Identification and field control efficacy of endophytic bacterial strain Jaas cd against cotton Verticillium wilt.

An endophytic bacteria against cotton Verticillium wilt,strain Jaas cd(original name 73a),was identified and its application methods in the field were improved.The strain showed the strong antifungal activity against 12 fungal pathogens including Verticillium dahliae Kleb,Fusarium oxysporum f.sp.vasinfectum,Fusarium moniliforme and Rhizoctonia solani.According to the morphological and physiological characteristics,Biolog identification and phylogenetic analysis,strain Jaas cd was identified as Paenibacillus polymyxa.The sequence data containing 1 436 bp for the 16S rDNA gene of the strain Jaas cd has been deposited in GenBank with the accession number: AY942618.The 16S rDNA sequence similarity of 99.7% was observed between strain Jaas cd and Paenibacillus polymyxa(GenBank accession number: AM062684).The results of field trial showed that the disease indexes of cotton Verticillium wilt were decreased and the yields of cotton were increased by both spraying the culture liquid of strain Jaas cd to cotton seeding beds before transplantation and watering seedling roots after transplantation.Spraying the culture liquid of strain Jaas cd to the cotton seeding bed before transplantation was more convenient to operate than watering the seedling roots after transplantation.