珠芽蓼内生菌Z5产IAA和抑菌能力测定及其鉴定

以珠芽蓼内生细菌Z5为研究对象,采用Salkowski比色法和平板对峙法测定其分泌植物生长素(IAA)的能力和对病原真菌的抑菌能力;并利用16SrDNA序列分析结合生理生化特征对Z5进行了鉴定。结果表明,Z5在含有色氨酸和不含色氨酸的King培养基中分泌IAA分别为68.62和5.14mg/L;Z5对番茄灰霉病菌、小麦离蠕孢菌、玉米大斑病菌、油菜菌核病菌、番茄早疫病菌、辣椒立枯丝核病菌、甜瓜枯萎病菌7种病原真菌有抑制作用,说明Z5具有较广的抑菌谱。Z5菌体杆状,大小为1.65～3.34μm×0.46～0.71μm,G⁺,中生芽孢,生理生化特性和16SrDNA基因序列测试结果均表明,Z5为枯草芽孢杆菌(Bacillussubtilis)。本研究为高寒草地特有的植物内生促生拮抗菌的开发和利用提供依据,也为开发经济环保的生物农药提供菌种资源。

Identification of Polygonum viviparum endophytic bacteria Z5 and determination of thecapacity to secrete IAA and antagonistic capacity towards pathogenic fungi

The study is focused on Polygonum viviparum endophytic bacteria Z5. Salkowski colorimetric determination and confronting cultivation on PDA plates experiment have been used to determine the capacity of Z5 to secrete IAA and Antibacterial spectrum of Pathogenic fungi of Z5. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis have also been used to identify Z5. The results showed that the concentration of IAA secreted by Z5 in the medium containing 100 mg/L tryptophan King is 68.62 mg/L, and the concentration of the one without tryptophan King is 5.14 mg/L. Z5 can inhibit Pathogenic fungi, such as Rhizoctonia solani, Sclerotinia sclerotiorum (rape strain), Alternaria solani, Botrytis cinerea, Exserohilum turcicum, Bipolaris sorokiniana, Fusarium oxysporum f.sp.melonis, showing that Z5 has a wider Antibacterial spectrum. Z5 is Rod-shaped with a size of 1.65-3.34 μm × 0.46-0.71 μm, Gram-positive, and can produce spore in the center. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis show that Z5 is Bacillus subtilis. The study will provide evidences for the exploration and utilization of promoting growth and Antibacterial endophytic bacteria in alpine meadow and it will also provide strain resource for making economical and environment-friendly Biopesticides.