具有ACC脱氨酶活性及抗枯萎病菌的假单胞菌株B*8

运用新的快速筛选程序，获得了具有１－氨基环丙烷－１－羧酸（１－ａｍｉｎｏｃｙｃｌｏｐｒｏｐａｎｅ－１ｃａｒ－ｂｏｘｙｌａｔｅ，ＡＣＣ）脱氨酶活性和拮抗瓜类枯萎病菌双重功能的根际假单胞菌株Ｂ８．利用ＡＣＣ为唯一氮源，从不同的土样中，快速筛选出８０个具有ＡＣＣ脱氨酶活性的菌落．在马铃薯葡萄糖培养基和西瓜培养基上，经异步培养法进一步筛选并纯化出３株对西瓜枯萎病菌具有较强拮抗作用的拮抗菌Ａ９、Ｂ８和Ｃ１７．对拮抗作用最强的Ｂ８进行分析表明，它属于假单孢菌属，能分泌较多的铁载体，对瓜类枯萎病以及其他植物病原菌具有广谱抗性．结果显示，此程序可替代通常采用的低效而耗时的筛选和生物测定过程，加快新的促进植物生长根际细菌的筛选和应用．

Quickly Screening a Strain of Pseudomonas B8 with both ACC Deaminase Activity and Antagonism Against Fusarium Oxysporum

Using 1 aminocyclopropane 1 carboxylate (ACC)as a sole nitrogen source,80 plant growth promoting rhizobacteria(PGPR) were quickly selected from 3 different soil samples.And 3 strains antagontisic against Fusarium oxysporum were further selected from these PGPR with the method of step differential cultivation on WSA and PDA medium.These 3 strains were named A 9,B 8 and C 17 respectively.B 8 has shown the strongest antagonism against Fusarium oxysporum among the 3 strains. The further analyses indicate that B 8 belongs to a member of Pseudomonas spp .It could antagonize many other phytopathogens and excrete much more siderophore than others.The result demonstrates that this procedure can replace the low efficiency,time consuming procedures and bioassay for PGPR screening and identification and fast the screen and application of PGPR in agriculture.