Giffoni’, ‘Tonda Romana’ ( Manzo and Tamponi, 1982 ), and ‘Tonda Italiana’ from Italy (this last one, an IRTA selection from Italian material); and ‘Clark’, ‘Lewis’, and ‘Willamette’ from the hazelnut breeding program at OSU ( Mehlenbacher et al., 1991
‘Gasaway’, controlled by a dominant allele at a single locus ( Mehlenbacher et al., 1991 ), has been extensively used in the hazelnut breeding program at OSU. Most advanced selections and recently released cultivars and pollenizers carry ‘Gasaway
, breeders and growers in the eastern United States have made crosses between European and wild American hazelnuts in an attempt to combine the superior nut traits of the European species with the EFB tolerance of the wild American species. Breeding efforts
expense to hazelnut production as a result of the need for copious fungicide sprays, scouting for cankers, and pruning of infected wood. Breeding for resistance to EFB is considered to be the most cost-effective means of control ( Johnson et al., 1996
zones that nearly span the latitudinal range of the United States. Thus, if systematically exploited for breeding interspecific hybrids, C. americana may enable the expansion of commercial hybrid hazelnut production to a wide portion of the eastern and
’, conferred by a dominant allele at a single locus ( Mehlenbacher et al., 1991 ), has been extensively used in the hazelnut breeding program at Oregon State University (OSU). Most resistant selections from the breeding program carry ‘Gasaway’ resistance. In
annotated in the version 1 (V1) genome sequence of ‘Jefferson’ produced by sequencing using Illumina (San Diego, CA) technology (Rowley et al., 2018). The hazelnut breeding programs at OSU and Rutgers University have identified more than 150 accessions
Eastern filbert blight is a serious threat to hazelnut (Corylus avellana) production in the Pacific NW. Susceptible genotypes inoculated with the causal fungus, Anisogramma anomala, require 16 to 28 months of incubation to develop symptoms. A rapid and accurate screening system was needed to identify resistant genotypes in the OSU hazelnut breeding program, particularly in progenies segregating 1:1 for a single dominant resistance gene from the variety `Gasaway'. An indirect enzyme-linked immunosorbant assay (ELISA) system was developed using polyclonal antibodies obtained by injecting New Zealand rabbits with antigens from pure cultures of A. anomala. The antiserum produced a positive reaction to the fungus in 1000-fold dilutions of the extracts from infected hazelnut tissue but did not react to 10-fold dilutions of healthy tissue in indirect ELISA.
107 POSTER SESSION (Abstr. 305–315) Breeding and Genetics–Fruits/Nuts
Hazelnuts in Oregon are grown on 30,000 acres by ≈1000 orchardists in the Willamette Valley. Their annual production accounts for 3% to 5% of the world's hazelnut tonnage. The trees are grown in a single trunk system wrtb an average spacing of 20 feet between trees. Mechanical harvestihg is done in October. The industry employs an Integrated Pest Management approach, utilizing combinations of scouting, trapping, and biological control. The main insect pests are filbertworm, filbert leafroller, obliquebanded leafroller, and filbert aphids. The aphid parasite Trioxys pallidus was imported from Europe and successfully established in Oregon. Eastern Filbert Blight, Anisogramma anomala, a fungus disease, is the most serious disease problem in the industry. Annual applications of nitrogen to the soil and boron applied to the foliage are routine for Oregon's hazelnut growers. OSU research has quantified the importance of good light distribution in the tree canopy for increased nut production. OSU recommends a 5-year rotational pruning program. Some growers use mechanical hedging instead of hand pruning. OSU is home to the world's largest hazelnut breeding program. `Barcelona' is still the main, cultivar grown, while `Ennis' is the main in-shell variety. There is growing interest in planting varieties with a high percent kernel, such as `Casina', `Willamette', and `Lewis'.