European hazelnut (Corylus avellana L.) is an important world crop. In the United States, hazelnuts are produced primarily in the Willamette Valley of Oregon and represent 4% to 5% of the world total (FAOStat, 2009). However, the Oregon hazelnut industry is threatened by the disease eastern filbert blight (EFB) caused by the pyrenomycete Anisogramma anomala (Peck) E. Müller. The fungus, an obligate biotroph with a 2-year life cycle (Pinkerton et al., 1995), causes severe stem cankers on commercially important European hazelnuts. Ascospores are released from perithecia during periods of branch wetness in winter and spring and dispersed by splashing rain and air currents. The spores germinate and produce hyphae that directly penetrate young growing shoots in the spring. The hyphae permeate and destroy the cambial layer, and cankers bearing stromata become visible 16 to 18 months after initial infection (Johnson et al., 1994; Pinkerton et al., 1998; Stone et al., 1992). Control measures include scouting and pruning infected branches below the cankers plus fungicide treatments at 2-week intervals starting at budbreak (Pscheidt, 2006).
Host genetic resistance is a desirable way to avoid the expense and time involved in scouting, pruning, and spraying to control this disease (Mehlenbacher, 1995). The resistance from ‘Gasaway’, an obsolete pollinizer (Mehlenbacher et al., 1991), has been extensively used in the hazelnut breeding program at Oregon State University (OSU). Concern over the durability of this single resistance gene prompted this search for new sources of resistance to EFB. Inoculations by Molnar (2006) with different isolates of A. anomala showed that an isolate from Michigan produced a few cankers on ‘Gasaway’ and suggested genetic diversity among isolates of the pathogen. A series of studies (Chen et al., 2007; Coyne et al., 1998; Lunde et al., 2000) has identified several new sources of resistance. Molecular markers linked to resistance have been identified for some of these (Chen et al., 2005; Sathuvalli, 2007). In this study, the response of 86 hazelnut accessions recently introduced from several countries was evaluated after greenhouse inoculations with the EFB pathogen.
Chen, H., Mehlenbacher, S.A. & Smith, D.C. 2005 AFLP markers linked to eastern filbert blight resistance from OSU 408.040 hazelnut J. Amer. Soc. Hort. Sci. 130 412 417
Chen, H., Mehlenbacher, S.A. & Smith, D.C. 2007 Hazelnut accessions provide new sources of resistance to eastern filbert blight HortScience 42 466 469
Coyne, C.J., Mehlenbacher, S.A. & Smith, D.C. 1998 Sources of resistance to eastern filbert blight in hazelnut J. Amer. Soc. Hort. Sci. 123 253 257
FAOStat 2009 24 Dec. 2009 <http://faostat.fao.org/site/567/default.aspx#ancor>.
Johnson, K.B., Pinkerton, J.N., Gaudreault, S.M. & Stone, J.K. 1994 Infection of European hazelnut by Anisogramma anomala: Site of infection and effect of host development stage Phytopathology 84 1465 1470
Lunde, C.F., Mehlenbacher, S.A. & Smith, D.C. 2000 Survey of hazelnut cultivars for response to eastern filbert blight inoculation HortScience 35 729 731
Mehlenbacher, S.A. 1995 Classical and molecular approaches to breeding fruit and nut crops for disease resistance HortScience 30 466 477
Mehlenbacher, S.A., Thompson, M.M. & Cameron, H.R. 1991 Occurrence and inheritance of immunity to eastern filbert blight in ‘Gasaway’ hazelnut HortScience 26 410 411
Molnar, T.J. 2006 Genetic resistance to eastern filbert blight in hazelnut (Corylus) Ph.D. Diss, Department of Plant Biology, Rutgers, the State University of New Jersey New Brunswick, NJ
Pinkerton, J.N., Johnson, K.B., Stone, J.K. & Ivors, K.L. 1998 Factors affecting the release of ascospores of Anisogramma anomala Phytopathology 88 122 128
Pinkerton, J.N., Stone, J.K., Nelson, S.J. & Johnson, K.B. 1995 Infection of European hazelnut by Anisogramma anomala: Ascospore adhesion, mode of penetration of immature shoots, and host response Phytopathology 88 1260 1268
Pscheidt, J.W. 2006 Potential EFB control programs Proc. of the Nut Growers Society of Oregon, Washington and British Columbia 91 72 78
Sathuvalli, V.R. 2007 DNA markers linked to novel sources of resistance to eastern filbert blight in European hazelnut (Corylus avellana L) M.S. Thesis, Department of Horticulture, Oregon State University Corvallis, OR
Stone, J.K., Johnson, K.B., Pinkerton, J.N. & Pscheidt, J.W. 1992 Natural infection period and susceptibility of vegetative seedlings of European hazelnut to Anisogramma anomala Plant Dis. 76 348 352
The Brooks and Olmo Register of Fruit and Nut Varieties 1997 3rd Ed ASHS Press Alexandria, VA 307