甘肃省马铃薯枯萎病(Fusarium avenaceum)鉴定及其病原生物学特性

Identification of potato wilt caused by Fusarium avenaceum and the biological characteristics of its pathogen

对甘肃省马铃薯枯萎病菌进行了分离、鉴定及培养特性的研究.结果表明,该病原菌大型分生孢子镰刀形,无色,多细胞,大小为（12.5～30）μm×（2.5～5）μm;小型分生孢子数量较多,无色,卵圆形或椭圆形,大小为（4.70～12.94）μm× （1.76～2.35）μm; ITS序列分析表明,病原菌与Fusarium avenaceum （JN6317483）亲缘关系最近,相似性达到100％,结合形态特征鉴定该病原菌为燕麦镰刀菌（Fusarium avenaceum）.该病原菌在5～40℃范围内均可生长,最适温度为20℃;供试的碳、氮源中,果糖和亮氨酸对该菌菌丝生长有显著的促进作用（P＜0.05）,而显著抑制菌丝生长的是氯醛糖和碳酸铵（P＜0.05）;不同类型培养基中,燕麦片培养基对菌丝生长有显著促进作用（P＜0.05）.

The pathogen causing potato wilt were isolated and identified by the rDNA-ITS sequences and biological characteristics in Gansu Province. The results showed that the macroconidia were hyaline, sickle-shaped, multi- cellular, and the size was （12.5 30）μm × （2.5--5）μm. The microconidia were oval, and the size was （4.70- 12.94） μm× （1.76 2.35）μm. The rDNA-ITS sequence of the pathogenic fungus shared 100% similarity with that of Fusarium avenaceum （JN6317483）. The morphologic characteristics and ITS sequence analysis all indicated that the pathogenic fungus was F. avenaceum. The suitable culture temperature was from 5 ℃ to 40℃, and the optimum was 20 ℃. D-fructose and leucine had significant promoting effect on the growth of the mycelia （P〈0. 05）, and chloralose and ammonium carbonate significantly inhibited mycelial growth （P〈0. 05）. Oatmeal me- dium played a significant role in promoting myeelial growth （P〈0. 05）.