宁夏南部山区马铃薯晚疫病菌寄生适合度测定

Parasitic fitness of Phytophthora infestans isolated from southern regions of Ningxia

为了解宁夏南部山区马铃薯主栽品种对马铃薯晚疫病菌的抗病性情况,明确不同菌株的寄生适合度,采用离体叶片接种法,用4个马铃薯品种对采自宁夏南部山区的5个马铃薯晚疫病菌分离株进行了侵染率、病斑面积、产孢能力的测定和寄生适合度的计算。结果表明,‘克新18号’对供试的晚疫病菌分离株具有较高的抗病性,其次为‘中薯3号’和‘克新1号’,‘费乌瑞它’的抗病性最差;来源于固原原州区的分离株(GL2和GL7)寄生适合度较高,来源于泾源县的分离株(JZ)寄生适合度较弱。采自宁夏不同地区的晚疫病菌分离株对同一马铃薯品种的寄生适合度有较大差异,同一晚疫病菌株在不同马铃薯品种上的寄生适合度也有一定的差异,表明宁夏南部山区马铃薯晚疫病菌分离株存在一定的致病性分化。

In order to understand the main potato cultivars resistance to Phytophthora infestans and the parasitic fitness of cfifferent causal fungal isolates, the infection frequency, lesion size, and sporulation capacity of five P. infestans isolates from potato in the southern regions of Ningxia were tested using four potato cultivars on the detached leaflets. The results showed that the cultivar ＇Kexin 18＇ had the strongest resistance to the tested isolates, and ＇Zhongshu 3＇ and ＇Kexin 1＇ took the second place, while ＇Favorita＇ was the susceptible cultivar to the tested isolates. The result of calculated parasitic fitness revealed that the isolate GL2 and GL7 from Yuanzhou District of Guyuan City had the highest parasitic fitness, and the isolate JZ from Jingyuan County had the lowest fitness. In summary, the tested P. infestans isolates from southern regions of Ningxia had different parasitic fitness on the same cultivar, and the single isolate has different parasitic fitness on the same cultivar, indicating that the pathogenic differentiation exists to some degree among P. infestans isolates in the southern regions of Ningxia.