致病疫霉拮抗细菌SR13-2菌株的鉴定及对马铃薯离体组织的防病作用

Identification of SR13-2 Strain against Phytophthora infestans and Control of Late Blight on Detached Potato Tissues

SR13-2菌株是前期从种植莴苣的土壤中分离获得的对致病疫霉菌丝生长和孢子萌发有强烈抑制作用的拮抗细菌,为进一步了解其生物学特性以及防治马铃薯晚疫病的潜力,本试验依据其培养特征、生理生化特性及16S r DNA序列对该菌株进行了鉴定,并测试了其菌液在离体马铃薯组织上的防病效果。结果显示该菌株属于深红沙雷氏菌(Serratia rubidaea),菌液在马铃薯块茎切片上对晚疫病的预防效果可达91.83%,治疗效果可达83.33%,显著优于甲霜灵锰锌以及其他几株拮抗细菌,在马铃薯离体叶片上也获得了相似的结果。这表明SR13-2菌株在马铃薯晚疫病防治方面有较大潜力。

Bacterial SR13-2 strain which strongly inhibited mycelial growth and spore germination of Phytophthora infestans was obtained in earlier experiment in our lab. In order to further understand its biological characteristics and potential in controlling potato late blight, the taxonomic status of this stain was identified, and control efficiency on potato tuber slices and detached leaves were detected in this experiment. The results showed that SR13-2 strain was identified as Serratia rubidaea based on cultural features, thallus morphology, gram staining, spore staining, physiological and biochemical characteristics, as well as 16S rDNA sequences. The prevention efficiency and therapy efficiency of bacterial fluid of this strain on potato tuber slices were 91.83% and 83.33%, respectively, which were significantly better than treatments of Ridomil-MZ and other antagonistic bacteria. Similar results were also obtained on detached potato leaves. These results indicated that SR13-2 strain has a great potential in controlling potato late blight in future.