Flores R C, Loyo J R, Ojeda R A, Rangel O C A, Cerón F A, Márquez W, Guerra-Moreno A S, Hernandez-Ibarra H M, González R E, Castlebury L A, Dixon L J, Glynn N C, Comstock J C, Flynn J, Amador J
Cámara Nacional de las Industrias Azucarera y Alcoholera, Río Niágara No. 11, Mexico, D.F.
Central Izalco, Grupo CASSA, Sonsonate, El Salvador.
Plant Dis. 2009 Dec;93(12):1347. doi: 10.1094/PDIS-93-12-1347B.
Symptoms of sugarcane orange rust were observed on July 17, 2008 on sugarcane cvs. Mex 57-1285, Mex 61-230, and Co 301 (a clone received in Mexico in 1953) at the Centro de Investigación y Desarrollo de la Caña de Azúcar en Tuxtla Chico, Chiapas, Mexico. In El Salvador, from August 2008 through January 2009, rust symptoms were observed on cv. CP 72-2086 (previously resistant to brown rust caused by Puccinia melanocephala Syd. & P. Syd.) in 117 dispersed sugarcane-production fields in various localities of El Salvador. Likewise, rust symptoms were first observed on sugarcane cv. SP 74-8355 (more than 25% severity and considered resistant to brown rust) at Natá, Coclé Province in Panama from January to February 2008. Dried herbarium leaf samples of sugarcane rust-infected leaves collected in El Salvador and Mexico were sent to the ARS, USDA Systematic Mycology and Microbiology Laboratory in Beltsville MD for identification. Panamanian samples were collected similarly and analyzed at the CALESA Biotechnology Laboratory. Morphological features of uredinial lesions and urediniospores were distinct from those of P. melanocephala and consistent with P. kuehnii E. J. Butler observed previously on specimens from Florida, Guatemala, Costa Rica, and Nicaragua (1-3). Analysis of the ITS1, 5.8S, and ITS2 and 28S large subunit rDNA sequences of the rust on infected cvs. Mex 57-1285, Mex 61-230, and Co 301 (BPI 878930, 879139, and 879140; GenBank Accession Nos. GO283006, GO283004, and GO283005, respectively) from Mexico and cv. CP 72-2086 from three locations in El Salvador (BPI 879135, 879136, and 879137; GenBank Accession Nos. GO283009, GO283007, and GO283008, respectively) all confirmed the identification of P. kuehnii. Similar analysis of the ITS1, 5.8S, and ITS2 rDNA sequence for the rust infecting cv. SP 74-8355 (GenBank Accession No. GO281584) confirmed the identification of P. kuehnii in Panama. To our knowledge, this is the first report of P. kuehnii causing orange rust disease of sugarcane in El Salvador, Mexico, and Panama. These findings also confirm the wider distribution of orange rust in the Western Hemisphere. References: (1) E. Chavarria et al. Plant Dis. 93:425, 2009. (2) J. C. Comstock et al. Plant Dis. 92:175, 2008. (3) W. Ovalle et al. Plant Dis. 92:973, 2008.
2008年7月17日，在墨西哥恰帕斯州图斯特拉奇科的甘蔗研究与发展中心，在甘蔗品种Mex 57 - 1285、Mex 61 - 230和Co 301（1953年引入墨西哥的一个克隆品种）上观察到甘蔗橙锈病症状。在萨尔瓦多，从2008年8月到2009年1月，在萨尔瓦多各地117个分散的甘蔗生产田中，在品种CP 72 - 2086（以前对由黑孢柄锈菌引起的褐锈病具有抗性）上观察到锈病症状。同样，2008年1月至2月在巴拿马科克莱省纳塔，首次在甘蔗品种SP 74 - 8355（严重程度超过25%且被认为对褐锈病具有抗性）上观察到锈病症状。在萨尔瓦多和墨西哥采集的感染甘蔗锈病的干燥标本室叶片样本被送往位于马里兰州贝尔茨维尔的美国农业部农业研究局系统真菌学和微生物学实验室进行鉴定。巴拿马的样本也以类似方式采集并在CALESA生物技术实验室进行分析。夏孢子堆病斑和夏孢子的形态特征与黑孢柄锈菌不同，与之前在来自佛罗里达、危地马拉、哥斯达黎加和尼加拉瓜的标本上观察到的古巴柄锈菌一致(1 - 3)。对感染品种Mex 57 - 1285、Mex 61 - 230和Co 301（分别为BPI 878930、879139和879140；GenBank登录号分别为GO283006、GO283004和GO283005）的锈菌的ITS1、5.8S、ITS2和28S大亚基rDNA序列分析，以及来自萨尔瓦多三个地点的品种CP 72 - 2086（BPI 879135、879136和879137；GenBank登录号分别为GO283009、GO283007和GO283008）均证实为古巴柄锈菌。对感染品种SP 74 - 8355的锈菌的ITS1、5.8S和ITS2 rDNA序列（GenBank登录号GO281584）进行的类似分析也证实巴拿马的锈菌为古巴柄锈菌。据我们所知，这是古巴柄锈菌在萨尔瓦多、墨西哥和巴拿马引起甘蔗橙锈病的首次报道。这些发现也证实了橙锈病在西半球分布更广。参考文献：(1) E. Chavarria等人，《植物病害》93:425，2009年。(2) J. C. Comstock等人，《植物病害》92:175，2008年。(3) W. Ovalle等人，《植物病害》92:973，2008年。
