杨树湿心材致病细菌及其拮抗细菌的鉴定

为分离并鉴定杨树湿心材病的主要致病细菌与其拮抗细菌，从不同杨树无性系发病组织中分离、纯化出优势菌株，分别回接实生苗进行致病性测定与病原菌鉴别；并进行形态学、生理生化特征、脂肪酸、16SrRNA基因序列以及多基因序列分析。结果表明：分离纯化得到了10株优势菌株, 回接实验发现12-1菌株能导致杨树出现湿心材症状，鉴定其为杨柳欧文氏菌；从杨树心材中分离出了18个内生菌，通过拮抗菌筛选，发现J-4能有效抑制12-1菌株对杨树造成的湿心材现象，鉴定为类芽孢杆菌。因此，杨柳欧文氏菌是杨树湿心材病的主要致病菌，类芽孢杆菌是其拮抗菌。

Identification of Pathogen Bacteria and Antagonistic Bacteria of Wet-heart Wood Disease in Populus

In order to separate and purify the main pathogen bacteria to wet-heartwood disease in Populus and the correspondent antagonist bacteria, dominant strains were separated and purified from pathogenic tissues of different Populus varieties, then tested the pathogenicities by inoculation to sterile Populus seedlings. The pathogen and correspondent antagonist bacteria were classified and identified by morphology, physiological-biochemical characteristics, fatty acid composition analysis, 16SrRNA sequence and MLSA. The results show that 10 dominant strains are separated and purified, and pathogen 12-1 caused evident symptom after inoculation to sterile poplar seedlings, and it is classified and identified as Brenneria salicis; Eighteen endogenous strains are isolated from the stem of Populus trees, of which J-4 isolate is selected and verified as antagonist bacteria of the pathogen bacteria strain 12-1 by the confrontation culture and the inoculation in Populus sterile seedlings, and it is preliminary determined to be Paenibacillus taiwanensis. In conclusion, Brenneria salicis is the main pathogen to wet-heartwood disease in Populus, and Paenibacillus taiwanensis ias the correspondent antagonist bacteria.