Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (10): 2958-2965.DOI: 10.3969/j.issn.1000-2561.2021.10.028

• Plant Protection & Bio-safety • Previous Articles     Next Articles

Isolation, Identification and Bacteriostasis Study of Endophytic Bacteria to Control Colletotrichum Leaf Disease on Rubber Tree

LI Lanlan, DAI Liming, JIANG Guizhi, LIU Yixian, SHI Yuping, CAI Zhiying*()   

  1. Yunnan Institute of Tropical Crops, Jinghong, Yunnan 666100, China
  • Received:2020-11-16 Revised:2021-02-08 Online:2021-10-25 Published:2021-11-25
  • Contact: CAI Zhiying

Abstract:

At present, the disadvantages of chemical pesticides are prominent and the development of environmental friendly biocontrol agent is needed. The screening of biocontrol strains with inhibition of rubber anthracnose can reserve resources for the development of new biocontrol agents. The endophyte bacteria of rubber trees were isolated and purified by tissue culture, and growth plate-confrontation was used to screen antagonistic strains. Strain Bac RZS3D4-1, Bac RZS3D4-2, Bac RZS3D4-3, Bac RZS3D4-4 were identified based on morphological, physiological, biochemical characteristics and the phylogenetic tree was constructed with 16S rRNA and gyrA gene sequence. The growth plate-confrontation was used to study the antimicrobial persistence, stability and broad spectrum of endophytic bacteria. The Oxford cup method was used to study the sensitivity of antagonistic endophytic bacteria to fungicides. Four strains of bacteria (Bac RZS3D4-1, Bac RZS3D4-2, Bac RZS3D4-3, Bac RZS3D4-4) were isolated from the healthy root tissues of rubber trees. Phylogenetic tree analysis showed that the four strains were closely related to Bacillus amyloliquefaciens, and the culture traits and physiological and biochemical characteristics were similar to those of B. amyloliquefaciens. The results showed the strains had strong antibacterial persistence and good antibacterial stability, strong antibacterial activity against Colletotrichum acutatum (DFMP1E and Mlzzp3) and Pestalotiopsis microspora (MF375898), and weak inhibitory effect on Fusarium solani (XJ160901). They were not sensitive to carbendazim, isocarb, chlorothalonil and difenoconazole, so it is expected to be developed as a biocontrol agent.

Key words: Colletotrichum leaf disease on rubber tree, Bacillus amyloliquefaciens, biocontrol endophytic microorganism, isolated identification

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