一株拮抗稻瘟病菌的产荧光假单胞杆菌

从稻草茬中分离到的拮抗细菌中，筛选出高效菌株ＪＫＤ－２．无论在稻瘟菌孢子培养基或扩大培养基中，它都具有溶解菌丝体和抑制孢子形成的能力．在土豆培养基中，对多种植物病原菌具有拮抗作用．经电镜观察，培养物性状和生理生化鉴定，可确定该菌为具有荧光的假单胞杆菌属（Ｐｓｅｕｄｏｍｏｎａｓｓｐｐ．）的一个成员．该菌体培养液经氯仿、乙酸乙酯、８０％丙酮水和水分别提取，除８０％的丙酮水外，都能从细菌菌体或培养基中获得对稻瘟菌的拮抗物质．在盆栽试验中，水稻秧苗叶面喷洒ＪＫＤ－２，能抑制稻瘟菌的接种感染，与对照组相比，防治效果可达６０％，差异达到显著程度．该菌经稻草培养基诱导，能分泌一种胞外蛋白，经ＳＤＳ－ＰＡＧＥ分析，相对分子质量约为１３ｋｄ．

Antagonism against Rice Blast Disease and Other Phytopathogens by a Strain of Fluorescent Pseudomonas spp

A strain named JKD 2 was isolated from rice rhizobacteria and it was identified as a member of fluorescent Pseudomonas spp. characterised through EM observation, colony analysis and biochemical determination. This strain could effectively lyse Pyricularia orzyae Canara mycelia, inhibit their growth and spore formation on rice straw powder solid medium. It could also inhibit six other pathogens of agricultural importance with various extents on potato dextrose medium. The antagonistic metabolites are extracted with either ethyl estate or chloroform and partially characterized in three days culture. Being sprayed with this JKD 2, the rice seedling could be successfully protected from infection of Pyricularici orzyae Canara in the pot test, and the protection efficiency could come at 60%, compared with the control one. An extracelluar protein of 13 kd could be induced from JKD 2 on rice straw powder solid medium.