Patent Grant
PP28200
Botanical denomination: Corylus avellana cultivar.
Variety designation: ‘McDonald’.
The present Invention relates to a new and distinct cultivar of Corylus plant, botanically known as Corylus avellana, and hereinafter referred to by the name ‘McDonald’.
The new Corylus resulted from a controlled cross of female parent ‘Tonda Pacifica’ (U.S. Plant Pat. No. 22,715) and male parent ‘Santiam’ (unpatented) made in 1997. Hybrid seeds from the cross were harvested in August 1997, stratified, and seedlings grown in the greenhouse during the summer of 1998. From this cross, a total of 132 seedling trees were planted in the field in Corvallis in October, 1998. ‘McDonald’ was discovered and selected as a single plant within the progeny of the stated cross-pollination in a controlled environment in Corvallis, Oreg., USA. It was originally assigned the designation OSU 880.027, which indicates the row and tree location of the original seedling.
‘Tonda Pacifica’ (OSU 228.084) was released in 2010 (Mehlenbacher et al., 2011), is from a cross of ‘Tonda Gentile delle Langhe’×OSU 23.024 (=‘Barcelona’בExtra Ghiaghli’). ‘Santiam’ (Mehlenbacher et al., 2007), released in 2005, carries a dominant allele for a very high level of resistance to eastern filbert blight (EFB) from ‘Gasaway’ (unpatented). ‘Tonda Gentile delle Langhe’ (unpatented), the female parent of ‘Tonda Pacifica’, is an important cultivar in Piemonte, northern Italy. ‘Barcelona’ (unpatented), Oregon's most widely planted hazelnut cultivar, is known as ‘Castanyera’ where it originated in Catalunya, Spain. ‘Extra Ghiaghli’ (unpatented), obtained from Greece, is a clone of the important Turkish cultivar ‘Tombul’. ‘Gasaway’ (unpatented) is the source of a single dominant gene for resistance to eastern filbert blight.
The new cultivar was asexually reproduced by rooted suckers annually for nine years (2004-2005, 2007-2013) in Corvallis, Oreg. The new cultivar was also asexually propagated by whip grafting in 2005 in Corvallis, Oreg. The unique features of this new Corylus are stable and reproduced true-to-type in successive generations of asexual reproduction.
The following traits have been observed and are determined to be the unique characteristics of ‘McDonald’. These characteristics in combination distinguish ‘McDonald’ as a new and distinct cultivar:
Comparisons in two replicated trials conducted in Corvallis, Oreg., plants of the new Corylus differed from plants of the Corylus avellana cultivar ‘Barcelona’ and other cultivars and selections of Corylus avellana known to the Inventors primarily in nut size, nut shape, kernel percentage (ratio of kernel weight to nut weight), frequency of defects (blank nuts, moldy kernels, twins, etc.), time of pollen shed, time of nut maturity, length of the husk or involucre, and plant size. For example:
‘McDonald’ is well-suited to the blanched kernel market for use in chocolate products and baked goods. ‘McDonald’ combines high nut yield, early nut maturity, small round nuts and kernels, high kernel percentage, good kernel blanching and excellent flavor. The tree is moderately vigorous and has a desirable growth habit.
DNA markers and field observations indicate that ‘McDonald’ has a very high level of resistance to eastern filbert blight (EFB) caused by the fungus Anisogramma anomala (Peck) E. Müller. The resistance is conferred by a dominant allele from ‘Gasaway’. EFB is now present throughout the Willamette Valley where 99% of the U.S. hazelnut crop is grown. Pruning to remove cankers and fungicide applications are currently used to manage the disease in orchards of ‘Barcelona’ and other susceptible cultivars. Thus, ‘McDonald’ is suitable for planting in areas with high disease pressure, as are previous releases ‘Santiam’ (2005), ‘Yamhill’ (2008, unpatented), ‘Jefferson’ (2009, unpatented), ‘Dorris’ (2012, U.S. Plant Pat. No. 25,022) and ‘Wepster’ (2013, U.S. Plant Pat. No. 27,141). ‘Wepster’, released as a cultivar in 2013, is cross-compatible with ‘McDonald’ in both directions. Thus ‘Wepster’ and ‘McDonald’ can be planted together with each serving as a pollinizer for the other.
The accompanying colored photographs illustrate the overall appearance of the new cultivar, showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Foliage colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Corylus.
The cultivar ‘McDonald’ has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature and light intensity, without, however, any variance in genotype. The aforementioned photographs and following observations and measurements describe plants grown in Corvallis, Oreg. under commercial practice outdoors in the field during the fall, winter and spring. Plants used for the photographs and description were propagated by tie-off layerage and growing on their own roots, and seven or eight years old. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 1966 Edition, except where general terms of ordinary dictionary significance are used. The list of UPOV descriptors are from the Mar. 28, 1979 Hazelnut guidelines from UPOV.
Tree size, growth habit, yield, and yield efficiency Tree sizes in the two trials were estimated by measuring trunk diameters 30 cm above the soil line, at the end of the 7th growing season (December 2012 and 2013, respectively). Trunk cross-sectional area (TCA) was calculated from trunk diameter. Trees of ‘McDonald’ are moderately vigorous, and their upright-spreading growth habit should be grower-friendly (easy to manage).
In the first trial (Table 1), TCA of ‘McDonald’ (86.9 cm2) was similar to ‘Jefferson’ (unpatented), ‘Dorris’, and ‘York’ (U.S. Plant Pat. No. 24,972). Trees were larger than ‘Yamhill’ (unpatented) but smaller than ‘Wepster’. Total nut yield per tree was 17.11 kg, which is slightly less than ‘Jefferson’, ‘Yamhill’ and ‘Wepster’ and about the same as ‘Dorris’ and ‘Sacajawea’ (unpatented). Nut yield efficiency of ‘McDonald’ (0.198 kg/cm2) was similar to ‘Sacajawea’ and ‘Wepster’, and lower than ‘Jefferson’ and ‘Yamhill’.
In the second trial (Table 1), trees of ‘McDonald’ were similar in size to ‘Jefferson’. In adjacent rows planted at the same time to EFB-susceptible selections, TCAs for ‘Barcelona’, ‘Lewis’ and ‘Clark’ were 138.6, 77.6 and 63.7 cm2, respectively. The TCA of ‘McDonald’ is 63% of ‘Barcelona’. In previous trials, tree size of ‘Jefferson’ and ‘Lewis’ has been about 70% of ‘Barcelona’. Growers have been pleased with this level of vigor. Total nut yield per tree was 21.43 kg for ‘McDonald’ vs. 22.99 kg for ‘Jefferson’, 16.88 kg for the pollinizer ‘Felix’ (U.S. Plant Pat. No. 24,973), and 17.68 kg for ‘Santiam’. Nut yield efficiency for ‘McDonald’7 (0.245 kg/cm2), which adjusts for differences in tree size, was similar to ‘Santiam’ (0.267 kg/cm2), lower than ‘Jefferson’ (0.299 kg/cm2) and higher than ‘Felix’ (0.133 kg/cm2).
zTrunk cross-sectional area calculated from trunk diameters measured in late fall at the end of the seventh season.
yYield efficiency = Total nut yield/TCA.
A high percentage of the nuts and kernels of ‘McDonald’ in both trials were marketable (Table 2). Very few moldy kernels were observed in ‘McDonald’, in striking contrast to ‘Santiam’.
zMeans of years 4-7.
Percent kernel (the ratio of kernel weight to nut weight) for ‘McDonald’ (52%) is higher than ‘Barcelona’ (typically 43%) and ‘Jefferson’ (45%) (Table 3). Yields of kernels per acre would be high for ‘McDonald’. Although ‘McDonald’ is not the highest-yielding selection, its yields have been consistently good and the nuts consistently well-filled. In contrast, ‘Yamhill’ trees occasionally set very heavy nut crops, and the nuts can be so poorly filled that the kernels are not marketable.
zMeans for nuts and kernels are over four years.
yAmount of fiber on the pellicle was rated in the second trial from 1 (none) to 4 (much).
xBlanching was rated from 1 (complete pellicle removal) to 7 (no pellicle removal).
wSusceptibility to bud mite (primarily Phytoptus avellanae Nal.) was rated on four trees of each selection in the second trial on a scale of 1 (no blasted buds) to 5 (many blasted buds). Shown are mean ratings for 5 years (2009-2013).
Nut maturity date. The nuts of ‘McDonald’ are borne in clusters of 2-3 in husks about 50% longer than the nuts. The husks are slit down the side, and flare open as they dry at maturity. About 95% of the nuts fall free of the husk at maturity (range 85-100%). The other 5% of the nuts would come out of the husks as they moved through the harvester. When mature, the shells are light tan in color. Harvest date is estimated to be 14 days before ‘Barcelona’, allowing it to be harvested before the start of the rainy season (Table 4 and
zEstimated percentage of nuts on the ground as opposed to in the tree.
yOf the nuts on the ground, estimated percentage free of the husk.
Nuts in the first trial were annually raked and fed through a Mave harvester. Nuts in the second trial were hand-harvested and notes recorded at the time of harvest (Table 4). Notes included the date, the percentage of nuts on the ground (as opposed to in the tree), and the percentage of the nuts on the ground that were free of the husk (as opposed to inside the husk). We harvest more than 2000 trees by hand every fall, visiting a block once every 7 to 10 days, and harvesting a tree if >70% of the nuts are on the ground. Thus the percentages are estimates. The harvest dates and percentage down indicate that maturity of ‘McDonald’ is about 14 days earlier than ‘Barcelona’ (Table 4). To more precisely estimate nut maturity, the four trees of ‘McDonald’ in the second trial and four trees of ‘Barcelona’ in adjacent rows were harvested by hand at weekly intervals in the final year of the trial (2013). The maturity curves from the 2013 harvest (
Nut and kernel characteristics: ‘McDonald’ can be used in the blanched kernel market as a companion for ‘Wepster’ and an alternative to ‘Yamhill’, ‘Lewis’, ‘Clark’ and ‘Sacajawea’. ‘McDonald’, like ‘Wepster’ and ‘Yamhill’, has a very high level of EFB resistance, while ‘Lewis’, ‘Clark’ and ‘Sacajawea’ have lower level of quantitative resistance. The nut shape is round with a slight point, which lends itself well to sizing and cracking. The shells are thin and easy to crack, and most kernels remain whole when the shell is broken. The kernel size of ‘McDonald’ is small, similar to ‘Clark’, and larger than ‘Wepster’. Raw kernels are attractive and have a light brown pellicle with a moderate amount of attached fiber (rating =2.6) on a scale of 1 (no fiber) to 4 (much fiber). Pellicle removal is rated on a scale of 1 (complete pellicle removal) to 7 (no pellicle removal), with ratings <4.0 being desired. Most of the pellicle on ‘McDonald’ kernels is removed from the kernels with dry heat in the blanching process (ratings=3.8 and 3.3 in the first and second trials, respectively) which is better than ‘Yamhill’ (rating=5.0). Kernel texture, flavor and aroma are excellent, and desirable for use in baked goods and chocolate products.
In two trials, ‘McDonald’ produced fewer nut and kernel defects (and more good kernels) than ‘Barcelona’ in adjacent rows. The nut and kernel data were similar in the two trials. The frequency of moldy kernels in ‘McDonald’ in the two trials was very low (1.0-2.1%) in contrast to ‘Jefferson’ (4.4-5.7%) and especially ‘Santiam’ (7.89-17.3%). Kernel mold is a problem in ‘Lewis’ and ‘Santiam’, particularly when weather is cool and wet in spring and early summer. The frequency of poorly filled nuts is low compared to other selections, even though ‘McDonald’ crops consistently well.
Incompatibility and pollinizers. The trees set a moderate to high amount of catkins that shed copious amounts of pollen in early mid-season, with ‘Wepster’, ‘York’ and ‘Yamhill’. Pollen has been collected and used in several controlled pollinations, and both quantity and viability appear to be very good. ‘McDonald’ has incompatibility alleles S2 and S15 as determined by fluorescence microscopy. Both alleles are expressed in the females, but only S15 is expressed in the pollen because of dominance. By convention, alleles expressed in the pollen are underlined.
Time of pollen shed and female receptivity were recorded weekly from early December 2011 to late March 2013 (
Pests and diseases. Based on DNA marker data, ‘McDonald’, like ‘Wepster’ and ‘Yamhill’, has a very high level of resistance to EFB conferred by a dominant allele from ‘Gasaway’, so fungicide applications are not needed. RAPD markers 152-800 and 268-580 that flank the resistance allele in ‘Gasaway’ are present in ‘McDonald’, and these markers are transmitted to its seedlings. Additional RAPD markers linked to resistance are also present. Trees of ‘McDonald’ have not yet been challenged with the EFB pathogen in glasshouse or structure inoculations. No cankers have been observed on the 11 trees of ‘McDonald’ in the yield trials, while several cankers have been noted on adjacent trees of susceptible genotypes.
Susceptibility to bacterial blight caused by Xanthomonas campestris pv. corylina has not been quantified, but no trees in the two trials were affected.
Susceptibility to big bud mite (primarily Phytoptus avellanae Nal.) was rated in the second trial (Table 3) after leaf fall once per year for five years (December 2009-2013). The scale was from 1 (no blasted buds) to 5 (many blasted buds). The average ratings indicate adequate resistance for ‘McDonald’ (1.8), ‘Jefferson’ (1.2), ‘Felix’ (2.0) and ‘Santiam’ (2.2). Blasted buds are very rare on ‘McDonald’, so chemical applications should not be necessary to control bud mite.
Propagation: Layers of ‘McDonald’ are moderately vigorous and root well, but have lower vigor and caliper than those of ‘Jefferson’ and ‘Barcelona’.
DNA Fingerprinting: Primers used are shown in Table 5, and results shown in Table 6.
This invention was made with government support under Specific Cooperative Agreement No. 58-5358-4542 awarded by the United States Department of Agriculture. The government has certain rights in the invention.
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| Number | Date | Country | |
|---|---|---|---|
| 20160205823 P1 | Jul 2016 | US |
