野生大豆内生真菌YD09鉴定及促生耐盐特性研究

Identification of Endophytic Fungi YD09 from Wild Soybean and Its Characteristics in Promoting Growth and Salt Tolerance

为从野生大豆中筛选具有促生抗逆的内生菌,利用组织分离法从野生大豆根中分离内生真菌,根据菌株形态和ITS序列系统发育树对菌株进行鉴定,研究菌株自身耐盐特性、胞内和胞外产物对大豆幼苗生长及耐盐性的影响。结果显示:分离得到1株内生真菌,基于菌株形态学和rRNA基因ITS序列系统发育分析,鉴定为交链孢霉菌(Alternaria alternata),命名为YD09。菌株YD09耐NaCl浓度可达30%。菌株YD09作用于大豆幼苗,具有良好的促生效果,且可使幼苗耐NaCl浓度达到200 mmol·L^(-1)。菌株YD09胞内产物对大豆幼苗具有明显的促生效果,胞外产物能提高大豆幼苗对盐胁迫的抗性。综上,菌株YD09具有较好的促生、耐盐能力,能够缓解盐胁迫对大豆幼苗的伤害,可作为农业生产上应用的新菌种资源。

In order to screen endophytes with growth promotion and stress resistance from wild soybeans,we used tissue separation method to isolate endophytic fungi from wild soybean roots.The strain was identified according to the morphology and ITS sequence phylogenetic tree.The salt tolerance characteristics of the strain itself was studied,as well as the effects of intracellular and extracellular products on the growth and salt tolerance of soybean seedlings.One endophytic fungus was isolated and identified as Alternaria angustifolia,which was named YD09.The strain YD09 can grow up under 30%NaCl concentration.Strain YD09 has a good promoting effect on soybean seedlings,and make the seedlings resistant to NaCl concentration up to 200 mmol·L^(-1).The intracellular product of strain YD09 has a significant resistance promoting effect on soybean seedlings,extracellular products can enhance salt tolerance of soybean seedlings.Strain YD09 has good growth promoting and salt tolerance abilities,which can alleviate the damage of salt stress to soybean seedlings,and it can be used as a new strain resource in agricultural production.