海南飞机草病原真菌鉴定、致病力测定及其寄主范围分析

Identification, Virulence and Host Range Analysis of Pathogenic Fungi of Chromolaena odorata in Hainan

对海南多个市县的飞机草发病情况进行调研发现,飞机草叶斑病受自然环境及病菌种类的影响,从发病样品上分离获得46株病原真菌。经过形态学观察与分子鉴定比对,确定飞机草的重要病原真菌分别为:链格孢Alternaria alternata、新月弯孢Curvularia lunata和尖孢镰刀菌Fusarium oxysporu。通过离体叶片针刺法和活体接种法对病源真菌致病力进行测定,结果显示,强致病力菌株12个(占26.09%),中等致病力菌株13个(占28.26%),弱致病力菌株19个(占41.30%),无致病力菌株2个(占4.3%),其中链格孢菌株LGB100501、LGB100401和弯孢菌株WB110216表现出较高的致病力。利用11个高致病力菌株针对8种海南常见杂草进行寄主范围测试,结果表明,不同菌株致病力存在差异,仅有13.6%的供试杂草对这些菌株表现出高度和中度感病。

The investigation and sampling of the infection situation of Chromolaena odorata in some regions of hainan revealed that the leaf spot was influenced by natural environment. 46 pathogenic fungi were isolated. Based on morphological characteristics and sequence alignments of rDNA ITS region, the most important pathogen fungi of C. odorata were identified as Alternaria alternata, Curvularia lunata and Fusarium oxysporu. The virulence of the strains were determined by inoculation in vitro and in vivo. The results showed that the high-pathogenic strains were 12（26.09%）, the medium-pathogenic were 13（28.26%）, the low-pathogenic were 19（41.30%）, and non-pathogenic 2（4.3% ）. The virulence of LGB100501, LGB100401 and WBLI0216 were very high. High virulence of 11 strains to 8 weeds showed that different strains had differences in virulence, highly susceptible and moderately susceptible accounted for only 13.6%.