Rodríguez C M, Obando J J, Villalobos W, Moreira L, Rivera C
Instituto del Café de Costa Rica.
Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica.
Plant Dis. 2001 Sep;85(9):1027. doi: 10.1094/PDIS.2001.85.9.1027A.
In 1995, severe symptoms were observed on 'Caturra' and 'Catuaí' coffee (Coffea arabica L.) varieties in farms in the southern part of the Central Valley in Costa Rica. Symptoms were reduced leaf size, malformation of leaves, curling of leaf edges, shortening of internodes, and severe leaf chlorotic mosaic, which sometimes became necrotic. Abortion of flowers and young beans was also observed, with a reduction in yield. Plants also showed irregular growth with an atypical curling appearance that gave rise to the Spanish name "crespera." Ten and three healthy plants were inoculated by grafting in the greenhouse, using infected and healthy budwoods, respectively. Approximately 6 months after inoculation, 3 of 10 grafted plants with infected budwoods showed symptoms of leaf chlorosis, curling, and malformation of leaves and bunched new flushes. Samples of 39 symptomatic plants collected from the field and samples of 3 healthy plants maintained in the greenhouse were tested by enzyme-linked immunosorbent assay (ELISA). All (100%) analyzed symptomatic samples were positive for X. fastidiosa, and all healthy controls were negative. The symptoms observed in Costa Rica are different from those described for coffee leaf scorch in Brazil (1,2), but the climatological conditions and soil type present in Costa Rica are also very different from the areas where X. fastidiosa occurs in Brazil. Leafhoppers were collected randomly in one of the most affected regions. Graphocephala permagna and Erythrogonia sonora were the most frequent insect species found associated with coffee. In ELISA, 34.5% (10 of 29) and 23.8% (5 of 21) of the collected specimens belonging to G. permagna and E. sonora, respectively, tested positive for X. fastidiosa. These positive ELISAs do not necessarily mean that the insect is a vector. The results presented here extend the known geographic distribution of X. fastidiosa. To our knowledge, this is the first report of X. fastidiosa in coffee in Costa Rica. References: (1) M. J. G. Beretta et al. Plant Dis. 80:821, 1996. (2) de Lima et al. Plant Dis. 82:94, 1998.
1995年，在哥斯达黎加中央山谷南部农场的“卡图拉”和“卡图艾”咖啡（阿拉伯咖啡）品种上观察到严重症状。症状包括叶片尺寸减小、叶片畸形、叶缘卷曲、节间缩短以及严重的叶片褪绿花叶病，有时会发展为坏死。还观察到花朵和嫩豆败育，产量下降。植株还表现出不规则生长，呈现出非典型的卷曲外观，由此产生了西班牙语名称“crespera”。在温室中分别用感染和健康的接穗对10株和3株健康植株进行嫁接接种。接种后约6个月，10株嫁接了感染接穗的植株中有3株出现叶片黄化、卷曲、叶片畸形和新梢丛生的症状。对从田间采集的39株有症状植株的样本以及温室中保存的3株健康植株的样本进行了酶联免疫吸附测定（ELISA）。所有（100%）分析的有症状样本对桑氏木质部菌呈阳性，所有健康对照均为阴性。在哥斯达黎加观察到的症状与巴西描述的咖啡叶焦枯症状不同，但哥斯达黎加的气候条件和土壤类型也与巴西桑氏木质部菌发生地区有很大差异。在受灾最严重的地区之一随机采集叶蝉。大斑叶蝉和索诺拉红腹叶蝉是与咖啡相关的最常见昆虫种类。在ELISA检测中，分别属于大斑叶蝉和索诺拉红腹叶蝉的采集标本中，有34.5%（29份中的10份）和23.8%（21份中的5份）对桑氏木质部菌检测呈阳性。这些ELISA阳性结果不一定意味着该昆虫是传播媒介。此处呈现的结果扩展了桑氏木质部菌已知的地理分布范围。据我们所知，这是桑氏木质部菌在哥斯达黎加咖啡上的首次报道。参考文献：(1) M. J. G. Beretta等人，《植物病害》80:821，1996年。(2) 德利马等人，《植物病害》82:94，1998年。
