摘要
通过分离青海高寒草地针茅根际土壤细菌,以番茄早疫病菌、马铃薯枯萎病菌、马铃薯坏疽病菌和马铃薯炭疽病菌为指示菌,采用平板对峙法对其拮抗功能进行评价,并利用16SrDNA序列分析法进行鉴定。结果表明,从针茅根际土壤中共分离获得23株土壤细菌,17株可转代培养,根际土壤细菌数量介于6.4×10^6~36×10^6cfu·g^-1,其中4T1、5T1、10T1和10T3至少对1种病原真菌有抑菌作用,占细菌总数的17.39%,抑菌率介于46.68%~75.71%;菌株10T1的抑菌效果最好,对番茄早疫病菌、马铃薯枯萎病菌、马铃薯坏疽病菌和马铃薯炭疽病菌的抑菌率分别为67.14%、68.57%、61.43%和75.71%;23株土壤细菌均呈革兰氏阳性,杆状,大小介于3.79μm×0.85μm^10.50μm×2.37μm。结合培养形状、形态特征和16SrDNA序列分析将17株土壤细菌鉴定为7属12种,其中芽孢杆菌属8株,占鉴定总数的47.05%,为优势属。通过对青海高寒极端生境针茅根际土壤细菌的拮抗功能评价,为生防菌剂的开发提供了菌株资源。
Soil bacteria were isolated from the rhizosphere of Stipa plants in alpine grassland of Qinghai province,China.Antifungal activity of the isolated bacteria was determined using the plate confrontation method for Alternaria solani,Fusarium avenaceum,Phoma foveata and Colletotrichum coccodes,and the bacteria were identified by 16S rDNA sequence analysis.The results showed that 23 strains of bacteria were isolated,and 17 of these strains could be sub-cultured.The soil bacteria count was between 6.4×10^6 and 36×10^6 cfu·g^-1.Four bacterial strains(17.39%of isolated taxa)designated 4T1,5T1,10T1 and 10T3 had an antagonistic effect on more than one tested fungus,and the degree of inhibition was between 46.68%and 75.71%.Strain 10T1 had a notably strong antifungal effect,with the inhibition levels to A.solani,F.avenaceum,P.foveata and C.coccodes being 67.14%,68.57%,61.43%and 75.71%,respectively.The size of this strain ranged between 3.79μm×0.85μm and 10.50μm×2.37μm and the organism is Gram-positive,and rod-shaped.Combining information about culture characteristics,morphological characteristics and 16S rDNA sequence analysis,the 17 strains of soil bacteria isolated were identified as belonging to 7 genera and 12 species,of which Bacillus was the dominant genus.Of the strains isolated,8 strains(47.05%of isolated strains),were identified as Bacillus.In summary,several isolated soil bacteria from the rhizosphere of Stipa plants in the alpine grassland of Qinghai,displayed significant antifungal activity and could potentially provide microbial resources for the development of biocontrol agents.
作者
刘雪儿
马金凤
杨成德
李统华
LIU Xue-er;MA Jin-feng;YANG Cheng-de;LI Tong-hua(College of Plant Protection,Gansu Agricultural University,Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province,Lanzhou 730070,China)
出处
《草业学报》
CSCD
北大核心
2019年第8期161-169,共9页
Acta Prataculturae Sinica
基金
国家自然科学基金(31660148和31160122)资助
关键词
高寒草地
根际土壤细菌
筛选
拮抗功能
鉴定
alpine grassland
soil bacteria of rhizosphere
screening
antagonistic function
identification