中文摘要：

[目的]拟从马来西亚植物根际土壤中分离和鉴定抑菌能力强的芽孢杆菌菌株,并对菌株产生的脂肽类抗菌物质的种类以及生防效果进行研究。[方法]采用平板对峙试验,筛选具有抑制水稻白叶枯病菌和油菜菌核病菌的芽孢杆菌,基于16S r DNA、gyr B基因序列对分离菌株进行分类鉴定,采用基质协助激光解吸附/电离-飞行时间质谱（MALDI-TOF-MS）法鉴定菌株所产生的脂肽类抗生素的种类,并通过温室试验对菌株防治水稻白叶枯病的效果进行研究。[结果]拮抗试验结果表明：D15、W3、Klu7、YM16、D1和PLZ26这6株菌株对水稻白叶枯病菌或油菜菌核病菌具有较强的抑制活性,其中菌株D15和W3对这2种病原菌都具有抑制活性。基于16S r DNA和gyr B基因的系统发育分析表明：菌株D15和W3为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）;菌株Klu7属于短小芽孢杆菌（B.pumilus）;菌株YM16属于蜡样芽孢杆菌（B.cereus）;菌株D1和PLZ26属于苏云金芽孢杆菌（B.thuringiensis）。MALDI-TOF-MS检测结果表明：菌株PLZ26和Klu7能产生脂肽类抗生素Surfactin;D15和W3能产生脂肽类抗生素Iturin A。温室生防试验结果表明：菌株PLZ26对水稻白叶枯病具有较好的防治效果。[结论]本研究为生物农药的研发提供了优良的菌株资源。

英文摘要：

[Objectives]The main purpose of this study is to screen the Bacillus spp. with high antimicrobial activity from the rhizosphere soil of Malaysia. The lipopeptides produced by the Bacillus strains were identified,and biocontrol activities of these strains were evaluated. [Methods]The analysis of antagonistic activity was used to screen the Bacillus spp. with strong antagonistic activities against Xanthomonas oryzae pv. oryzae or Sclerotinia sclerotiorum. The phylogenetic tree based on the sequences of 16 S r DNA and gyr B gene was used to identify the isolated Bacillus spp. strains. The matrix-assisted laser desorption / ionization-time of fligh mass spectrometry（ MALDI-TOF-MS） was used to analyze the lipopeptide compound produced by the isolated strains. The greenhouse expriments were performed to evaluate the biocontrol effect on rice bacterial leaf blight of Bacillus spp. strains. [Results]The results of antagonistic activities showed that six isolated Bacillus strains（ D15,W3,Klu7,YM16,D1 and PLZ26） have significant inhibitory activities against Xanthomonas oryzae pv. oryzae or Sclerotinia sclerotiorum,and among these strains,D15 and W3 have inhibitory activities to both of them. Phylogenetic tree indicated that these six isolates were identified to be most closely related to Bacillus amyloliquefaciens（ D15 and W3）,B. pumilus（ Klu7）,B. cereus（ YM16） and B. thuringiensis（ D1 and PLZ26）. Lipopeptide compound analysis via MALDI-TOF-MS showed that PLZ26 and Klu7 produced Surfactin,and strains D15 and W3 produced Iturin A. The evaluation of the biocontrol effect showed that PLZ26 has good control effect on bacterial blight of rice. [Conclusions]This study provided the bacterial resources for the research and exploitation of biopesticides.