Wheat stripe rust epidemics and races of Puccinia striiformis f. sp tritici in the United States in 2000
Wheat stripe rust epidemics and races of Puccinia striiformis f. sp tritici in the United States in 2000
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DOI：
10.1094/pdis.2002.86.1.39
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发表时间：
2002-01-01
期刊：
影响因子：
4.5
通讯作者：
Jackson, L
中科院分区：
文献类型：
--
作者：
Chen, XM;Moore, M;Jackson, L
小麦条锈菌Puccinia striiformis f.sp.小麦是美国西部最具破坏性的疾病，在中南部各州变得越来越重要。合作者通过实地调查和美国各地的疾病托儿所对这种疾病进行了监测。2000年，条锈病在全国20多个州发生，是有记载以来最普遍的一次。尽管许多州的杀菌剂应用减少了产量损失，但这种疾病在美国造成了数百万美元的损失，特别是在阿肯色州和加利福尼亚州。其中一个流行品种RSI 5在加利福尼亚州萨克拉门托-圣华金三角洲地区的产量损失约50%。在太平洋西北部，小麦因条锈病造成的损失很小，因为具有持久抗性的品种被广泛种植，而2000年5月的天气不利于该病的发生。为了鉴定该病原菌的小种，对来自美国20个州的20个不同小麦品种的条锈病样品进行了分析，其中包括Clement(Yr9，YrCle)、CompAir(Yr8，Yr19)以及Yr8和Yr9近等基因系。2000年，确定了21个以前已确定的小种和21个新的小种。在21个新小种中，8个是毒力组合已知存在于美国的病毒型，13个对Yr8、Yr9、Clement或CompAir中的一个或多个品系具有毒力。这是美国首次报道Yr8和Yr9的毒力。大多数新的种族在Express上也是致命的。自1998年以来，加利福尼亚州已经发现了在Express上具有致命性的种族。2000年，Yr8、Yr9和Express上的致病小种在加利福尼亚州和落基山脉以东的各州广泛分布。2000年的疫情表明，在加利福尼亚州、中南部各州和大平原的其他一些州，需要加大抗条锈病育种的力度。抗药性基因的多样化和持久抗药性的使用应该可以防止大规模和严重的流行病。
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is most destructive in the western United States and has become increasingly important in the south-central states. The disease has been monitored by collaborators through field surveys and in disease nurseries throughout the United States. In the year 2000, stripe rust occurred in more than 20 states throughout the country, which was the most widespread occurrence in recorded history. Although fungicide applications in many states reduced yield losses, the disease caused multimillion dollar losses in the United States, especially in Arkansas and California. One of the prevalent cultivars, RSI 5, had a yield loss of about 50% in the Sacramento-San Joaquin Delta region of California. In the Pacific Northwest, wheat losses due to stripe rust were minimal because cultivars with durable resistance were widely grown and the weather in May 2000 was not favorable for the disease. To identify races of the pathogen, stripe rust collections from 20 states across the United States were analyzed on 20 wheat differential cultivars, including Clement (Yr9, YrCle), Compair (Yr8, Yr19), and the Yr8 and Yr9 near-isogenic lines. In 2000, 21 previously identified races and 21 new races were identified. Of the 21 new races, 8 were pathotypes with combinations of virulences previously known to exist in the United States, and 13 had virulences to one or more of the lines Yr8, Yr9, Clement, or Compair. This is the first report of virulence to Yr8 and Yr9 in the United States. Most of the new races were also virulent on Express. Races that are virulent on Express have been identified in California since 1998. The races virulent on Yr8, Yr9, and Express were widely distributed in California and states east of the Rocky Mountains in 2000. The epidemic in 2000 demonstrates that increased efforts to breed for stripe rust resistance are needed in California, the south-central states, and some other states in the Great Plains. Diversification of resistance genes and use of durable resistance should prevent large-scale and severe epidemics.