Advanced lentil lines screened for resistance to Fusarium oxysporum f. sp. lentis under greenhouse and field conditions N. Mohammadi & H. Puralibaba & E. Mohammadi Goltapeh & A. Babaie Ahari & B. Pakdaman Sardrood Received: 24 May 2011 /Accepted: 25 September 2011 /Published online: 23 November 2011 # Springer Science+Business Media B.V. 2011 Abstract Fusarium oxysporum f. sp. lentis is the most important pathogen of lentil plants, and most areas under lentil cultivation are reported to have a fusarium wilt disease background. The plants are infected in the seedling stage and later stages of their development. Fusarium wilt disease, which has appeared at high incidence rates during recent years, has caused sharp drops in the yield, especially in Moghan, in the northwest of Iran. Forty-five isolates of the pathogen were collected from different regions of the country with two isolates from ICARDA in the summer of 2008 and identified using Nelson’ s key. The pathogenicity of the collected isolates was studied on a sensitive line (ILL 4605) under greenhouse conditions and significant differences in pathogenicity were found among them. The most pathogenic isolates from three provinces, East Azerbaijan (EA 30), Ardebil (Ar 3) and Khorasan (Kh 45), were selected and used in screening of 55 developed lines under greenhouse and field conditions. In the greenhouse, test plants were inoculated by immersing root tips in spore suspension and sowing seeds in pre-infested pot soil. Field tests were carried out in a naturally highly infested farm. At all stages, the plant response to the disease was based on the percentage of dead plants. Cluster analyses of the greenhouse and field data led to the selection of three lines (81S15, FLIP2007-42 L and FLIP2009-18 L) that were resistant under greenhouse and field conditions. Keywords ICARDA . Iran . Lens culinaris . Resistant lines Lentil (Lens culinaris Medikus) is regarded as the oldest pulse crop, probably domesticated in habitation up to 13,000 years BC. It is grown today mainly in India, Bangladesh, Pakistan, Egypt, Greece, Italy, countries in the Mediterranean region and North America. It is also cultivated along the Atlantic coast of Spain and Morocco. The crop is of high significance in cereal-based systems because of its nitrogen-fixing ability, its highly protein-rich seeds used in human nutrition and its straw for animal feeding. It is widely used in a range of dishes and reputed to have many uses in traditional medicine (Yadav et al. 2007). Fusarium oxysporum Schlecht. emend. Snyder & Hansen, as one of the most important fungal species Phytoparasitica (2012) 40:69–76 DOI 10.1007/s12600-011-0201-5 N. Mohammadi : E. M. Goltapeh (*) : B. P. Sardrood Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran e-mail: emgoltapeh@modares.ac.ir E. M. Goltapeh e-mail: emgoltapeh@yahoo.com H. Puralibaba Dryland Agriculture Research Institute, Maragheh, Iran A. B. Ahari Plant Protection Department, Faculty of Agriculture, Tabriz University, Tabriz, Iran