花生网斑病原菌孢子差异及其致病力分析

花生网斑病（peanut web blotch）,由花生亚隔孢壳菌（Didymella arachidicola）引起,病原菌又称花生茎点霉（Phoma arachidicola）或派伦霉（Peyronella arachidicola）,在我国南北的各大花生产区均有发生,已成为生产上严重的叶部病害。为筛选产孢效率高、致病力强的菌株,研究病原菌进化机制和环境适应性,从来自不同地区的花生网斑病叶片样本中分离病原菌菌株,研究分生孢子及致病力差异。结果表明,18个菌株中YY187的产孢时间最短,22℃黑暗条件下燕麦琼脂培养基培养7 d即可产孢;菌株YY187和NY206产生的分生孢子器数量显著多于其它菌株;采用孢子悬浮液接种花生叶片,供试所有菌株均可造成叶片发病,其中菌株LY128和YY187在供试18个菌株中致病力相对较强。因此,综合评价产孢效率更高、致病力更强的本地菌株YY187适合作为花生抗网斑病研究的材料。

Differences in conidia of peanut web blotch pathogen and its pathogenicity analysis

Peanut web blotch, caused by Didymella arachidicola （also known as Phoma arachidicola or Peyronella arachidicola）, is occurring in all major peanut-producing regions. It becomes one of the most challenging leaf diseases of peanut in China currently. To identify the strains for resistant peanut breeding, pathogens were isolated from peanuts from different regions. Results indicated that isolate YY187 showed the shortest sporulation duration. The YY187 strain produced conidia after 7 d on oatmeal agar medium under dark condition of 22°C. Moreover, isolates YY187 and NY206 produced significantly more pycnidia than others. By inoculating peanut leaves with spore suspension, all the 18 tested isolates led to leaf disease, among which LY128 and YY187 had relatively strong pathogenicity. According to comprehensive evaluation, YY187 performed higher sporulation efficiency and stronger pathogenicity which makes it an appropriate model isolate for further studies of peanut web blotch.