水稻纹枯病生防内生菌糖蜜草固氮螺菌的分离与鉴定

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

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)。

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 SRJ24 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 SILl24 was also found to he 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 SRJ24 was identified as Azospirillum melinis.