DNA markers linked to eastern filbert blight resistance in “Ratoli” hazelnut (Corylus avellana L.)

Abstract

Eastern filbert blight (EFB), caused by the pyrenomycete Anisogramma anomala (Peck) E. Müller, is a major disease problem and production constraint in orchards of European hazelnut (Corylus avellana L.) in Oregon's Willamette Valley. Host genetic resistance is viewed as the most economical means of controlling this disease. A dominant resistance gene from "Gasaway" has been used extensively in the hazelnut breeding program at Oregon State University, but concern about the durability of a single resistance gene stimulated a search for new sources of resistance. "Ratoli," a minor cultivar from Spain, showed no signs or symptoms of the fungus following a series of inoculations. The objective of this study was to study segregation for disease response in two progenies from crosses of Ratoli with susceptible selections and identify linked DNA markers. About half of the seedlings were resistant, suggesting control by a dominant allele at a single locus. A total of 900 random amplified polymorphic DNA (RAPD) primers and 64 amplified fragment length polymorphism (AFLP) primer combinations were screened. Four RAPD markers and two ALFP markers were identified and a linkage map constructed. On this map, disease resistance was flanked by AFLP marker C4-255 and RAPD marker G17-800 at distances of 0.4 cM and 2.8 cM, respectively. Based on co-segregation with SSR markers, Ratoli resistance was assigned to linkage group 7 while Gasaway resistance is on linkage group 6. Ratoli provides a novel source of EFB resistance, and robust RAPD marker G17-800 is useful for marker-assisted selection.

A Draft Genome and High-Density Genetic Map of European Hazelnut (Corylus avellanaL.)

“…Disease resistance is often involves several loci and pathways; the resistance and susceptibility to EFB displayed in certain accessions ( Table 4) is highly unlikely to involve the same genes. For example, the EFB resistance locus in the Spanish accession 'Ratoli' maps to a different linkage group than that of the cultivar 'Gasaway' and may offer a more robust source of resistance (22,51). Variation in nucleotide sequences among hazelnut populations in different geographic regions, have the potential to introduce polymorphisms in coding loci.…”

“…This resolution allows genome-wide analyses of molecular variation and additional marker discovery to accelerate molecular breeding in hazelnut. For example, the EFB-resistance in 'Gasaway' was previously assigned to LG6 (22), and the separate gene responsible for resistance in the Spanish cultivar 'Ratoli' segregates on LG7 (51). In addition, the recently characterized accession OSU 759.010 transmits resistance via a locus on LG2 (53) different from locations of other identified resistance loci.…”

Sources of resistance to eastern filbert blight in hazelnuts from the Republic of Georgia

“…Various C. avellana cultivars, seedlings, and interspecific hybrids have since displayed resistance to EFB in Oregon and are now being used in breeding. The most notable EFB-resistant C. avellana include 'Ratoli' and 'Culpla' from Spain, 'Crevenje' and 'Uebov' from Serbia, OSU 495.027 from southern Russia, OSU 408.040 from Minnesota, USA, CCOR 187 from Finland, and OSU 759.010 from Georgia, which is discussed in more detail later in this article (Chen et al, 2005(Chen et al, , 2007Colburn et al, 2015;Coyne et al, 1998;Lunde et al, 2000;Sathuvalli et al, 2009Sathuvalli et al, , 2010Sathuvalli et al, , 2011a. Additional EFB-resistant seedling selections from Turkey, Russia, and Crimea have also more recently been identified at OSU that merit further testing (Mehlenbacher, personal communication, November 19, 2014).…”

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

“…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).…”

“…Many types of markers have been investigated in hazelnut, including random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and microsatellite, the latter also known as simple sequence repeat (SSR) markers (Chen et al, 2005;Davis and Mehlenbacher, 1997;Mehlenbacher et al, 2004;Sathuvalli et al, 2011aSathuvalli et al, , 2011bSathuvalli et al, , 2012. The RAPD markers 152 800 and 268 580 are routinely used in marker-assisted selection (MAS) for EFB resistance from 'Gasaway' (Davis and Mehlenbacher, 1997;Mehlenbacher et al, 2004).…”