寒地耐冷生防菌株筛选鉴定及特性研究

Study on isolation and characterization of a psychrotrophic antagonistic bacterium from cold area

试验分离鉴定黑龙江省鹤岗地区玉米根围冻土中生防菌株wswshg^(-1)0,并检测其低温生长特性、分泌活性物质能力、拮抗病原菌活性及催芽促生特性。综合形态和理化特性、16S r DNA和gyr B基因序列分析将其鉴定为甲基营养型芽孢杆菌Bacillus me thylotrophicus。该菌株在4~15℃低温及20~30℃常温范围内可正常生长,是一株耐冷生防菌株,分泌几丁质酶、纤维素酶、蛋白酶、嗜铁素、吲哚乙酸、抗菌蛋白等多种活性物质,抑制烟草角斑病菌、玉米茎基腐病菌、黄瓜枯萎病菌、大豆菌核病菌、水稻恶苗和稻曲病菌、番茄灰霉病菌以及刺五加根腐病菌生长,抑制率74.3%~89.2%。菌液处理玉米种子能促进种子萌发及幼苗生长,根长和茎长显著增加。该菌株具有低温生长、抗菌促生特性,为低温菌剂研发提供菌株资源。

A psychrotrophic antagonistic bacterium wswshg10 was isolated from maize rhizospheric frozen soil in Hegang area, Heilongjiang Province. Based on morphology and biochemistry characterization as well as 16 S r DNA and gyr B gene sequence analysis, strain wswshg-（-1）0 was identified as Bacillus methylotrophicus. The strain exhibited a capability of growth at low temperature ranged from 4 to 15 ℃ and at normal temperature ranged from 20 to 30 ℃, secreting chitinase, cellulase, protease, siderophore,indoleacetic acid and antifungal proteins. It was able to inhibit pathogen growth such as Pseudomonas syringae, Sclerotinia sclerotiorum, Fusarium moniliforme, Ustilaginoidea oryzae, Fusarium oxysporum,Fusarium graminearum, Rhizoctonia solani, Botrytis cinerea and Pythium spp., the rate of inhibition was74.3%-89.2%. Soaking seed revealed that the strain could promote maize seed germination and seedling growth. Stain wswshg-10 had multifaceted beneficial characteristics. It may be an ideal plant growth promoting and biocontrol agent for its integrated use in agriculture.