Cohen Yigal
Faculty of Life Sciences, Bar Ilan University, Ramat Gan 5290002, Israel.
J Fungi (Basel). 2024 Aug 4;10(8):549. doi: 10.3390/jof10080549.
Late blight, caused by the oomycete , is a devastating disease of potato worldwide. In Israel, potatoes are grown twice a year, in autumn and spring, with late blight causing extensive damage in both seasons. While tuber seeds for the autumn planting are produced locally, seed tubers for the spring planting are imported from Europe due to dormancy of local tubers. Here, we demonstrate that seed tubers imported from Europe for the spring season carry asymptomatic infection with EU genotypes of , which alters the population structure of the pathogen each spring. The proportion of imported tubers carrying asymptomatic infections ranged between 1.2 and 3.75%, varying by year and cultivar. Asymptomatic tubers produced late blight-infected sprouts about one month after planting. The sporangia produced on these sprouts served as primary inoculum, causing intensive foliage attacks on neighboring plants. When sprout-infected plants were uprooted and the mother tuber was washed, sliced, and placed in moistened dishes at 18 °C, profuse sporulation of developed on the slices' surfaces within 1-2 days. The dominant genotype of in the autumn season in Israel is 23A1, but genotypes in the following spring season changed to include 13A2 or 36A2. Surprisingly, genotype 43A1, which might be resistant to CAA and OSBPI fungicides and appeared in Europe in 2022, emerged in Israel in spring 2024. The immigrating genotypes do not persist in the country, allowing 23A1 to regain predominance in the following autumn. Long-term monitoring data suggest that the population structure of changes yearly but temporarily due to the import of new genotypes from Europe.
由卵菌引起的晚疫病是全球马铃薯的一种毁灭性病害。在以色列，马铃薯一年种植两季，分别在秋季和春季，晚疫病在两个季节都会造成广泛损害。秋季种植的块茎种子在当地生产，而春季种植的种薯由于当地块茎的休眠而从欧洲进口。在此，我们证明，春季从欧洲进口的种薯携带了欧盟基因型的无症状感染，这改变了每年春季病原体的种群结构。携带无症状感染的进口种薯比例在1.2%至3.75%之间，因年份和品种而异。无症状块茎在种植后约一个月产生晚疫病感染的芽。这些芽上产生的孢子囊作为初次接种体，对邻近植物的叶片造成严重侵害。当芽感染的植株被连根拔起，母薯被清洗、切片并放置在18°C的湿润培养皿中时，1-2天内切片表面就会大量产生孢子。以色列秋季晚疫病菌的优势基因型是23A1，但次年春季的基因型变为包括13A2或36A2。令人惊讶的是，可能对CAA和OSBPI杀菌剂具有抗性且于2022年在欧洲出现的基因型43A1，于2024年春季在以色列出现。迁入的基因型在该国不会持续存在，使得23A1在次年秋季重新占据主导地位。长期监测数据表明，由于从欧洲进口新的基因型，晚疫病菌的种群结构每年都会发生变化，但只是暂时的。
