两株樟树促生抗病内生细菌的分离、筛选及鉴定

【目的】解决城市绿化用樟树黄化病、溃疡病近年来多发的情况。【方法】本研究采集了上海地区健康的行道樟树枝条,分离、筛选并鉴定具有促生抗病作用的樟树内生细菌。通过组织切片法、组织匀浆法从健康樟树组织中分离内生细菌,再通过与2种樟树病害的病原菌进行平皿对抗试验,筛选出对樟树病害具有拮抗作用的菌株,同时还研究了拮抗细菌的解无机磷、解有机磷能力,以及分泌吲哚乙酸(IAA)的能力和耐盐性。在上海嘉定进行了施用优良菌株的田间试验,统计其促进生长情况。【结果】从樟树组织中分离到候选内生细菌共50株,其中有11株菌对樟树病害病原菌具有拮抗效果,4株菌具有解无机磷能力,2株菌具有解有机磷能力,2株菌具有产IAA能力,5株菌有较好的耐盐性。对其中综合性状优秀的2个菌株进行种类鉴定,菌株ZS-1被鉴定为微杆菌(Microbacterium resistens),菌株ZS-3被鉴定为巨大芽孢杆菌(Bacillus megaterium),发现2株菌对樟树扦插苗株高有较好的促生效果。【结论】筛选鉴定了樟树体内的2株优良内生细菌,为樟树促生抗病优良内生菌的研究与应用奠定了良好的基础。

Isolation,screening and identification of endophytic bacteria from Cinnamomum camphora that promote growth and antagonistic pathogen

【Objective】Determine the underlying cause of chlorosis in urban greening and canker of Cinnamomum camphora (L.)Presl. 【Method】 We collected the branches and leaves of camphor-tree of Shanghai area, and aimed to isolate endophytic bacterium from camphor-tree. The isolated strains were screened and identified. They could antagonize pathogenic fungi of camphor-tree via phosphorus-solubilizing ability. The endogenous bacteria were isolated from healthy branches and leaves of camphor-tree by tissue slicing method or tissue homogenation method. The endophytic bacteria were screened against the pathogenic fungi in plate for determining the effect of resolved inorganic phosphorus and organic phosphorus by Molybdenum antimony colorimetric method, the effect of indole acetic acid(IAA)production by Salkowski colorimetric method, and its salt resistance.【Result】 Fifty candidate strains were isolated from camphor-tree, of which 11 strains were antagonistic to the pathogens of camphor-tree, 4 strains showed the effect of resolved inorganic phosphate, and 2 strains showed the effect of resolved organic phosphorus. Two strains had the ability of IAA generation, and 5 strains had different salt resistances. Considering the excellent traits, strain ZS-1 was identified as Microbacterium resistens and strain ZS-3 was identified as Bacillus megaterium. Both these strains could increase the height of camphor-tree.【Conclusion】This study reveals the species of endophytic bacteria in camphor-tree and establishes the basis for the biological control and promote the growth of camphor-tree. This study for the first time aimed to determine the underlying causes of diseases in urban greening through the screening of endophytic bacteria from healthy branches and leaves of camphor-tree in Shanghai.