Assessment of Host (Corylus sp.) Resistance to Eastern Filbert Blight in New Jersey

Abstract

<jats:p>One hundred ninety clonal accessions of <jats:italic>Corylus</jats:italic>, including species and various interspecific hybrids of <jats:italic>C. avellana</jats:italic>, <jats:italic>C. americana</jats:italic>, <jats:italic>C. heterophylla</jats:italic>, <jats:italic>C. colurna</jats:italic>, and <jats:italic>C. fargesii</jats:italic>, were assessed for their response to field exposure to the eastern filbert blight (EFB) pathogen, <jats:italic>Anisogramma anomala</jats:italic>, in New Jersey, where the fungus is native. Plants were obtained from the U.S. Department of Agriculture Agricultural Research Service National Clonal Germplasm Repository and Oregon State University, the University of Nebraska, Lincoln, and the National Arbor Day Foundation. Additional plant material was acquired from the Morris and Holden Arboreta and from private nurseries in Amherst, NY, and Niagara-on-the-Lake, Ontario, Canada. The accessions were chosen based on their resistance to EFB in Oregon, a region where <jats:italic>A. anomala</jats:italic> is not native, or anecdotal reports and grower observations of tolerance or resistance to the disease. Trees were planted in the field from 2002 through 2009 in New Jersey where they were exposed to EFB yearly through field inoculations and natural spread. In Jan. 2012, they were visually evaluated for the presence of EFB. The cankers were measured, and the proportion of diseased wood was calculated for susceptible trees. Nearly all accessions reported to be resistant to EFB in Oregon maintained at least a useful level of tolerance in New Jersey with a number remaining free of cankers. However, several accessions developed small to medium-sized cankers and showed branch dieback, including offspring of <jats:italic>C. avellana</jats:italic> ‘Gasaway’. Most <jats:italic>C. americana</jats:italic> and <jats:italic>C. heterophylla</jats:italic> accessions remained free of EFB, although variation in EFB response was found in hybrids of these species with <jats:italic>C. avellana</jats:italic>, ranging from no signs or symptoms to severe EFB. Nearly half of the <jats:italic>C. colurna</jats:italic> × <jats:italic>C. avellana</jats:italic> hybrids developed cankers, whereas each of the <jats:italic>C. fargesii</jats:italic> accessions and most grower selections developed in eastern North America remained free of EFB. The results document the existence of a wide diversity of <jats:italic>Corylus</jats:italic> germplasm that expresses resistance or a high level of tolerance to EFB in New Jersey and confirms previous reports that <jats:italic>C. americana</jats:italic> is highly resistant to the disease. Interestingly, most <jats:italic>C. heterophylla</jats:italic> and the <jats:italic>C. fargesii</jats:italic> were also found to be resistant despite originating in Asia where <jats:italic>A. anomala</jats:italic> has not been found. The various interspecific hybrids show the potential for incorporating EFB resistance from wild species through breeding. The results provide further evidence of differences in disease expression in Oregon and New Jersey, where isolates differ and disease pressure may be higher.</jats:p>

Eastern Filbert Blight Resistance in Hazelnut Accessions ‘Culplà’, ‘Crvenje’, and OSU 495.072

“…New Jersey (Capik and Molnar, 2012;Chen et al, 2007;Molnar et al, 2010;Sathuvalli et al, 2010). The absence of RAPD markers UBC268 580 and UBC152 800 suggests that they do not carry the 'Gasaway' resistance gene, but rather that they are novel.…”

“…It is believed that the seeds were from a cultivar collection in southern Russia (S.A. Mehlenbacher, unpublished). OSU 495.072 has been screened for resistance to EFB in Oregon and New Jersey and has remained free of disease symptoms in both environments (Capik and Molnar, 2012;Molnar et al, 2010;Sathuvalli et al, 2010). OSU 495.072 was crossed with two susceptible parents-OSU 713.068 in 2001 and OSU 651.011 in 2002, generating 112 in progeny 01035 and 14 seedlings in progeny 02020, respectively (Table 1, Fig.…”

“…Many C. americana Marsh. selections are resistant to, or tolerant of, the pathogen (Capik and Molnar, 2012;Muehlbauer et al, 2014), but infections are usually much more severe on european hazelnut (Pinkerton et al, 1993). The life cycle of A. anomala is well documented (Gottwald and Cameron, 1979;Johnson et al, 1996;Pinkerton et al, 1992Pinkerton et al, , 1998aPinkerton et al, , 1998bStone et al, 1992).…”

“…Selections of C. avellana have been found that exhibit qualitative or quantitative resistance to EFB (Capik and Molnar, 2012;Capik et al, 2013;Chen et al, 2005Chen et al, , 2007Lunde et al, 2000Lunde et al, , 2006Mehlenbacher et al, 1991;Muehlbauer et al, 2014;Sathuvalli et al, 2010Sathuvalli et al, , 2011aSathuvalli et al, , 2011bSathuvalli et al, , 2012. 'Gasaway' was the first C. avellana cultivar observed to express a very high level of resistance to EFB (Cameron, 1976).…”

“…However, resistance genes are vulnerable to ''breakdown'' over time as new isolates of the pathogen arise or are introduced (McDonald and Linde, 2002). Accessions expressing very high resistance in Oregon have been screened in New Jersey, where A. anomala is native and disease pressure is high, and EFB cankers with stromata have been observed on some trees, including 'Gasaway' (Molnar et al, 2010;Capik and Molnar, 2012). In Oregon, under high disease pressure, small cankers have been observed on 'Jefferson', 'McDonald', and a few other genotypes that carry the 'Gasaway' resistance gene (S.A. Mehlenbacher, unpublished).…”