水稻纹枯病生防内生菌糖蜜草固氮螺菌的分离与鉴定

 本文首先对砂仁内生细菌进行分离，以水稻纹枯病菌(Rhizoctonia solani)为靶标菌对获得菌株进行离体拮抗活性、盆栽及田间试验测定。结果表明：获得的27株内生细菌中有4株具有较好的离体抑菌活性，其中SRJ2-4抑菌效果最好，抑菌带达到18 mm；SRJ2-4的盆栽防效及田间防效分别为80.7%与79.4%，与其它菌株相比达极显著水平。SRJ2-4处理的亩产量为488.79 kg，高于其他药剂处理。对该菌株形态、生理生化及16S rDNA序列进行分析，将该内生菌鉴定为糖蜜草固氮螺菌(Azospirillum melinis)。

Isolation and identification of an endophytic bacteria Azospirillum melinis against Rhizoctonia solani

Twenty-seven endophytic bacterial strains isolated from Fructus amomi were tested for in vitro antagonistic activity,pot experiment and field trial against the rice sheath blight pathogen,Rhizoctonia solani.The results revealed that 4 of the 27 isolates showed good anti-fungal activity against Rhizoctonia solani,of which SRJ2-4 exhibited the best effect with an inhibition zone up to 18 mm in diameter.The control efficacy of SRJ2-4 strain in pot experiment and field trial were 80.7% and 79.4% respectively,significantly higher than those of other isolates.The yield of the field treated with SRJ2-4 was also found to be the highest,up to 488.79 kg·667 m-2.According to the morphological analysis,physiological and biochemical determination and 16S rDNA sequence comparison,the strain SRJ2-4 was identified as Azospirillum melinis.