SHORT COMMUNICATION Fruit spot of sweet lime (Citrus limetta) caused by Septoria sp. in Peru Luis A. A ´ lvarez-Bernaola Æ Javier Javier-Alva Æ Antonio Vicent Æ Maela Leo ´n Æ Jose ´ Garcı ´a-Jime ´nez Received: 27 October 2006 / Accepted: 19 April 2007 / Published online: 15 May 2007 Ó KNPV 2007 Abstract In 2002, a severe fruit spot of sweet lime (Citrus limetta) was observed in Piura and Lambaye- que provinces in northern Peru. Affected fruits showed large oval and sunken lesions, often surrounded by chlorotic haloes. Septoria sp. was isolated from affected fruits. Sweet lime isolates showed larger pycnidia and pycnidiospores than those of Septoria spp. previously described on citrus. In addition, phylogenetic analysis of the ITS sequences clearly separated the sweet lime isolates from S. citri and S. citricola. Isolates were pathogenic to detached sweet lime fruits and the fungus was isolated from lesions on inoculated fruits. Keywords Coelomycete Á Plant pathogen A total of 1,100 ha of sweet lime (Citrus limetta) are cultivated in the Inter-Andean valleys in northern Peru. This area is characterized by a temperate sub- humid climate. Average temperature during the summer is 248C and 128C during the winter months. Average annual rainfall is 350 mm, but severe rainy episodes in summer are frequent due to the influence of the marine current of El Nin ˜o. Sweet lime fruits are mainly produced for the fresh market and for the essential oil industry. In 2002, a fruit spot symptom was observed in several sweet lime orchards in Piura and Lambayeque provinces. Fruits showed shallow lesions with a small central grey to tan crater usually with a dark brown rim, 4–10 mm diam (Fig. 1a). Often, pycnidia were observed inside the spots. Symptoms were restricted to the rind and did not cause internal decay, but made the fruit unsuitable for the fresh market or for the oil industry. Symptoms on leaves were not observed in any of the orchards surveyed. Although the disease was initially of negligible importance, the disease is currently extremely severe in some areas, resulting in >50% unmarketable fruits due to lesions. The objective of this study was to clarify the etiology of the disease. Pycnidium-containing tissues were excised from fruit lesions and were placed on potato dextrose agar (PDA) medium (Biokar diagnostics—France) sup- plemented with 50 mg ml À1 streptomycin sulphate. Dishes were incubated in the dark at 248C and examined daily for 7 days. The colonies that devel- oped were transferred to PDA, and potato carrot agar (PCA), and were incubated under 12-h night: day L. A. A ´ lvarez-Bernaola (&) Á A. Vicent Á M. Leo ´n Á J. Garcı ´a-Jime ´nez Instituto Agroforestal Mediterra ´neo, Universidad Polite ´cnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain e-mail: luialber@eaf.upv.es J. Javier-Alva Departamento de Sanidad Vegetal, Universidad Nacional de Piura, Campus Universitario s/n. Urb. Miraflores, Piura, Peru 123 Eur J Plant Pathol (2007) 118:295–298 DOI 10.1007/s10658-007-9147-3