湖南猕猴桃溃疡病致病菌的鉴定及植物源防治药剂的筛选

Identification of pathogenic bacteria of kiwifruit canker in Hunan and evaluation of botanical bactericides

为了能够有效且无污染地防控猕猴桃溃疡病,提高猕猴桃果实质量和安全水平,减少溃疡病对猕猴桃果园带来的危害,本研究从猕猴桃溃疡病的病组织中分离出病原物分离物,通过柯赫氏法则,结合分离物的形态学观察和分子鉴定,确定猕猴桃溃疡病的病原菌;利用80种中药植物提取液通过牛津杯法测定其对病原菌的抑制效果,从中选出抑菌效果强的中药植物提取液。经鉴定,湖南猕猴桃溃疡病主要致病菌为丁香假单胞杆菌(Pseudomonas syringae)。黄芩、丁香、石菖蒲和广藿香4种中药的丙酮提取物对猕猴桃溃疡病菌的抑菌圈直径都在20 mm以上,有较好的抑菌效果。其中,黄芩的抑菌效果最好,最低抑菌浓度仅为3.90 mg/mL。部分中药提取液对丁香假单胞杆菌具有一定的抑制作用,且含有大量黄酮或精油类的中药提取液抑菌效果更好。

In order to control kiwifruit canker disease effectively and pollution-freely,improve the quality and safety level of kiwifruit,and reduce the harm of canker disease on kiwifruit orchard,the pathogen isolates isolated from canker tissue of kiwifruit were determined by Koch’s rule combining with morphological observation and molecular identification. Eighty kinds of Chinese medicinal herbal extracts were evaluated for their inhibitory effect on pathogenic bacteria by Oxford cup method,and the Chinese medicinal herbal extracts with strong antibacterial effect were selected. The main pathogen of kiwifruit canker in Hunan was Pseudomonas syringae. Acetone extracts of Scutellaria baicalensis,Syzygium aromaticum,Acorus tatarinowiiz and Pogostemon cablin all showed good antibacterial effect against kiwi ulcer bacteria with diameter more than 20 mm. Scutellaria baicalensis had the best antibacterial effect,and the minimum inhibitory concentration was as low as 3.90 mg/mL. Some extracts of traditional Chinese medicine have certain inhibitory effect on Pseudomonas syringae,and the traditional Chinese medicine extracts which contain a lot of flavonoids or essential oils would have better antibacterial effect.