松苗根际生防菌的研究

Study on biocontrol bacteria strain of pine seedling rhizosphere

采用平皿稀释分离法,通过对320株湿地松根际细菌分离物的筛选,获得1株拮抗性强的细菌菌株;运用16S rDNA序列分析方法,对菌株进行了分子鉴定,结果为洋葱伯克霍尔德菌(Burkholderia cepacia)。以镰刀菌属(Fusarium)、丝核菌属(Rhizoctonia)、链格孢菌属(Alternaria)的真菌为病原菌,该菌株和生防菌株Pseudomonas fluorescens Q2-87、2-79、1M1-96、Pf-5、HT5-1、Q37-87、MVP1-4、FFL1R8共同对病原菌的平皿对峙试验,该菌株对立枯丝核菌、链格孢菌都有较强的拮抗作用,120 d盆栽测试得知,菌株P.fluorescens Q2-87最高保存率为77%,该菌株的最高保存率为62%,其拮抗效果和菌株Q2-87一样,均高于其他7个生防菌株,试验证明该菌株具有防治松苗猝倒病的潜力。

One strong antagonistic bacterial strain was gained by screening 320 bacterial isolates from the slash pine rhizo- sphere using the dilution plate method; This strain was identified as Burkholderia cepacia through the molecular identification using the method of 16S ribosomal DNA sequence analysis. Using Fusarium, Rhizoctonia and Alternaria as the pathogens,in vitro inhibition tests of this strain and biocontrol bacteria Pseudomonas fluorescens Q2- 87, 2- 79, 1M1 -96, Pf- 5, HT5 - 1, Q37- 87, MVP1 -4, FFL1R8 show that this strain has strong antagonistic ability against Rhizoctonia and Alternaria; The pot experiment in 120 days showed that the survival rates of the seedlings treated by Q2 - 87 is 77% , that treated by this strain is 62%, the control is 38% , and the inhibition ability of this strain is the same as that of Q2 - 87 and higher than that of the other 7 strains. In a word, this strain has the potential of controlling the pine seedling damping off.