone, initial pH 7.0, shaking speed 200 r·min-1, culture time 120 h. In vivo experiment, on the 4th day, the incidence and disease index of the control group treated with sterile water were 81.7% and 52.5, respectively, 43.3% and 21.7 in the A10 group, 36.7% and 17.5 in the A17 group, and 16.7% and 12.2 in the 450 mg·kg-1 prochloraz group. Both strains had a certain inhibition effect on the occurrence and expansion of the disease spot, and A17 had a certain inhibition effect on the expansion of the disease spot. There was no significant difference between the inhibitory effect of A17 and that of 450 mg·kg-1 prochloraz. The results showed that the two strains had some antagonistic effect on the pathogen, which could be further studied.

Key words: mango stem-end rot, antagonistic actinomycetes, screening, identification, control effect

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