老枞根际放线菌鉴定及其对可可毛色二孢抑制效果研究

Identification and Inhibitory Effect on Lasiodiplodia theobromae of Actinomycetes in Camellia sinensis Rhizosphere Soil

【目的】从老枞根际土壤分离可培养放线菌,获取潜在新物种,并筛选可可毛色二孢菌拮抗菌株。【方法】采用土壤稀释涂布法和三区划线法进行分离和纯化,获得放线菌菌株;通过比对16S rRNA基因序列和构建系统发育树,对菌株进行初步分类和鉴定;采用平板对峙法进行抑菌活性筛选。【结果】(1)共获得81株不同放线菌菌株,分别隶属于链霉菌Streptomyces(54.32%)、节杆菌Arthrobacter(27.16%)、微杆菌Microbacterium(11.11%)、北里孢菌Kitasatospor(4.94%)和短小杆菌Curtobacterium(2.47%)5个属;(2)与已知模式菌株相比,相似度小于98.65%的潜在新种共有20株;(3)经可可毛色二孢平板对峙试验筛选后,获得7株高抑菌活性链霉菌,其中链霉菌ON316885的抑菌率最高,达到63.92%。【结论】武夷山老枞根际土壤中蕴含着丰富的放线菌资源,具有深度挖掘研究的价值,其中一些链霉菌具有较高的生防应用价值。

【Objective】Actinomycetes collected from the rhizosphere soils of old tea plants were isolated to screen for species unknown previously and their potential pathogenic inhibitory effect.【Method】Soil specimens were gathered from the target lots at Shuixian,Fujian to isolate actinomycetes by plate culture.Phylogenetic trees based on 16S rRNA gene for the isolates were constructed and diversity index calculated in the tea plant rhizosphere soils.【Result】(1)Eighty-one actinomycete strains were obtained that belonged to Streptomyces(54.32%),Arthrobacter(27.16%),Microbacterium(11.11%),Kitasatospora(4.94%),and Curtobacterium(2.47%).(2)In comparing with the reference strain,20 of the 81 taxa showed less than 98.65%similarity.(3)Seven strains of the Streptomyces significantly inhibited the growth of Lasiodiplodia theobromae,of which,the one code-named WYS-24 reached the highest rate at 63.92%.【Conclusion】Abundantly diverse actinomycetes resided in the rhizosphere of old tea plants in Wuyishan region.They were a rich resource for in-depth studies and development for biological inhibitors against plant pathogens.