苜蓿链霉菌TX21抑菌作用确定及促生物质的鉴定

Inhibition of Streptomyces alfalfae TX21 on Pathogenic Fungi and Identification of Its Growth-promoting Substances

链霉菌是一种重要的微生物资源,具有广泛的应用价值。本研究从土壤中筛选出一株对多种病原菌有抑制效果的菌株,编号TX21,其中对玉蜀黍平脐蠕孢的抑菌效果最优,为50.0%。采用浸种及喷施的方法探究了菌株TX21发酵上清液对水稻种子和黄瓜幼苗的促生效果,结果显示发酵上清液能使水稻种子胚根和胚芽分别增长48.5%和47.1%,黄瓜幼苗根系和鲜重分别增加了37.6%和47.0%,表现出良好的促生作用;通过形态学观察、生理生化和16S r RNA分子生物学鉴定苜蓿链霉菌Streptomyces alfalfae。利用黄瓜子叶叶绿素试验及UHPLC-MS方法明确了发酵上清液的有效促生物质,证实其中含有2-甲硫顺式玉米素核苷(ms^(2)io^(6)A,分子式:C_(16)H_(23)N_(5)O_(5)S)。

Streptomyces is an important microbial resource with extensive application value.In this study,a strain with inhibitory effect on a variety of plant pathogen was isolated from soil,numbered TX21.It showed the highest inhibition rate of 50.0%against Bipolaris zeicola.The growth promoting effect of strain TX21 culture filtrate on rice seeds and cucumber seedlings was investigated by seed soaking and spraying.The results showed that the culture filtrate could significantly increase the growth of radicle and germ of rice seeds by 48.5%and 47.1%,respectively.For cucumber seedlings,it increased root length by 37.6%and fresh weight by 47.0%.These findings demonstrated the excellent growth-promoting effect of culture filtrate.The strain was preliminarily identified as Streptomyces alfalfae by morphological observation,physiological and biochemical identification and 16S rRNA molecular biology.The effective biomass promoting activity of the culture filtrate was identified by chlorophyll assay of cucumber cotyledon and UHPLC-MS,and 2-methylthio-cis-ribozeatin(ms^(2)io^(6)A,chemical formula:C_(16)H_(23)N_(5)O_(5)S)was found in the culture filtrate.