Lucero X, Wright E R, Pérez B A
Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453 (C1417DSE), Buenos Aires, Argentina.
INTA-IMYZA, C.C. 25 (B1712WAA), Castelar, Buenos Aires, Argentina.
Plant Dis. 2008 Apr;92(4):653. doi: 10.1094/PDIS-92-4-0653B.
In the fall of 2003, severity of late leaf rust in leaves and fruits of red raspberry (Rubus idaeus L.) reached 50% in Buenos Aires (Azul, Baradero, Capilla del Señor, Gral. Rodríguez, Mar del Plata, and Tandil), Córdoba (Villa de Las Rosas), and Entre Ríos (Concordia). The south of Argentina, Río Negro (El Bolsón), and Chubut (El Hoyo, Lago Puelo) remained rust free. The abaxial side of the field infected leaves had pustules filled with masses of yellow spores. Chlorotic areas corresponded in the adaxial side. Urediospores were vacuum harvested from field infected leaves collected in the Tandil area and placed onto a healthy 1-year-old greenhouse-grown plant (cv. Heritage). Spores from a single pustule were increased on plants of the same cultivar. Spores were studied with optic and electronic microscopy. Uredial ostiolar cells were warted, laterally free, and constricted in the middle. The obovoid, echinulate urediospores, from infected leaves averaged 24 × 16 μm (16 to 30 × 11 to 21 μm). Morphological characteristics and spore measurements agreed with those reported for Pucciniastrum americanum (1). Urediniospores were suspended in mineral oil and sprayed onto three raspberry cultivars that were maintained in a darkened mist chamber at 20°C for 48 h and the transferred to a 20°C and 12-h light cycle chamber. Control plants were inoculated with sterile water. There were three replicate plants of each treatment. After 11 days, large sporulating uredia (0.5 mm) were produced on inoculated leaves of cv. Autumn Bliss and smaller uredia (0.1 to 0.3 mm) were produced on cv. Heritage. There were necrotic flecks and the least and smallest uredia were produced on cv. Himbo Queen. No symptoms were present in control plants. To our knowledge, this is the first report of P. americanum causing disease on raspberry in Argentina. Reference: (1) G. F. Laundon and A. F. Rainbow. Pucciniastrum americanum. No. 210 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, England, 1969.
2003年秋季，布宜诺斯艾利斯省（阿苏尔、巴拉德罗、卡皮利亚德尔塞尼奥尔、罗德里格斯将军镇、马德普拉塔和坦迪尔）、科尔多瓦省（拉斯罗萨斯镇）和恩特雷里奥斯省（康科迪亚）的红树莓（悬钩子属）叶片和果实上的晚叶锈病严重程度达到了50%。阿根廷南部的内乌肯省（埃尔博尔松）和丘布特省（埃尔霍约、普埃洛湖）未出现锈病。田间感染叶片的背面有充满黄色孢子团的脓疱。正面有相应的褪绿区域。从坦迪尔地区田间感染的叶片上真空采集夏孢子，并接种到一株健康的1年生温室培育植株（品种为“传承”）上。从单个脓疱中获取的孢子在同一品种的植株上进行增殖培养。利用光学显微镜和电子显微镜对孢子进行研究。夏孢子堆孔细胞有疣状突起，侧面游离，中部缢缩。从感染叶片上获得的倒卵形、具刺夏孢子平均大小为24×16微米（16至30×11至21微米）。形态特征和孢子测量结果与美洲柱锈菌的报道相符（1）。将夏孢子悬浮于矿物油中，喷洒到三个树莓品种上，这些植株在20℃的黑暗雾室中放置48小时，然后转移到20℃、12小时光照周期的培养室中。对照植株接种无菌水。每个处理设置三株重复植株。11天后，在“秋福”品种的接种叶片上产生了大型产孢夏孢子堆（0.5毫米），在“传承”品种上产生了较小的夏孢子堆（0.1至0.3毫米）。在“辛波皇后”品种上有坏死斑点，产生的夏孢子堆最少且最小。对照植株未出现症状。据我们所知，这是美洲柱锈菌在阿根廷导致树莓发病的首次报道。参考文献：（1）G. F. 劳登和A. F. 雷恩博。美洲柱锈菌。载于《病原真菌和细菌描述》第210号。英联邦真菌研究所，英国萨里郡邱园，1969年。
