生防菌株SC11的鉴定、定殖及对棉花枯萎病防治效果研究

 通过生物学特性观察和16S rDNA基因序列分析鉴定菌株SC11为壮观链霉菌(Streptomyces spectabilis)。该菌可在棉花根际土壤以及棉花根部长期定殖,30 d的定殖密度分别为1.38×10⁵ CFU/g和2.95×10³ CFU/g。2011年和2012年的大田防治试验显示,SC11菌粉对棉花枯萎病防效分别为42.51%和36.70%,与对照50%多菌灵(WP)的防效相比无显著差异,施用90~150 d的防效分别显著高于多菌灵(P<0.05)。与清水对照相比,田间施用SC11菌粉棉花倒三叶面积显著提高52.6%,籽棉和皮棉产量分别增加21.9%和23.0%(P<0.05)。研究结果表明,壮观链霉菌SC11是一株对棉花枯萎病具有应用前景的生防菌株。

Identification,colonization and disease suppressive effect of strain SC11 against cotton Fusarium wilt

Based on biological property and 16S rDNA sequence anslysis, actinomycetes strain SC11 was identified as Streptomyces spectabilis. Strain SC11 could establish a stable colonization in cotton rhizosphere and cotton root with populations of 1.38×10⁵ CFU/g and 2.95×10³ CFU/g 30 d after sowing, respectively. Field experiments in 2011 and 2012 showed that the powder formula of strain SC11 exhibited control efficacies (CE) of 42.51% and 36.70% against cotton Fusarium wilt, which was as effective as that of the 50% carbendazim (WP). During 90-150 dpi, the CE of the strain SC11 was significantly higher than that of the carbendazim treatment control (P<0.05). The area of the top 3 leaves treated by the SC11 increased by 52.6% compared with the water treated control, and the yields of seed cotton and ginned cotton increased 21.9% and 23.0% (P<0.05), respectively. Results of above research suggest that the strain SC11 has a potential biocontrol ability against cotton Fusarium wilt.