plant named ‘Thompson’

Abstract

A new and distinct Corylus avellana plant is disclosed, distinguished by its low vigor, globose growth habit, production of nuts with round kernels that fall free of the husk at maturity, resistance to eastern filbert blight and big bud mite, S-alleles, nut size, kernel percentage, frequency of nut defects, time of pollen shed, and length of the husk or involucre.

Description

ACKNOWLEDGMENT OF GOVERNMENT SUPPORT

This invention was made with government support under Specialty Crops Research Initiative Grant 2016-51181-25412 awarded by the USDA-National Institute of Food and Agriculture and under agreement 58-5358-4-025 awarded by USDA-Agricultural Research Service. The government has certain rights in the invention.

Latin name of the genus and species of the plant claimed: Corylus avellana.

Variety denomination: ‘Thompson’.

INCORPORATION OF ELECTRONIC SEQUENCE LISTING

The Sequence Listing is submitted as an XML file named “Sequence.xml,” created on Oct. 3, 2023, 35,809 bytes, which is incorporated by reference herein.

BACKGROUND

The present invention relates to a new and distinct cultivar of European hazelnut, also known as filbert, and botanically known as Corylus avellana, hereinafter referred to by the name ‘Thompson’. The new Corylus plant resulted from a controlled cross of the female parent Corylus avellana ‘OSU 914.082’ (unpatented) x male parent Corylus avellana ‘OSU 820.007’ (unpatented) made in February 2005 (see, FIG. 1). A tree of ‘OSU 914.082’ was emasculated and covered to prevent foreign pollen contamination. Controlled pollinations used pollen of ‘OSU 820.007’. Hybrid seeds resulting from the cross were harvested in August 2005. They were provided a period of moist chilling, subsequently germinated, and the seedlings were grown in the greenhouse during the summer of 2006. From this cross, a total of 93 seedling trees were planted in a research field in Corvallis, OR, in October 2006. ‘Thompson’ was discovered and selected as a single plant within that progeny of the stated cross-pollination. It was originally assigned the designation ‘OSU 1304.039’, which indicates the row and tree location of the original seedling.

The female parent is ‘OSU 914.082’, obtained from a cross of ‘OSU 315.096’ (unpatented) and ‘Santiam’ (unpatented, Mehlenbacher et al., HortScience 42:715-717, 2007). ‘OSU 315.096’ is from a cross of ‘OSU 23.017’ (unpatented) and ‘Tonda Gentile delle Langhe’ (unpatented) from northern Italy. ‘OSU 23.017’ is from a cross of ‘Barcelona’ (unpatented) and ‘Extra Ghiaghli’ (unpatented). ‘Barcelona’ is an old Corylus avellana cultivar from Spain that is widely distributed in Europe and was introduced to the U.S. in about 1885 (Mehlenbacher and Miller, Fruit Var. J. 43:90-95, 1989). ‘Barcelona’ is known under several different names, including ‘Castanyera’ in Tarragona (Spain), ‘Grande’ in Asturias (Spain), ‘Grada de Viseu’ in Portugal, and ‘Fertile de Coutard’ in France. ‘Extra Ghiaghli’, described by Raptopolous and Kantartzis (1961), is a clone of the important Turkish cultivar ‘Tombul’ and was imported from Greece in the late 1950s. ‘Santiam’ is a parent of ‘McDonald’ (U.S. Plant Pat. No. 28,200).

The male parent is ‘OSU 820.007’, an unreleased selection from a cross of ‘OSU 275.031’ x ‘OSU 504.065’ (both unpatented). ‘OSU 275.031’ is from a cross of ‘Montebello’ (unpatented) from Sicily and ‘OSU 74.037’ (unpatented). The parentage of ‘OSU 74.037’ includes ‘Barcelona’, ‘Daviana’ (unpatented) from England and ‘Tombul Ghiaghli’ (unpatented), a Turkish type from Greece (Raptopolous and Kantartzis, 1961). ‘OSU 504.065’ is a parent of ‘York’ (U.S. Plant Pat. No. 24,972). The pedigree of ‘OSU 504.065’ includes ‘Montebello’, grower selection ‘Compton’ (unpatented), an unknown selection labeled F-4, and ‘Gasaway’ (unpatented, Mehlenbacher et al., HortScience 26:410-411, 1991), the original donor of resistance to eastern filbert blight.

‘Thompson’ was asexually reproduced by rooted suckers in 2012 through 2021 in Corvallis, OR. The unique features of this new Corylus are stable and reproduced true-to-type in successive generations of asexual reproduction.

SUMMARY

The following traits have been observed and are determined to be the unique characteristics of ‘Thompson’. These characteristics in combination distinguish ‘Thompson’ from other know Corylus avellana cultivars, such as ‘Yamhill’ (unpatented, Mehlenbacher et al., HortScience 44:845-847, 2009), ‘Jefferson’ (unpatented, Mehlenbacher et al., HortScience 46:662-664, 2011), ‘McDonald’ (U.S. Plant Pat. No. 28,200), ‘Wepster’ (U.S. Plant Pat. No. 27,141), ‘Barcelona’, and ‘Tonda di Giffoni’ (unpatented), and other cultivars and selections of Corylus avellana known to the inventor:

• • 1. Low vigor and globose plant habit.
  • 2. High level of resistance to eastern filbert blight (EFB) caused by the fungus Anisogramma anomala (Peck) E. Müller. The source of this resistance is a single dominant allele conferred from ‘Gasaway’, which protects Corylus avellana ‘McDonald’, ‘Wepster’, ‘Dorris’ (U.S. Plant Pat. No. 25,022), ‘Jefferson’, ‘Yamhill’, and several other Corylus avellana cultivars and pollinizers.
  • 3. Expression of incompatibility alleles S₂ and S₁₅ in the styles and S₁₅ in the pollen.
  • 4. High resistance to big bud mites (primarily Phytoptus avellanae Nal.).
  • 5. Other distinguishing characteristics include nut size, kernel percentage (ratio of kernel weight to nut weight), frequency of defects (blank nuts, moldy kernels, twin kernels, etc.), time of pollen shed, and length of the husk or involucre.

Female Receptivity: The female inflorescences of ‘Thompson’ emerge early and are fully receptive in mid-January, with ‘McDonald’, but their styles blacken about two weeks earlier than those of ‘McDonald’ (see, FIGS. 5-7).

Pollen Shed: ‘Thompson’ generally sheds pollen in Corvallis, OR in early mid-season, with ‘McDonald’ and before ‘Felix’ (U.S. Plant Pat. No. 24,973) (see, FIGS. 5-7).

Husk Length: The husk of ‘Thompson’ is about 1.3 times nut length, slightly shorter than ‘Barcelona’, while ‘Wepster’ is 2.0 times nut length. The husks have finger-like tips, are slit down the side, and flare open as they dry at maturity (see, FIG. 3). About 92% of the nuts fall free of the husk at maturity.

Nuts and Kernels: ‘Thompson’ produces round, medium-sized nuts and kernels. Most of the pellicle is removed from the kernel with dry heat in the blanching process (see, FIG. 4). The combination of correct size, round shape and good blanching make ‘Thompson’ well-suited to the kernel market for use in confections and baked goods.

The foregoing and other objects and features of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying color photographs illustrate the overall appearance of the new variety, showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. It should be noted that colors may vary, for example due to lighting conditions at the time the photograph is taken. Therefore, color characteristics of this new variety should be determined with reference to the observations described herein, rather than from the photographs alone.

FIG. 1 shows the pedigree of new cultivar ‘Thompson’ (OSU 1304.039).

FIG. 2 shows a 7-year-old tree of the new hazelnut cultivar ‘Thompson’. The photo was taken on Jun. 17, 2022, in the eighth leaf pruned to a single trunk.

FIG. 3 shows immature nuts and husks of ‘Thompson’ and ‘McDonald’ hazelnuts.

FIG. 4 shows nuts, raw kernels, and blanched kernels of hazelnuts of ‘Thompson’ (OSU 1304.039) and ‘McDonald’ hazelnuts. “EFB-Gasaway” indicates that both ‘Thompson’ and ‘McDonald’ carry a dominant allele for eastern filbert blight resistance from ‘Gasaway’, and “S₂ S₁₅” indicates that ‘Thompson’ and ‘McDonald’ carry incompatibility alleles 2 and 15.

FIG. 5 shows the time of female receptivity (bottom, red), pollen shed (top, green), and vegetative budbreak of ‘Thompson’ (OSU 1304.039), ‘McDonald’ and other hazelnut cultivars in Corvallis, OR (December 2018 to March 2019).

FIG. 6 shows the time of female receptivity (bottom, red), pollen shed (top, green), and vegetative budbreak of ‘Thompson’ (OSU 1304.039), ‘McDonald’ and other hazelnut cultivars in Corvallis, OR (December 2019 to March 2020).

FIG. 7 shows the time of female receptivity (bottom, red), pollen shed (top, green), and vegetative budbreak of ‘Thompson’ (OSU 1304.039), ‘McDonald’ and other hazelnut cultivars in Corvallis, OR (December 2020 to March 2021).

SEQUENCE LISTING

The nucleic acid sequences in the accompanying sequence listing are shown using standard letter abbreviations for nucleotide bases as defined in 37 C.F.R. 1.822. Only one strand of each nucleic acid sequence is shown, but the complementary strand is understood as included by any reference to the displayed strand. In the accompanying sequence listing SEQ ID NOS: 1-40 are primer sequences that can be used for genetic fingerprinting (see, Table 7).

DETAILED DESCRIPTION

Certain characteristics of this variety may change with changing environmental conditions (such as photoperiod, temperature, moisture, soil conditions, nutrient availability, or other factors) without, however, any variance in genotype. Color descriptions and other terminology are used in accordance with their ordinary dictionary descriptions unless the context clearly indicates otherwise. The aforementioned photographs and following observations and measurements describe plants grown in Corvallis, OR, outdoors in the field during the spring and summer. The plant used for the photographs and description were from a seven-year-old tree propagated by tie-off layerage and growing on its own roots. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 5^th Edition, 2007 except where general terms of ordinary dictionary significance are used. The color values were determined in spring and summer 2020-2022 under natural light conditions in Corvallis, Oregon. The UPOV descriptor list is from the Mar. 28, 1979 Hazelnut guidelines from UPOV.

BOTANICAL

• Scientific name: Corylus avellana.
• Parentage:
  • • Seed parent.—‘OSU 914.082’ (unpatented breeding selection).
    • Pollen parent.—‘OSU 820.007’ (unpatented breeding selection).
• Incompatibility alleles: ‘Thompson’ has incompatibility alleles S₂ and S₁₅. Hazelnut is a wind-pollinated, monoecious species that exhibits a sporophytic self-incompatibility system controlled by a single locus designated as the S-locus with 33 alleles (Mehlenbacher, J. Amer. Soc. Hort. Sci. 139:191-212, 2014). For comparison, Corylus avellana ‘McDonald’ has the same pair of alleles S₂ and S₁₅, ‘PollyO’ (U.S. Plant Pat. No. 32,459) has alleles S₂ and S₁₀, ‘Sacajawea’ (unpatented, Mehlenbacher et al., HortScience 43:255 257, 2008) has the alleles S₁ and S₂₂, ‘Tonda di Giffoni’ has alleles S₂ and S₂₃, while ‘Tonda Pacifica’ (U.S. Plant Pat. No. 22,715) and ‘Wepster’ have alleles S₁ and S₂.
• Propagation (type rooted suckers):
  • • Time to initiate roots.—About 30 days at 20° C.
    • Time to produce a rooted young plant.—About six months at 22° C.
    • Root description.—Fine to thick; freely branching; creamy white in color.
• Propagation (type whip grafting):
  • • Time to budbreak on the scions.—About 14 days at 25° C.
    • Time to produce a grafted plant.—About six months at 25° C.
• Plant:
  • • Appearance.—Natural habit is perennial shrub, but in commercial orchards, is a single trunk tree. Globose plant habit.
    • Growth and branching habit.—Freely branching; about 15 lateral branches develop per plant. Pinching, that is, removal of the terminal apices, enhances branching with lateral branches potentially forming at every node.
    • Vigor.—Low.
    • Plant height.—About 2.9 m.
    • Plant diameter.—About 3.1 m.
    • Trunk cross section area 30 cm above the soil line.—In a trial planted in Corvallis, Oregon in 2014, trunk cross-sectional area was 46.9 cm² in December 2020. In a second trial planted in Corvallis, OR in 2015, trunk cross-sectional area was 47.0 cm². These values are about 65% of ‘Jefferson’ in the same trials.
    • Trunk color.—RHS 197B.
• Lateral branch:
  • • Length.—19.0-31.0 cm, typically 27.2 cm.
    • Diameter.—3.3-4.5 mm, typically 3.7 mm.
    • Internode length (at base).—About 0.75 cm.
    • Internode length (at tip).—2.4-3.5 cm, typically about 2.8 cm.
    • Texture.—Smooth, pubescent.
    • Strength.—Strong.
    • Color.—Immature: RHS 144A. Mature: RHS 177B. Previous Seasons Branches: RHS 199C.
• Foliage:
  • • Arrangement.—Alternate, simple.
    • Size.—Length: 7.5-11.9 cm, typically about 9.7 cm. Width: 7.4-11.1 cm, typically about 8.8 cm.
    • Shape.—Oblong to ovate.
    • Apex.—Obtuse to acute.
    • Base.—Cordate.
    • Margin.—Serrate.
    • Leaf texture.—Slightly pubescent on upper and lower surfaces.
    • Foliage color.—Developing Foliage: Upper Surface: RHS 141B. Lower Surface: RHS 141C. Fully Expanded Foliage: Upper Surface: spring and summer, RHS 137B; late summer and fall, RHS 137B. Lower Surface: spring and summer, RHS 137D; late summer and fall, RHS 137D.
    • Venation pattern.—Pinnate.
    • Venation color.—Upper Surface: Spring and summer, RHS 145A; late summer and fall, RHS 145A. Lower Surface: Spring and summer, RHS 145A; late summer and fall, RHS 145A.
    • Leaf bud.—Shape: Globular, UPOV Descriptor value-2. Time of Budbreak: Medium, UPOV Descriptor value — 5. ‘Thompson’. budbreak is about 12 days before ‘Jefferson’, 6 days before ‘Felix’, and 6 days later than ‘McDonald’. Color of leaf buds: RHS 144C.
    • Petiole.—Length: 13.0-19.3 mm, typically about 16.3 mm. Diameter: 0.8-1.8 mm, typically about 1.3 mm. Texture: Weakly pubescent (both upper and lower surfaces). Color: RHS 143B (lower surface, early fall).
• Flowers:
  • • Male inflorescences.—Catkins Color Prior to Elongation: RHS 176B exposed to sun, RHS 194C in shade. Catkin Length: 23.5 mm.
    • Female inflorescence style color.—RHS 59A.
    • Female inflorescence stigma color.—RHS 59A.
    • Time of female flowering.—Early-medium, UPOV Descriptor value — 4.
    • Time of female flowering compared to male flowering.—Homogamy, UPOV Descriptor value — 2.
    • Involucre constriction.—Present.
    • Involucre length.—1.3 times length of nut, UPOV Descriptor value — 5.
    • Involucre size of indentation.—Strong, UPOV Descriptor value — 7.
    • Strength of involucre serration of indentation.—Weak, UPOV Descriptor value — 3.
    • Thickness of involucre callus at base.—Thin, UPOV Descriptor value — 3.
    • Pubescence on husk.—Absent, UPOV Descriptor value — 1.
    • Density of hairiness of involucre.—Weak, UPOV Descriptor value — 3.
    • Jointing of involucre bracts.—Absent, UPOV Descriptor value — 1.
    • Involucre color.—RHS 145A for inner and outer surface.
• Nut:
  • • Length.—Average 17.1 mm.
    • Width.—Average 18.6 mm.
    • Depth.—Average 16.8 mm.
    • Nut shape.—Globular, UPOV Descriptor value — 1.
    • Nut shape index.—1.04 ((Width+Depth)/2*Length).
    • Nut compression index.—1.10 (Width/Depth).
    • Nut weight.—2.79 g.
    • Kernel weight.—1.25 g.
    • Kernel percentage.—44.8% (Kernel Weight/Nut Weight).
    • Number of fruits per cluster.—Three to four (see, FIG. 3).
    • Nutshell coloration.—RHS 164A.
    • Number of stripes on shell.—Many, UPOV Descriptor value — 7.
    • Shape of fruit apex.—Slightly prominent, UPOV Descriptor value — 3.
    • Prominence of fruit apex.—Slightly prominent, UPOV Descriptor value — 3.
    • Size of fruit pistil scar on shell.—Small, UPOV Descriptor value — 3.
    • Hairiness of top of fruit.—Weak, UPOV Descriptor value — 3.
    • Curvature of nut basal scar.—Flat, UPOV Descriptor value — 2.
    • Double kernels.—Absent.
    • Kernel apex shape.—Obtuse, UPOV Descriptor value — 2.
    • Kernel base shape.—Rounded, UPOV Descriptor value — 2.
    • Kernel shape.—Globular, UPOV Descriptor value — 1.
    • Shape of kernel in cross-section.—Circular, UPOV Descriptor value — 2.
    • Lateral groove in kernel.—Absent, UPOV Descriptor value — 1.
    • Corkiness of pellicle of kernel.—Slightly corky, UPOV Descriptor value — 3.
    • Color of pellicle.—RHS 165C.
    • Color of kernal after roasting (130° C. for 15 minutes).—RHS 158A.
• Disease/pest resistance: In Oregon, plants of ‘Thompson’ are resistant to EFB caused by the fungus Anisogramma anomala (Peck) E. Müller. All trees of ‘Thompson’ in trial plots have remained free of EFB with no fungicide applications. Fungicide applications are not expected to be needed to control EFB. Plants have not been challenged against all populations of Anisogramma anomala present in North America (Muehlbauer et al., Phytopathology 109:1074-1082, 2019); it is likely that ‘Thompson’ is susceptible to populations of the fungus in New Jersey that are able to overcome resistance derived from ‘Gasaway’. Susceptibility to bacterial blight caused by Xanthomonas arboricola pv. corylina has not been quantified, but no trees in the trials in Corvallis, Oregon were affected. Susceptibility to bud mite (primarily Phytoptus avellanae Nal.) was rated in trials in Corvallis, OR, in mid-December on a scale of 1 (no blasted buds) to 5 (many blasted buds). The average rating for ‘Thompson’ was 1.04, indicating a high level of resistance comparable to ‘Barcelona’ and ‘Jefferson’.
• Temperature tolerance: ‘Thompson’ was selected in Corvallis, OR and is targeted for production in USDA Plant Hardiness Zones 6a to 7b. Plants of the new Corylus avellana have been observed to tolerate temperatures from −18° C. to 40° C.
• Comparative data:
  • • Disease resistance.—Based on field exposure and DNA markers, ‘Thompson’ is resistant to eastern filbert blight (EFB) caused by Anisogramma anomala in Oregon, where cultivars previously widely grown (‘Barcelona’, ‘Ennis’ (unpatented), ‘Daviana’, and ‘Butler’ (unpatented)) are susceptible. The more recently developed cultivars ‘Santiam’, ‘Yamhill’, ‘Jefferson’, ‘Dorris’, ‘Wepster’, and ‘McDonald’ and their associated pollinizers are protected from EFB by a single resistance gene from Corylus avellana ‘Gasaway’. This gene provides a high level of resistance in Oregon and Washington where the diversity of the fungus is limited (Muehlbauer et al., Phytopathology 109:1074-1082, 2019), but does not provide a similar level of protection from disease in the eastern U.S. where the pathogen is endemic and genetically diverse (Capik and Molnar, J. Amer. Soc. Hort. Sci. 137:157-172, 2012; Molnar et al., Plant Dis. 10:1265, 2010; Muehlbauer et al., Phytopathology 109:1074-1082, 2019). It is unlikely that ‘Thompson’ would remain free of EFB in New Jersey where populations of the pathogen are genetically diverse.
    • Nut and kernel characteristics.—‘Thompson’ hazelnut is targeted for the blanched kernel market and specifically for nut production in the Pacific Northwestern United States in USDA Plant Hardiness Zones 6a to 7b. As shown in FIGS. 3 and 4, the nut shape and kernel shape are round. The average single nut weight for ‘Thompson’ over four years (2017-20) is 2.79 g, average single kernel weight is 1.25 g, with an average kernel percentage of 44.8% (see, Table 3). Nut weight in the same trial was 3.86 g for ‘Jefferson’, 2.70 g for ‘McDonald’ and 2.43 g for ‘Wepster’. Kernel weights in the same trial were 1.74 g for ‘Jefferson’, 1.41 g for ‘McDonald’ and 1.13 g for ‘Wepster’. Kernel percentage in the same trial was 45.0% for ‘Jefferson’, 52.2% for ‘McDonald’ and 46.7% for ‘Wepster’. ‘Thompson’ nuts and kernels are significantly smaller than those of ‘Barcelona’ and ‘Jefferson’, and intermediate between ‘McDonald’ and ‘Wepster’. In the trial planted in 2014 in Corvallis, OR, the trees produced a few nuts in 2016, but were not harvested. Nuts were harvested for four years (2017-20), dried, weighed and evaluated. Total nut weight per tree (2017-20) was 14.7 kg for ‘Thompson’, compared to the checks ‘Jefferson’ (18.3 kg), ‘McDonald’ (18.6 kg) and ‘Wepster’ (21.8 kg). Trunk cross-sectional area (TCA) was 46.89 cm2, or 66% of ‘Jefferson’. Yield efficiency, the ratio of total yield to TCA, was a very high 0.315 kg/cm² and higher than all three checks. Trees have a globose growth habit, and lower vigor than all other selections in the Corvallis trial. — Raw kernels of ‘Thompson’ have a light brown pellicle with little attached fiber (average rating was 2.19 on a scale of 1 (no fiber) to 4 (much fiber); see, Table 3). Pellicle removal after roasting at 150° C. for 15 min and rubbing is rated on a scale of 1 (complete pellicle removal) to 7 (no pellicle removal). Most of the pellicle on ‘Thompson’ kernels is removed after roasting with an average rating of 2.75 (see, Table 3), a value slightly better than ‘McDonald’ (3.50) and ‘Wepster’ (3.03). — The average percentage of good kernels (kernels free of defects) for ‘Thompson’ in the trial planted in 2014 was 83.2% (see, Table 3). There was on average 4.2% blank nuts, 2.8% moldy kernels, 1.6% nuts with shriveled kernels, and 7.4% poorly filled nuts. The percentage of good kernels for ‘Thompson’ was considerably higher than the 60-70% range in multiple reports for ‘Barcelona’ in Oregon. The percentage of poorly filled nuts for ‘Thompson’ (7.4%) was lower than for ‘Jefferson’ (12.6%) and ‘Wepster’ (17.3%) despite the heavy crop loads on ‘Thompson’ trees.
    • Nut maturity date.—The nuts of ‘Thompson’ are typically borne in clusters of 3-4 in husks about 30% longer than the nuts (see, FIG. 3). The husks open as they dry at maturity. About 92% of the nuts fall free of the husk at maturity and the other 8% of the nuts come out of the husks as they moved through the harvester. When mature, the shells are tan in color. Estimates recorded at the time of harvest in the two trials indicate that ‘Thompson’ nuts mature about 3 days before ‘Barcelona’, 6 days before ‘Jefferson’, 7 days after ‘Wepster’, and 10 days after ‘McDonald’.
    • Flowering time.—Trees of ‘Thompson’ set a high number of catkins that shed copious amounts of pollen. Time of pollen shed and female receptivity were recorded weekly from mid-December to mid-March in the second trial for three years for ‘Thompson’ and the check cultivars (see, FIGS. 5-7). The female inflorescences of ‘Thompson’ emerge early and are fully receptive in mid-January, with ‘McDonald’, but their styles blacken about two weeks earlier than those of ‘McDonald’. Female receptivity dates are similar for ‘Wepster’, ‘Yamhill’, ‘York’ and ‘PollyO’. Pollen is shed by ‘Thompson’ in early mid-season, with ‘McDonald’ and before ‘Felix’. Pollen has been collected and used in several controlled pollinations, and both quantity and viability appear to be very good. Pollen germination tests over three years (2018-2020) showed good germination for ‘Thompson’. On Jan. 23, 2020, pollen germination of ‘Thompson’ was 79% in contrast to 40% for ‘Barcelona’ while values for other cultivars ranged from 69 to 91%. On Jan. 30, 2019, pollen germination of ‘Thompson’ was 76% and similar to ‘PollyO’ (72%), ‘Sacajawea’ (82%) and ‘Yamhill’ (72%). Pollen germination tests on five dates in January 2018 showed good germination for ‘Thompson’ (65%), ‘PollyO’ (77%), ‘Sacajawea’ (73%) and ‘Yamhill’ (81%), and much lower germination for ‘Barcelona’ (40%). When establishing a new orchard, the inclusion of at least three pollinizers with the main cultivar is encouraged.
    • Additional comparative descriptors.—Tables 1-6 provide additional descriptors and trial data distinguishing ‘Thompson’ from various hazelnut varieties.
    • Microsatellite marker analysis.—Twenty microsatellite (simple sequence repeat) markers were used. PCR products were multiplexed post-PCR and sized using capillary electrophoresis. See, for example, Bassil et al., Acta Horticulturae 686:105-110, 2005; Gökirmak et al., Genetic Resources and Crop Evolution 56:147-172, 2009; Gürcan and Mehlenbacher. Molecular Breeding 26:551-559, 2010; Gürcan et al. Tree Genetics and Genomes 6:513-531, 2010). The microsatellite markers are described in Table 7 and allele sizes are reported in Table 8.

TABLE 1
Nut yield, trunk cross-sectional area (TCA), yield efficiency,
and bud mite ratings of ‘Thompson’ in comparison with
other hazelnut cultivars and selections in the
first trial, planted in 2014. Randomized complete
block design with four blocks and
a single tree of each selection in each block.
Yield is in kg per tree. Trunk cross-sectional area (TCA)
is in cm2. Yield efficiency is in kg/cm2. Bud mite ratings
are from 1 (no blasted buds) to 5 (many blasted buds).
	Nut Yield (kg)
Selection	2017	2018	2019	2020	Total
‘541.147’	0.367	2.875	4.758	3.670	11.669
‘Thompson’	1.784	2.945	3.623	6.353	14.704
‘Jefferson’	2.389	4.765	4.596	6.585	18.335
‘McDonald’	0.782	3.895	5.858	8.323	18.857
‘Wepster’	2.161	4.590	5.325	9.695	21.771
LSD (0.05)	0.581	0.948	1.114	1.395	2.551
		Yield
Selection	TCA	efficiency	BBM
‘541.147’	71.13	0.1647	3.4
‘Thompson’	46.89	0.3151	1.0
‘Jefferson’	71.22	0.2581	1.2
‘McDonald’	79.59	0.2386	2.0
‘Wepster’	77.33	0.2867	1.5
LSD (0.05)	13.34	0.0448	0.2

TABLE 2
Nut weight, kernel weight, percent kernel, and ratings
for fiber and blanching (pellicle removal) of
‘Thompson’ in comparison with other hazelnut
cultivars and selections in the first trial,
planted in 2014. Randomized complete
block design with four blocks and a single
tree of each selection in each block.
	10-	10-	Percent
Selection	NutWt	KerWt	kernel
‘541.147’	26.46	11.72	44.32
‘Thompson’	27.88	12.48	44.77
‘Jefferson’	38.64	17.37	44.99
‘McDonald’	26.96	14.05	52.15
‘Wepster’	24.27	11.34	46.73
LSD (0.05)	0.70	0.34	0.52
Selection	Fiber	Blanch
‘541.147’	3.78	4.50
‘Thompson’	2.19	2.75
‘Jefferson’	2.84	4.06
‘McDonald’	2.59	3.50
‘Wepster’	2.75	3.03
LSD (0.05)	0.20	0.24

TABLE 3
Frequency of good nuts and of nut and kernel
defects in ‘Thompson’ and other hazelnut
cultivars from the first replicated trial,
planted in 2014, with 4 trees per selection.
Percentages of good nuts and
nut kernel defects are averaged over four
years (2017-2020).
				Brown
	Selection	Good	Blank	Stain	Moldy
	‘541.147’	86.76	8.26	0.18	0.32
	‘Thompson’	83.18	4.18	0.56	2.82
	‘Jefferson’	77.76	3.82	1.62	2.06
	‘McDonald’	84.38	3.26	0.44	2.00
	‘Wepster’	73.82	6.00	0.12	1.00
	LSD (0.05)	3.37	1.63	0.85	1.09
			Poor		Black
	Selection	Shrivel	Fill	Twin	Tip
	‘541.147’	1.88	2.50	0.12	0.00
	‘Thompson’	1.56	7.38	0.18	0.38
	‘Jefferson’	1.44	12.62	0.62	1.00
	‘McDonald’	4.62	5.00	0.06	0.26
	‘Wepster’	0.76	17.26	0.06	1.06
	LSD (0.05)	1.31	2.35	0.52	0.66

TABLE 4
Performance of hazelnut selections from the second
replicated trial planted in 2015. Trunk
cross-sectional area (TCA), annual and cumulative
field-run nut yield, and yield efficiency of selections
over four years (2018 - 2021). 7 trees per cultivar.
		TCA	Field-run nut yield (kg/tree)
	Selectionz	(cm2)	2018	2019	2020	2021
	‘Thompson’	47	1.76	2.71	3.54	6.09
	‘Felix’	122	1.00	2.81	3.93	6.96
	‘Jefferson’	74	3.00	4.66	4.51	8.93
	‘McDonald’	81	1.20	4.10	6.00	8.43
	‘Theta’	123	0.57	2.11	0.59	3.64
	LSD (.05)	16	0.43	0.82	0.92	1.06
		Total field-run	Yield efficiency
		yield (kg/tree)	(total kg/cm2)
	Selectionz	Nut	Kernel	Nut	Kernel
	‘Thompson’	14.10	6.20	0.30	0.13
	‘Felix’	14.70	7.47	0.12	0.06
	‘Jefferson’	21.11	9.38	0.29	0.13
	‘McDonald’	19.73	10.26	0.24	0.13
	‘Theta’	6.91	3.52	0.06	0.03
	LSD (.05)	2.33	1.07	0.03	0.02

TABLE 5
Nut weight, kernel weight, kernel
percentage, and rating
for blanching (pellicle removal)
of ‘Thompson’ and 4 other
hazelnut cultivars in the
second replicated trial planted
in 2015.7 trees per cultivar.
		Nut	Kernel	Percent
	Selectionz	weight (g)	weight (g)	kernel	Blanch
	‘Thompson’	2.5	1.1	44	2.4
	‘Felix’	2.5	1.2	51	2.2
	‘Jefferson’	3.4	1.5	44	4.6
	‘McDonald’	2.4	1.2	52	3.2
	‘Theta’	2.1	1.0	50	2.6
	LSD (.05)	0.15	0.1	1.5	0.3

TABLE 6
Frequency of good nuts, and of nut and kernel
defects of ‘Thompson’ in comparison with
other hazelnut cultivars and
selections in the second trial, planted in 2015.
	Frequency (%)
			Brown		Usable
Selectionz	Good	Blanks	Stain	Mold	Shrivel
‘Thompson’	96.0	2.0	0.1	0.8	0.7
‘Felix’	95.0	4.0	0.0	0.1	0.7
‘Jefferson’	96.0	3.1	0.0	0.5	0.8
‘McDonald’	97.0	2.1	0.1	0.5	2.3
‘Theta’	95.0	4.6	0.0	0.1	0.2
LSD (.05)	2.0	2.8	0.2	0.9	1.3
	Frequency (%)
		Usable
		Poor	Poor		Black
Selectionz	Shrivel	Fill	Fill	Twin	Tip
‘Thompson’	0.7	1.6	0.2	0.04	0.2
‘Felix’	0.8	0.7	0.3	0.2	0.1
‘Jefferson’	0.2	0.6	0.1	0.5	0.1
‘McDonald’	0.5	1.0	0.1	0.0	0.1
‘Theta’	0.1	0.7	0.1	0.1	0.04
LSD (.05)	0.8	3.9	1.2	0.7	0.4

TABLE 7
Primers and annealing temperatures for the microsatellite marker loci used for fingerprinting
hazelnut cultivars. Allele size = range of sizes; Primers, forward (F, listed first; 5'-3')
and reverse (R, second, 5'-3') (HEX and FAM are dyes); Tm = Annealing temperature;
n = Number of alleles; He = expected heterozygosity; Ho = observed heterozygosity; PIC =
Polymorphism information content; r = frequency of null alleles;
LG = linkage group (S is susceptible female parent 'OSU 252.146';
R is resistant parent 'OSU 414.062'); Reference is the journal article where additional
details were published (Gurcan et al., Tree Genetics and Genomes 6:513-531, 2010;
Gürcan and Mehlenbacher, Molecular Breeding 26:551-559, 2010; Bassil, et
al., Acta Horticulturae 686:105-110, 2005; and Gökirmak, et al.
Genetic Resources and Crop Evolution 56:147-172, 2009).
	All-	Primer	Primer	Tm
	ele	(SEQ	(SEQ	(°							Refer-
Locus	sizes	ID NO)	ID NO)	C.)	n	He	Ho	PIC	r	LG	ence
A613	149-	Ned-	R-	60	14	0.86	0.85	0.85	0.00	11R	Gurcan
	177	CACACGC	CCCCTTT								et al.,
		CTTGTC	CACATG								2010
		ACTCTTT	TTTGCTT
		(1)	(2)
A614	125-	Hex-	R-	60	14	0.85	0.85	0.84	0.00	6S,	Gurcan
	156	TGGCAGA	GCAGTGG							6R	et al.,
		GCTTTG	AGGAT								2010
		TCAGCTT	TGCTGACT
		(3)	(4)
A616	136-	Fam-	R-	60	13	0.85	0.85	0.83	0.00	8R	Gurcan
	162	CACTCAT	ATGGCTT								et al.,
		ACCGCA	TTGCTT								2010
		AACTCCA	CGTTTTG
		(5)	(6)
A640	354-	F-	Fam-	67	11	0.80	0.73	0.77	0.04	10R	Gurcan
	378	TGCCTCT	CGCCATA								et al.,
		GCAGTT	TAATTG								2010
		AGTCAT	GGATGC
		CAAATGT	TTGTTG
		AGG (7)	(8)
B617	280-	Fam-	R-	60	9	0.80	0.78	0.78	0.01	8S,	Gurcan
	298	TCCGTGT	TGTTTT							8R	et al.,
		TGAGTA	TGGTGGA								2010
		TGGACGA	GCGATG
		(9)	(10)
B619	146-	Fam-	R-	60	14	0.88	0.88	0.87	0.00	3S,	Gurcan
	180	AGTCGGC	GCGATCT							3R	et al.,
		TCCCCT	GACCTC								2010
		TTTCTC	ATTTTTG
		(11)	(12)
B634	218-	Hex-	R-	60	9	0.76	0.76	0.73	0.00	4R	Gurcan
	238	CCTGCA	GTGCAG								et al.,
		TCCAGG	AGGTTG								2010
		ACTCATTA	CACTCAAA
		(13)	(14)
B657	210-	Ned-	R-	60	8	0.84	0.98	0.82	-0.08	11S,	Gurcan
	228	GAGAGTG	AGCCTCA							11R	et al.,
		CGTCTT	CCTCCA								2010
		CCTCTGG	ACGAAC
		(15)	(16)
B671	221-	Hex-	R-	60	13	0.86	0.88	0.84	-0.01	9S,	Gurcan
	249	TTGCCA	ACCAGC							9R	et al.,
		GTGCATA	TCTGGG								2010
		CTCTGATG	CTTAACAC
		(17)	(18)
B709	219-	Ned-	R-	60	8	0.74	0.76	0.70	-0.01	5S,	Gurcan
	233	CCAAGC	GCGGGT							5R	et al.,
		ACGAAT	TCTCGTT								2010
		GAACTCAA	GTACACT
		(19)	(20)
B733	161-	Ned-	R-	60	8	0.68	0.68	0.63	0.00	7S,	Gurcan
	183	CACCCT	CATCCC							2R	et al.,
		CTTCACC	CTGTTGG								2010
		ACCTCAT	AGTTTTC
		(21)	(22)
B749	200-	Hex-	R-	60	6	0.60	0.64	0.51	-0.03	1R	Gurcan
	210	GGCTGA	TCGGCTA								et al.,
		CAACAC	GGGTTA								2010
		AGCAGAAA	GGGTTTT
		(23)	(24)
B751	141-	Fam-	R-	60	7	0.80	0.78	0.77	0.01	7S,	Gurcan
	153	AGCTGGT	AAACTC							2R	et al.,
		TCTTCG	AAATAA								2010
		ACATTCC	AACCCC
		(25)	TGCTC
			(26)
B774	195-	Ned-	R-	60	8	0.80	0.80	0.77	0.00	5S,	Gurcan
	213	GTTTTG	TGTGTGT							5R	et al.,
		CGAGCTC	GGTCTG								2010
		ATTGTCA	TAGGCACT
		(27)	(28)
C115	167-	Fam-	R-	60	10	0.84	0.90	0.82	-0.035	4S,	Bassil
	225	CATTTT	GTTTCC							4R	et al.,
		CCGCAGA	AGATCTG								2005b;
		TAATACAGG	CCTCCA								Gokirmak
		(29)	TATAAT								et al.,
			(30)								2009
KG807	226-	F-	Fam-	54	4	0.67	0.78	0.60	-0.07	11	Gurcan
	248	AAGCAA	CTTACA								and
		GAAAGG	GATAAAT								Mehlen-
		GATGGT	GGCTCAAA								bacher,
		(31)	(32)								2010
KG809	333-	F-	Hex-	55	5	0.66	0.64	0.60	0.01	4	Gurcan
	345	GGAAGG	AGGCAT								and
		TGAGAG	CAGTTC								Mehlen-
		AAATCAAGT	ATCCAA (34)								bacher,
		(33)									2010
KG811	240-	F-	Ned-	58	12	0.83	0.82	0.81	0.01	2	Gurcan
	278	GAACAA	AAGGCG								and
		CTGAAG	GCACTC								Mehlen-
		ACAGCAAAG	GCTCAC (36)								bacher,
		(35)									2010
KG827	264-	Fam-	R-	67	9	0.78	0.84	0.75	-0.04	9	Gurcan
	282	AGAACT	GAGGGA								and
		CCGACT	GCAAGT								Mehlen-
		AATAATC	CAAAGT								bacher,
		CTAACC	TGAGAA								2010
		CTTGC (37)	GAAA (38)
KG830	279-	Ned-	R-	67	9	0.79	0.78	0.76	0.00	9	Gurcan
	311	TGGAGGA	AAAGCA								and
		AGTTTT	ACTCAT								Mehlen-
		GAATGG	AGCTGA								bacher,
		TAGTAG	AGTCCA								2010
		AGGA (39)	ATC (40)A

TABLE 8
Allele sizes at 20 microsatellite markers in ‘Thompson’,
its parents ‘OSU 914.082’ and ‘OSU 820.007’, and ten other
cultivars. The same microsatellite markers were used to
fingerprint ‘OSU 541.147’ (US PP33,561) in 2020 and
‘PollyO’ in 2018. ‘Thompson’ is easily distinguished
from all others as shown in the table below.
		‘OSU	‘OSU
Marker	‘Thompson’	914.082’	820.007’
A613	151/153	151/169	153/161
A614	158/158	150/158	132/158
A616	152/152	152/152	152/160
A640	362/362	362/374	362/362
B617	285/293	285/293	285/293
B619	158/158	158/166	158/166
B634	222/228	222/228	228/236
B657	218/226	218/226	218/224
B671	239/243	239/239	243/243
B709	229/229	229/229	229/229
B733	173/185	173/181	181/185
B741	181/190	181/190	181/181
B749	216/216	216/216	216/216
B751	144/null	144/144	152/null
B774	209/220	209/220	209/209
C115	174/194	174/194	174/194
KG807	242/252	242/252	242/252
KG809	339/342	339/342	339/342
KG811	257/267	267/267	251/257
KG827	270/270	270/272	NA
Marker	‘Barcelona’	‘Gasaway’	‘McDonald’
A613	153/161	161/163	153/169
A614	125/132	143/158	135/158
A616	144/152	150/150	150/160
A640	354/374	362/368	362/368
B617	285/289	291/295	293/295
B619	158/172	172/176	158/172
B634	228/228	222/234	222/228
B657	218/222	224/228	210/218
B671	225/229	237/249	229/237
B709	227/235	229/229	229/229
B733	173/175	175/175	173/175
B741	181/190	190/192	181/192
B749	216/216	214/216	214/216
B751	144/154	144/144	144/144
B774	209/213	209/215	209/220
C115	174/194	214/218	174/198
KG807	238/252	242/252	252/252
KG809	339/339	339/348	339/339
KG811	261/267	257/261	245/267
KG827	282/284	272/282	272/284
Marker	‘Montebello’	‘PollyO’	‘Santiam’
A613	151/153	153/167	151/153
A614	125/132	125/158	132/158
A616	152/160	144/152	150/152
A640	362/374	354/354	362/362
B617	285/293	285/295	285/295
B619	160/166	158/166	158/166
B634	232/236	228/236	222/236
B657	218/226	218/218	218/226
B671	225/243	229/249	225/237
B709	229/235	223/227	229/229
B733	175/185	175/181	175/181
B741	181/190	168/188	190/192
B749	216/216	216/216	216/216
B751	154/154	144/154	144/144
B774	209/213	209/209	215/220
C115	174/198	194/214	194/198
KG807	238/242	238/252	242/252
KG809	339/348	342/342	339/342
KG811	251/267	261/267	257/267
KG827	282/282	272/284	272/272
	‘T.G.d.
Marker	Langhe’	‘T. Romana’	‘Wepster’
A613	153/153	153/177	159/167
A614	125/135	125/161	135/158
A616	150/152	150/152	152/160
A640	368/368	372/372	368/374
B617	285/295	285/291	293/295
B619	150/166	158/178	166/172
B634	228/228	222/232	228/228
B657	218/226	218/224	226/226
B671	239/243	229/239	239/249
B709	229/229	227/227	229/235
B733	173/175	175/179	173/175
B741	181/188	168/199	181/190
B749	216/216	216/216	214/216
B751	150/154	144/154	144/144
B774	209/217	209/215	209/213
C115	174/174	174/198	194/194
KG807	238/252	238/242	252/252
KG809	339/342	339/342	342/342
KG811	257/267	267/267	257/257
KG827	270/270	268/284	270/282
		Marker	‘Yamhill’
		A613	153/163
		A614	132/158
		A616	150/150
		A640	354/368
		B617	289/295
		B619	158/172
		B634	236/236
		B657	218/228
		B671	225/243
		B709	229/229
		B733	181/185
		B741	181/190
		B749	216/216
		B751	152/152
		B774	209/217
		C115	198/214
		KG807	230/252
		KG809	348/348
		KG811	251/261
		KG827	282/282

Claims

1. A new and distinct variety of Corylus avellana plant, substantially as illustrated and described herein.