河北省西瓜枯萎病菌形态比较和致病力测定

Morphology comparison and determination of the pathogenicity of Fusarium oxysporum f.sp. niveum in Hebei

对从河北省西瓜种植区采集到的西瓜枯萎病病株进行病菌的分离培养 ,获得了 38株西瓜枯萎病菌菌株。通过在PSA培养基上培养和观察 ,发现以菌落形态特征为依据 ,可将供试菌株大体分成三类 :Ⅰ类 ,气生菌丝呈白色绒状 ,菌落颜色为白、淡紫、紫色 ;Ⅱ类 ,气生菌丝呈白色絮状 ,菌落颜色多为淡紫色 ;Ⅲ类 ,气生菌丝不发达 ,菌落颜色为白色、淡紫色。以中等抗性的西瓜品种“Crimsonsweet”为寄主进行致病力测定 ,结果表明不同菌系的致病力差异达到了极显著水平 ,致病力最强的是来自隆尧的FON3菌株 ,其次是来自望都的FON15菌株 ,最弱的是来自大名和平乡的FON10和FON12。

Thirty-eight isolates of Fusarium oxysporum f.sp. niveum were isolated from diseased watermelon in different regions of Hebei.The colony characteristics were observed on PSA medium. Depending on the colony morphology, the isolates were divided into three groups.I, the aerial hyphae of the first group were white and villiform with the colony of white, light violet or violet color. II,the aerial hyphae were white wadding with colonies light violet color. III, the aerial hyphae was not well developed and the color of colonies were white or light violet.“Crimson sweet” with middle resistance to F.oxysporum f.sp. niveum was selected as the host to test pathogenicity. The result indicated that the pathogenicity was significantly different among the isolates. Isolate FON3 from Longyao had the heightest toxicity to the cultivar tested and isolate FON10, FON12 from Daming and Pingxiang, respectively, had the lowest toxicity.