Alnajar Dima, von Tiedemann Andreas, Koopmann Birger
Plant Pathology and Crop Protection, University of Goettingen, 37077 Goettingen, Germany.
Pathogens. 2022 Apr 12;11(4):461. doi: 10.3390/pathogens11040461.
is one of the major pathogens of oilseed rape (). It causes blackleg disease, which accounts for significant yield losses worldwide. Using cultivars that harbor major resistance () genes is one of the most effective control methods. However, the efficacy of major genes is related to the frequency of the corresponding avirulence () genes in a population. In this paper, we report the profiles of populations and the ratio of its mating types in Northern and Central regions of Germany. Eleven genes in five-hundred and seventy-four isolates were characterized either by applying cotyledon tests on a differential set or by amplifying avirulence gene-specific PCR markers. Fifty-two races were determined, among which the most dominant race was . Results showed that the resistance gene is 100% ineffective, some other major genes such as , and are partially effective (with corresponding frequencies ≤ 42%), while , , , and can still provide relatively effective resistance in the German fields investigated (with corresponding frequencies of 63-100%). Sexual reproduction is a factor that enhances the potential of to evolve under selection pressure. Mating types of the populations did not deviate from the ratio of 1:1 in the examined regions, indicating that sexual reproduction and ascospores play central roles in the lifecycle. Overall, this study provides an important dataset for the establishment of a strategic plan to preserve the efficacies of major genes in Germany by applying cultivar rotations of oilseed rape.
是油菜的主要病原菌之一。它会引发黑胫病，在全球范围内导致显著的产量损失。使用携带主要抗性基因的品种是最有效的防治方法之一。然而，主要基因的功效与病原菌群体中相应无毒基因的频率有关。在本文中，我们报告了德国北部和中部地区病原菌群体的基因图谱及其交配型比例。通过在一套鉴别品种上进行子叶试验或扩增无毒基因特异性PCR标记，对574个分离株中的11个基因进行了鉴定。确定了52个生理小种，其中最主要的生理小种是。结果表明，抗性基因完全无效，其他一些主要基因如、和部分有效（相应无毒基因频率≤42%），而、、、和在我们所调查的德国田间仍能提供相对有效的抗性（相应无毒基因频率为63 - 100%）。有性生殖是增强病原菌在选择压力下进化潜力的一个因素。在所检测的地区，病原菌群体的交配型比例未偏离1:1，这表明有性生殖和子囊孢子在病原菌的生活史中起着核心作用。总体而言，本研究为通过实施油菜品种轮作来制定德国主要抗病基因有效性的战略保护计划提供了重要数据集。
