College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning 110866, China.
National Pesticide Engineering Research Center, Nankai University, Tianjin 300071, China.
Plant Dis. 2020 Aug;104(8):2082-2085. doi: 10.1094/PDIS-01-20-0009-RE. Epub 2020 Jun 18.
Wheat stem rust caused by f. sp. is an important wheat disease with sudden and devastating characteristics. The appearance and spread of new f. sp. races (Ug99, TKTTF, and TTTTF) have once again renewed the interest in the prevention and control of wheat stem rust. Fungicides can effectively control the epidemics of this disease in a short period of time. However, the fungal pathogen is prone to developing resistance. Therefore, we collected 89 isolates of f. sp. from four provinces in China and used the spore germination method to test the sensitivity of the isolates to fungicide triadimefon. Seven relatively triadimefon-sensitive isolates and six relatively triadimefon-resistant isolates were further tested for sensitivity to fungicides carbendazim, mancozeb, thiophanate-methyl, and kresoxim-methyl. The results showed that the mean concentration for 50% of maximal effect of the isolates to triadimefon was 16.14 mg·liter, and the mean resistance factor was 4.48. Only 29 isolates were resistant to triadimefon in which 27 isolates had low levels of resistance and 2 isolates had moderate levels of resistance. However, most of the 89 isolates had no resistance to triadimefon. There was a positive correlation between resistance to triadimefon and carbendazim, but there was no cross-resistance between triadimefon resistance with thiophanate-methyl or kresoxim-methyl resistance. This study provides valuable information for managing fungicide resistant isolates of f. sp. .
由小麦秆锈病菌引起的小麦秆锈病是一种具有突发性和毁灭性特征的重要小麦病害。新的小麦秆锈病菌生理小种（Ug99、TKTTF 和 TTTTF）的出现和传播再次引起了人们对小麦秆锈病防治的关注。杀菌剂可以在短时间内有效控制该病的流行。然而，真菌病原体容易产生抗药性。因此，我们从中国四个省收集了 89 个小麦秆锈病菌株，采用孢子萌发法测定了这些菌株对三唑酮的敏感性。进一步对 7 个相对三唑酮敏感的菌株和 6 个相对三唑酮抗性的菌株进行了杀菌剂多菌灵、代森锰锌、噻菌灵和肟菌酯敏感性测试。结果表明，这些菌株对三唑酮的 50%最大效应浓度的平均值为 16.14 毫克/升，抗性因子的平均值为 4.48。只有 29 个菌株对三唑酮表现出抗性，其中 27 个菌株表现出低水平抗性，2 个菌株表现出中水平抗性。然而，89 个菌株中的大多数对三唑酮没有抗性。三唑酮与多菌灵之间存在正相关性，但三唑酮抗性与噻菌灵或肟菌酯抗性之间没有交叉抗性。这项研究为管理小麦秆锈病菌的抗药性菌株提供了有价值的信息。
