黑麦草根际产铁载体细菌HMGY6B的筛选鉴定及对病原菌的拮抗作用

Screening, identification and antagonistic against the pathogens of a siderophore-producing bacteria HMGY6B from rhizosphere of ryegrass

【目的】从石灰性土壤中分离筛选出铁载体合成能力强、抗病效果好的菌株。【方法】采用刃天青(Chrome azural S,CAS)平板检测法,定性、定量筛选产铁载体能力较强的菌株,通过菌株形态、生理生化特征、16S r RNA基因序列相似性和系统发育分析,鉴定细菌类型,然后采用平板对峙法研究菌株与病原菌的拮抗作用。【结果】从多年生黑麦草根际土壤中分离得到一株产铁载体能力很强的菌株HMGY6B,经鉴定,该菌属假单胞菌属Pseudomonas菌株,其产生的儿茶酚型铁载体对黄瓜灰霉病(Botrytis cinerea)有显著的拮抗作用,在低铁条件下(0.16、2、5、10μmol/L FeCl_3)对黄瓜灰霉病的生长抑制率高达91.2%,但在富铁条件下(50μmol/L FeCl_3)降为30.2%,100μmol/L FeCl_3抑制率仅为5.5%。【结论】菌株HMGY6B可用于今后复合型抗病生物菌肥的开发研制。

[Objective] In order to isolate and screen a high-affinity siderophore-producing bacteria from calcareous soil, which has a significant effect on the pathogen. [Methods] High-affinity siderophore-producing strains were screened by chrome azural S（CAS） assay. Then, we take the methods of morphological observation, biochemical and physiological characteristics, 16 S r RNA gene sequence and phylogenetic analysis to identify the bacterial species. Based on the results obtained from strain＇s screening and identification, antagonism between strains and pathogenic bacteria was researched by dual culture on potato dextrose agar. [Results] Siderophore-producing bacteria HMGY6 B identified as Pseudomonas was isolated and screened out from the ryegrass（Lolium perenne L.） rhizosphere soil, which produced Catechol-type siderophore had the significant effects on cucumber gray mold（Botrytis cinerea）. The inhibition ratio was up to 91.2% under low iron conditions（0.16, 2, 5, 10 μmol/L FeCl3）. But unfortunately, it decreased to 30.2% under 50 μmol/L FeCl3 and only 5.5% under Fe-replete conditions（100 μmol/L FeCl3）. [Conclusion] The srtain HMGY6 B can be used to the exploitation and development of compound disease-resistant manure.