These pears are challenging to find now. Here is what they say
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14 Sep 2022 Wade Mitchell
We had these pear trees where I grew up in SE Texas.(Zone 9a) The flesh is very hard but sugary sweet with a tough but thin skin. The core and seeds are small; most of the pear is edible meat. I enjoy them fresh, but they may be too hard for some folks’ liking. They’re great for canning and preserving as well as for baking. Like a Granny Smith apple, they hold their shape very well if baked into a pie. With four trees on a couple of acres, we usually had an abundance of them. After eating all we could, canning, and giving them away to friends, we always wound up feeding excess to our horses. They loved them as much as we did.
17 Apr 2018 Jeff SnyderMICHIGAN, United States
We’ve enjoyed these pears for decades from one tree in our farm orchard. Did not know its name until now, but there’s no mistaking it. Hard & sugar sweet with a nice aroma. Excellent keeper as well.
"
The rootstock fruit of old home x bartlett isn’t very different
Farmingdale pears are elongated with a swelling at the stem end.
Frank Reimer, pomologist at Oregon State University, first encountered Old Home and Farmingdale in an orchard in Illinois during his extensive search for pear germplasm with resistance to fireblight.
Old Home x Farmingdale pear rootstocks, which have been widely used by the U.S. pear industry for many years, should actually be called Old Home x Bartlett, it turns out.
Genetic fingerprinting done at the U.S. Department of Agriculture’s National Clonal Germplasm Repository in Corvallis, Oregon, revealed that it is impossible for Farmingdale to be the pollen parent of any of the several OHxF rootstocks tested.
This prompted Joseph Postman, curator of the repository, to retrace the story behind the OHxF rootstocks. It begins a century ago when Oregon State University pomologist Frank Reimer began scouring the world for pear germplasm with resistance to fireblight, a disease that had made its first appearance in Oregon’s Rogue River Valley in 1906. Reimer was the first superintendent of the OSU Southern Oregon Experiment Station near Medford.
Two of his most important discoveries came from a 1915 visit with fruit grower Benjamin Buckman in Farmingdale, Illinois. One was the cultivar Farmingdale, an open-pollinated seedling that Buckman had found near a d’Anjou pear tree on his farm. The other was Old Home, a seedling that had come from a nursery in Illinois some years earlier. Both these trees were completely free of fireblight. Reimer took scion wood of Old Home back to the Southern Oregon Experiment Station and had Farmingdale scions sent to him several years later.
After more than a decade of testing the many pear species in OSU’s collection, Reimer found only three European cultivarsFarmingdale, Longworth, and Old Homethat had excellent blight resistance when used as trunk stocks.
After Buckman died, the original Farmingdale and Old Home trees in Illinois were destroyed, and the trees at OSU became the primary source of nursery stock.
Fireblight resistant
Reimer found in the 1930s that when Farmingdale was used as a pollen parent in crosses with other blight-resistant selections, a high percentage of the resulting seedlings were highly resistant to fireblight, especially when the seed parent was Old Home.
Although crosses between other blight-resistant parents also produced seedlings that were resistant to blight, many of those seedlings became infected when a susceptible cultivar such as Bartlett or Bosc was grafted onto them. In those cases, fireblight could spread from an infected cultivar across the graft union into the rootstock. In contrast, the OHxF seedlings were resistant even to the spread of fireblight from a grafted cultivar.
One of Reimer’s goals was to establish a mother block of Old Home and Farmingdale trees in Medford to generate seed for producing blight-resistant seedling rootstocks. However, Lyle Brooks, owner of Daybreak Nursery in Forest Grove, Oregon, became concerned about the variability of pear cultivars grafted onto OHxF seedling rootstocks. Collaborating with Dr. Mel Westwood at OSU, Corvallis, he set out to develop clonal rootstocks from those two parents.
In 1950, he obtained half a kilogram of seeds from what he described as an isolated block of Old Home trees planted with Farmingdale pollinizers at the Canadian Department of Agriculture Research Unit near Summerland, British Columbia. It now appears that Bartlett must have been planted in the vicinity of the Summerland pear block where Brooks obtained the seeds.
Patented
Of the 2,000 seedlings he grew from those seeds, 516 were planted in a nursery block for evaluation. Thirteen of the more easily propagated selections were evaluated in trials for disease resistance and many other traits, including hardiness, precocity, compatibility with pear varieties, and tolerance to pear decline, as well as resistance to fireblight.
Several, including OHxF 69, 87, 97, and 333, were patented in 1988 by Carlton Nursery, which was operated by the Brooks family. The rootstocks have been propagated worldwide and continue to be in high demand, though some lack the size control and precocity needed for high-density orchards.
More than 40 of the OHxF selections are preserved at the National Clonal Germplasm Repository. In 2009, Postman and ARS plant geneticist Dr. Nahla Bassil did genetic fingerprinting of pears in the collection and found that d’Anjou was very likely the maternal parent of Farmingdale, as Buckman and Reimer had suspected.
They then went on to do genetic paternity testing of six OHxF selections (51, 69, 87, 97, 230, and 333), along with a number of other cultivars. All the OHxF selections proved to be related to Old Home, but the tests showed that Farmingdale was highly unlikely to be a pollen parent. On the other hand, there was a strong indication that Bartlett was genetically related to all those selections.
Puzzle
Postman said this explained what had been something of a puzzle to him over the years: While fruit of the OHxF selections in the germplasm collection resembles Old Home, which has a distinctive round shape, it does not at all resemble Farmingdale. The shape of OHxF fruit tends to be intermediate between that of Old Home and Bartlett. Similarly, the foliage of the OHxF selections resembles the foliage of Old Home but not Farmingdale.
Lynnell Brandt, president of Brandt’s Fruit Trees in Yakima, Washington, said his father Everette worked at Carlton Nursery during the time when Brooks was testing the OHxF rootstocks to identify the most promising ones. Lynnell, who joined the staff of Carlton Nursery in the late 1970s, said he felt confident that both Brooks and Westwood believed that Farmingdale was the pollinizing parent.
“Who were we to question those two?” he asked. “They were the world’s leaders in pear understocks. And it seems strange to me, because Lyle would definitely notice the difference between Bartlett and Farmingdale. He would have known the leaves were different.”
Postman said the fact that the OHxF rootstocks have no Farmingdale heritage means that the highly fireblight-resistant Farmingdale is under-represented in the pedigrees of the pear rootstocks currently used in the pear industry as well as in the parent material being used in rootstock breeding programs.
Although Farmingdale is not likely to instill either dwarfing or precocity in its offspring, Farmingdale germplasm should be reconsidered if fireblight resistance is to be an important genetic trait in future pear cultivars and rootstocks, he suggests.
Future DNA fingerprinting in the USDA pear gene bank should help breeders better understand the paternity of parents when making crosses to develop improved varieties, he added.
The question now is whether the OHxF rootstocks should be renamed. The patent expired in 2005, so no one owns the OHxF name.
“Water’s gone under the bridge for so long, so whether they’re Bartlett or Farmingdale, everyone will probably continue to call them OHxF so things don’t get confused,” said Joe Dixon, sales representative with Carlton Plants. “There’s really nobody who would rename them or have the rights to do so, I don’t think.” •"
Growing the farmingdale for many years now. It is fireblight free Farmingdale pear for seedling rootstocks! . If we look at ohxf rootstocks they are actually old home x bartlett. They are very closely related to harrow delight and harrow sweet in that 2 of the 3 pears used are the same types. Early sweet pear is the only difference. Purdue 80-51 is more or less the same as a rootstock. Everyone knows i talk a lot about rootstock Pear rootstocks influence on Fruit size
" Early in the 20th century, a collection of fire blight resistant pears from around the world was assembled in southern Oregon in efforts to develop improved rootstocks. ‘Old Home’ and ‘Farmingdale’ are two cultivars from Illinois that exhibited fire blight resistance and useful horticultural traits. Both became important as interstem stocks and as parents in the development of new rootstocks. In the 1950s, an Oregon nurseryman collected seed from an ‘Old Home’ tree in British Columbia pollinated by ‘Farmingdale’ and hundreds of numbered selections of this cross ‘Old Home’ x ‘Farmingdale’ (OHxF) were evaluated. Several OHxF selections are now used as rootstocks worldwide, and 45 unique OHxF selections are maintained at the USDA-ARS National Clonal Germplasm Repository (NCGR), in Corvallis, Oregon. Simple Sequence Repeat (SSR) or microsatellite-based profiles were generated for ‘Old Home’, ‘Farmingdale’, 8 OHxF selections, and standard pear cultivars at NCGR using a standard fingerprinting set developed by the European Cooperative Programme for Plant Genetic Resources. ‘Farmingdale’ is thought to be a seedling of ‘Beurr d’Anjou’, and shared at least one SSR allele at each locus tested, confirming this parental relationship. All OHxF selections shared an allele with ‘Old Home’ at each locus, with one allele carrying a suspected pair of base deletions. However, based on the SSR results, it is impossible for ‘Farmingdale’ to be the pollen parent for any of the OHxF selections examined. Evaluation of the world pear collection at NCGR with this fingerprinting set will help identify the actual pollen parent of these rootstocks.
Journal of the American Pomological Society 67(3): 157-167 2013
OH˟ F Paternity Perplexes Pear Producers
JosEpH postMan1, daEil kiM2, and naHla bassil1
1 USDA Agricultural Research Service, National Clonal Germplasm Repository, Corvallis, Oregon, USA.
2 Department of Horticultural Science, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
Abstract
Early in the 20th century, a collection of re blight resistant pears from around the world was assembled in
southern Oregon in an effort to develop improved rootstocks. ‘Old Home’ and ‘Farmingdale’ are two cultivars
from Illinois that exhibited strong re blight resistance and useful horticultural traits. Both became important as
interstem stocks and as parents in the development of new rootstocks. In the 1950s, an Oregon nurseryman col-
lected seed from an ‘Old Home’ tree in British Columbia purportedly pollinated by ‘Farmingdale’ and hundreds
of numbered selections of this cross of ‘Old Home’ × ‘Farmingdale’ (OH×F) were evaluated. Several OH×F
selections are now valued as rootstocks worldwide, and 45 unique OH×F selections are maintained at the USDA-
ARS National Clonal Germplasm Repository (NCGR), in Corvallis, Oregon. Simple Sequence Repeat (SSR)
or microsatellite-based proles were generated for ‘Old Home’, ‘Farmingdale’, 8 OH×F selections, and several
reference pear cultivars at NCGR using a standard ngerprinting set developed by the European Cooperative
Programme for Plant Genetic Resources. ‘Farmingdale’ is thought to be a seedling of ‘Beurré d’Anjou’. Our
study showed that ‘Farmingdale’ shared at least one SSR allele with ‘Anjou’ at each locus tested, conrming this
parental relationship. Our studies showed that all OH×F selections shared an allele with ‘Old Home’ at each locus,
with one allele carrying a suspected pair of base deletions. However, based on our SSR results, it is impossible for
‘Farmingdale’ to be the pollen parent for any of the OH×F selections examined. Evaluation of the world pear col-
lection at NCGR with this ngerprinting set established the cultivar ‘Bartlett’ as the actual pollen parent of these
rootstock clones. Fruit and leaf morphology is also consistent with ‘Bartlett’ and not ‘Farmingdale’ as a parent of
OH×F rootstock selections. The highly re blight resistant ‘Farmingdale’ is apparently very under-represented in
the pedigrees of current pear rootstocks, and deserves renewed consideration.
Early in the 20th century, Oregon State Uni-
versity (OSU) professor Frank Reimer began
scouring the world for Pyrus germplasm with
resistance to the important bacterial disease
re blight (Erwinia amylovora (Burrill) Win-
slow et al.), which made its rst appearance
in the Rogue River Valley in 1906 (Reimer,
1925). Reimer was the rst superintendent
of the OSU Southern Oregon Experiment
Station near Medford. From 1917 to 1919
his travels took him to China, Korea, Man-
churia, and Japan where he collected scions
from many local pear cultivars and seed from
pear wild relative species (Reimer, 1919;
Fig. 1). He also collected seed from wild and
hedgerow perry pears in France, and clones
of hundreds of the leading pear cultivars of
Western Europe and North America. Seed-
ling populations were generated and clones
were grafted and established at the OSU
station in Talent, Oregon, where the diverse
germplasm collections were evaluated for
fruit quality, disease resistance and as poten-
tial rootstocks (Reimer, 1919; Reimer, 1925;
Fig. 1. Frank C. Reimer traveling while investigating
pears in northern China in 1919.
158 Journal of the american Pomological Society
Hartmann, 1957). Two of Professor Reimer’s
most valuable discoveries came from a 1915
trip to visit fruit grower Benjamin Buck-
man in Farmingdale, Illinois. One was the
cultivar ‘Farmingdale’, an open pollinated
seedling Buckman had found near a ‘Beur-
ré d’Anjou’ tree on his farm, and the other
was ‘Old Home’, a seedling that had come
from a nursery in Paris, Illinois some years
earlier. Reimer observed both of these trees
to be completely free of re blight and he
brought scions from ‘Old Home’ back to Or-
egon when he returned. ‘Farmingdale’ scions
were sent to him several years later (Hum-
mer, 1998; Westwood and Brooks, 1963;
Westwood, 1967). After more than a decade
of observing natural infections, and perform-
ing articial inoculations in southern Oregon
with E. amylovora, Reimer found many pear
species selections and Asian cultivars with
strong re blight resistance, but only three
European cultivars: ‘Farmingdale’, ‘Long-
worth’, and ‘Old Home’ had excellent blight
resistance as trunk stocks (Reimer, 1925).
The many valuable pear selections identied
or developed by Reimer and his successors
were later transferred to the National Clonal
Germplasm Repository at Corvallis, Oregon
when the USDA Agricultural Research Ser-
vice established this genebank in 1981 (Post-
man et al., 2006; Westwood, 1982).
‘Farmingdale’. The origin and character-
istics of ‘Farmingdale’ are discussed in con-
siderable detail by Reimer (Reimer, 1925;
Reimer, 1950). It is apparently a pure form
of P. communis which originated as a chance
seedling in the orchard of Benjamin Buck-
man, at Farmingdale, Illinois. The fruit size
is medium to large, and it resembles ‘Anjou’
in form and coloration. Flesh is white, fairly
ne, buttery, moderately juicy, and quite free
of grit. It is reasonably sweet but somewhat
lacking in desirable avor characteristics,
and ripens in midseason. The original seed-
ling was discovered close to an ‘Anjou’ tree,
which was presumed to be the parent. Hart-
mann (1957) noted “while this pear is of little
value for its fruit, it is quite remarkable in
other characteristics. Its tree is vigorous, well
formed, fairly productive, and is the most
blight resistant of all the P. communis cul-
tivars tested at the Southern Oregon Branch
Experiment Station.”
‘Old Home’. ‘Old Home’ is also appar-
ently a pure form of P. communis that origi-
nated as a chance seedling with B.O. Curtiss,
at Paris, Illinois (Hartmann, 1957) and was
growing in Benjamin Buckman’s trial or-
chard in Farmingdale prior to 1907 (Ragan,
1908). The fruit of ‘Old Home’ is small,
round, slightly truncate, with no neck. Skin
is yellow-green, becoming yellow when
ripe. Flesh is white to yellow, ne textured,
becoming soft and tender when ripe with
few stone cells, medium dry, subacid and
with poor avor (Howlett, 1957). While its
fruit is of no consequence, the variety was
widely used as a blight resistant trunk and
framework stock, and as a very good source
of blight resistant seedlings. When crossed
with ‘Farmingdale’, a high percentage of the
seedlings were very blight resistant as well
as vigorous and uniform in growth (Hart-
mann, 1957). Reimer (1925) found ‘Old
Home’ to have very good graft compatibility
with quince and it has since been used as an
interstem bridge for incompatible pear cul-
tivars. Westwood (1967) showed that ‘Old
Home’ is also graft compatible on hawthorn
(Crataegus sp.) rootstock. When the disease
Pear Decline spread through the pear grow-
ing areas of British Columbia in the 1940s
and through Washington, Oregon and Cali-
fornia in the 1950s and 1960s, it was found
that trees with ‘Old Home’ root or trunk
stocks were much more resistant to pear de-
cline as well as to re blight. ‘Old Home’ was
extremely difcult to propagate as a clonal
rootstock, however, while many OH×F se-
lections rooted much easier from hardwood
cuttings (Westwood and Brooks, 1963).
‘Old Home’ and ‘Farmingdale’ in breed-
ing. In the mid 1920s, following the death of
Benjamin Buckman, the original ‘Farming-
dale’ and ‘Old Home’ trees in Illinois were
destroyed, and the trees established at South-
159
ern Oregon Experiment Station became the
primary source of nursery stock (Fig. 2;
Brooks, 1984; Hummer, 1998; Westwood,
1967). Reimer (1950) found in the 1930s that
when ‘Farmingdale’ was used as a pollen
parent in crosses with other blight resistant
selections, a high percentage of the resulting
seedlings exhibited a high resistance to blight.
This was especially true when ‘Old Home’
was the seed parent. Although a number of
crosses between other blight resistant parents
resulted in >90% seedlings that were resis-
tant to blight following inoculation, many
of those resistant seedlings became infected
when a susceptible cultivar such as ‘Bartlett’
or ‘Beurré Bosc’ was grafted onto them. In
those cases, re blight could spread from an
infected cultivar across the graft union into
the rootstock. However, the OH×F seedlings
were resistant even to the spread of re blight
from infection of a grafted cultivar (Reimer,
1950). Based on Reimer’s work, ‘Old Home’
and ‘Farmingdale’ became important parent
pEar
Fig. 2. HortScience cover in 1967 showing F. Reimer
by original Old Home tree recently transplanted to Tal-
ent, Oregon.
stocks for the development of both rootstock
and edible pear cultivars. Several important
Canadian cultivars obtained their re blight
resistance from ‘Old Home’, and at least two
US fruit cultivars have ‘Farmingdale’ in their
pedigrees (Table 1). By far, the most im-
portant use of ‘Farmingdale’ and especially
‘Old Home’ has been in the development of
pear rootstocks. ‘Old Home’ in particular has
been a valuable parent in rootstock breeding
programs in France, UK, Germany, and else-
where (Table 1; Elkins et al., 2012).
OH×F selections. One of Reimer’s goals
was to establish a mother block of ‘Old
Home’ and ‘Farmingdale’ at the Southern
Oregon Experiment Station to generate seed
for producing blight resistant seedling root-
stocks. Oregon nurseryman Lyle Brooks was
concerned about the variability of pear culti-
vars grafted onto OH×F seedling rootstocks,
and he set out to develop clonal rootstocks
from this cross. In 1952, he obtained half a
kilogram of seed from an isolated block of
‘Old Home’ trees planted with ‘Farmingdale’
pollenizers at the Canada Research Station in
Summerland, British Columbia. Of the thou-
sands of resulting seedlings, he planted 516
in a nursery block and evaluated them for
ease of propagation from cuttings and other
traits (Brooks, 1984; Westwood and Brooks,
1963). Propagation by hardwood cuttings
was successful, and thirteen of the more eas-
ily propagated OH×F numbered selections
(OH×F 18, 34, 51, 69, 87, 97, 112, 198, 217,
230, 267, 333, and 361) were extensively
evaluated at OSU for disease and insect re-
sistance, environmental tolerance, anchor-
age, dwarng and fruit production of grafted
cultivars (Lombard and Westwood,1987).
More than 40 OH×F selections, including the
13 above, are preserved at the USDA gene-
bank in Corvallis (Table 2). Some continue
to be propagated worldwide and are in high
demand for new plantings even though they
lack the size control and precocity demanded
for high density orchards (Elkins et al., 2012).
OH×F 333 was selected for its resistance to
multiple diseases and moderate size control
160 Journal of the american Pomological Society
to be the standard clonal rootstock for the
thousands of pear clones maintained at the
USDA genebank (Postman, 2008a; 2008b).
A new generation of seedlings generated
from open pollinated (OP) seed collected
from an isolated group of select OH×F clones
(OH×F 40, 51, 87, 333 and 339) resulted in
the Horner rootstock series (Table 2; Mielke
and Smith, 2002; Mielke and Sugar, 2004).
Horner 4 is under evaluation in the 2005 NC-
140 collaborative pear rootstock trial (Elkins
et al., 2011), and a trial comparing Horner 4,
Horner 10 and OH×F 87 was established in
2009 in the states of Oregon and Washington
(Einhorn, personal communication).
DNA ngerprints. Bassil and Postman
(2009) developed expressed sequence tag
(EST)-simple sequence repeat (SSR) mark-
ers and evaluated them for usefulness in a
diverse collection of individuals from the
three most commonly cultivated pear spe-
cies: P. communis, P. pyrifolia and P. ussu-
riensis at the USDA genebank. They found
that ‘Farmingdale’ shared one SSR allele
with ‘Anjou’ at each of 10 loci, suggesting
that ‘Anjou’ was very likely the maternal par-
ent of ‘Farmingdale’, as Buckman and Re-
imer had suspected nearly a century earlier
(Bassil and Postman, 2009; Hartmann, 1957;
Reimer, 1925). OH×F 333 was the only se-
lection included in that study and appeared
to share one allele with either ‘Old Home’ or
‘Farmingdale’, thus conrming its reported
parentage. This paper reports on the pheno-
Table 1. Pear selections reported to have either ‘Old Home’ or ‘Farmingdale’ in the pedigree, and USDA gene-
bank accession numbers.
Plant name Pedigree Accession no. Origin
Farmingdale in Pedigree
P. betulifolia-2 x Farmingdale P. betulifolia-2 x Farmingdale PI 541785 United States
Rogue Red Comice x (Seckel x Farmingdale sdlg. 122) PI 541252 United States
Vistica Nectar Farmingdale x Burkett none United States
Old Home in Pedigree
AC Harrow Gold (HW 616) Harvest Queen x Harrow Delight none Canada
BU 2/33 (Pyro II) Old Home x Bonne Louise d’Avranches PI 617679 Germany
Harrow Delight (HW 603) Bartlett x (Early Sweet x Old Home) PI 541431 Canada
Harrow Sweet (HW 609) Bartlett x (Old Home x Early Sweet) PI 617562 Canada
Harrow Sweet (Old Home x Early Sweet) x HW
Harrow selection HW 623 605 none Canada
Harrow selection HW 624 Harrow Sweet x NY10353 none Canada
Nijisseiki x Old Home Nijisseiki x Old Home PI 541767 United States
OH 11 (Pyriam) Seedling of Old Home CPYR 2700 France
OH 20 re blight resistant Old Home seedling selection PI 541237 United States
rootstock
OH 50 re blight resistant Old Home seedling selection PI 541238 United States
rootstock
Old Home x P. betulifolia-1 Old Home x P. betulifolia-1 PI 541787 United States
Old Home x P. betulifolia-1 Old Home x P. betulifolia-1 PI 541788 United States
Pyrodwarf Old Home x Bonne Louise d’ Avranches PI 617654 Germany
QR 708-02 BP-1 x Old Home PI 617680 United Kingdom
QR 708-12 BP-1 x Old Home CPYR 2704 United Kingdom
QR 708-36 BP-1 x Old Home CPYR 2705 United Kingdom
Nijisseiki x Old Home (seedlot) Nijisseiki x Old Home W-6 PI 541753 United States
Old Home x Bartlett (seedlot) Old Home x Bartlett PI 541380 United States
161
pEar
Table 2. Pear selections reported to have both ‘Old Home’ and ‘Farmingdale’ in pedigree, and USDA genebank ac-
cession numbers.
Plant name Pedigree Accession no. Origin
Harrow selection (Anjou x Farmingdale) x Harrow Delight none Canada
HW 621
Horner 4 O.P. from population of OHxF 40, 51, 87, 333 & 339 CPYR 2955 United States
Horner 10 O.P. from population of OHxF 40, 51, 87, 333 & 339 CPYR 2956 United States
Horner 51 O.P. from population of OHxF 40, 51, 87, 333 & 339 PI 657931 United States
OHxF 1 Old Home x Farmingdale seedling selection PI 541408 United States
OHxF 2 Old Home x Farmingdale seedling selection PI 541413 United States
OHxF 4 Old Home x Farmingdale seedling selection PI 541409 United States
OHxF 5 Old Home x Farmingdale seedling selection PI 541410 United States
OHxF 7 Old Home x Farmingdale seedling selection PI 541399 United States
OHxF 9 Old Home x Farmingdale seedling selection PI 541421 United States
OHxF 18 Old Home x Farmingdale seedling selection PI 541397 United States
OHxF 23 Old Home x Farmingdale seedling selection PI 541411 United States
OHxF 29 Old Home x Farmingdale seedling selection PI 541398 United States
OHxF 34 Old Home x Farmingdale seedling selection PI 541412 United States
OHxF 40 Old Home x Farmingdale seedling selection PI 541402 United States
OHxF 51 Old Home x Farmingdale seedling selection PI 541369 United States
OHxF 58 Old Home x Farmingdale seedling selection PI 541454 United States
OHxF 69 Old Home x Farmingdale seedling selection PI 665738 United States
OHxF 87 Old Home x Farmingdale seedling selection PI 541415 United States
OHxF 97 Old Home x Farmingdale seedling selection PI 541370 United States
OHxF 101 Old Home x Farmingdale seedling selection PI 541416 United States
OHxF 109 Old Home x Farmingdale seedling selection PI 541417 United States
OHxF 112 Old Home x Farmingdale seedling selection PI 541418 United States
OHxF 130 Old Home x Farmingdale seedling selection PI 541406 United States
OHxF 132 Old Home x Farmingdale seedling selection PI 541404 United States
OHxF 198 Old Home x Farmingdale seedling selection PI 541419 United States
OHxF 217 Old Home x Farmingdale seedling selection PI 541371 United States
OHxF 226 Old Home x Farmingdale seedling selection PI 541372 United States
OHxF 230 Old Home x Farmingdale seedling selection PI 541420 United States
OHxF 247 Old Home x Farmingdale seedling selection PI 541422 United States
OHxF 257 Old Home x Farmingdale seedling selection PI 541396 United States
OHxF 259 Old Home x Farmingdale seedling selection PI 541423 United States
OHxF 261 Old Home x Farmingdale seedling selection PI 541401 United States
OHxF 266 Old Home x Farmingdale seedling selection PI 541424 United States
OHxF 267 Old Home x Farmingdale seedling selection PI 541400 United States
OHxF 280 Old Home x Farmingdale seedling selection PI 541425 United States
OHxF 282 Old Home x Farmingdale seedling selection PI 541426 United States
OHxF 288 Old Home x Farmingdale seedling selection PI 541373 United States
OHxF 319 Old Home x Farmingdale seedling selection PI 541427 United States
OHxF 333 Old Home x Farmingdale seedling selection PI 541405 United States
OHxF 340 Old Home x Farmingdale seedling selection PI 541403 United States
OHxF 361 Old Home x Farmingdale seedling selection PI 541374 United States
OHxF 377 Old Home x Farmingdale seedling selection PI 541428 United States
OHxF 501 Old Home x Farmingdale seedling selection PI 541407 United States
OHxF 512 Old Home x Farmingdale seedling selection PI 541414 United States
OPR-005 OHxF C-44 Bartlett x (Old Home x Farmingdale) PI 617519 United States
OPR-013 OHxF C-34 Old Home x Farmingdale PI 541368 United States
162 Journal of the american Pomological Society
typic verication of the ‘Farmingdale’ and
‘Old Home’ clones growing at the USDA
genebank, and the expanded SSR ngerprint-
ing of these cultivars and several OH×F root-
stock selections using a universal ngerprint-
ing set previously described by Evans et al.
(2009) that is made up of more polymorphic
genomic SSR loci.
Materials and Methods
Plant material. Young, actively growing
leaves were collected in the spring of 2007
from the clonal genebank accessions of ‘An-
jou’, ‘Old Home’, ‘Farmingdale’, OH×F 51,
OH×F 69 (3 sources), OH×F 87, OH×F 97,
OH×F 230, OH×F 333 and several standard
cultivars in the NCGR orchard collection in
Corvallis, Oregon (44.554° lat., -123.222°
long.). The OH×F 69 clone in the gene-
bank collection had come from OSU with a
note in its inventory record about a possible
identity question. In 2008, additional clones
of OH×F 69 that trace back to the original
Daybreak Nursery tree were obtained from
Fowler Nurseries (Newcastle, CA) and North
American Plants (McMinnville, Oregon) for
comparison.
DNA extraction. Thirty to 50 mg of leaf
tissue was placed in a cluster tube (Corn-
ing, Tewksbury, MA) containing a 4 mm
stainless steel bead (McGuire Bearing Com-
pany, Salem, OR). The samples were frozen
in liquid nitrogen and stored at -80°C, until
extraction. Grinding was performed in the
Retsch MM301 Mixer Mill, (Retsch, Inc.,
Hann, Germany) rapidly at a frequency of 30
cycles·s-1 using three 30 s bursts. DNA was
extracted with the Qiagen protocol described
in detail by Gilmore et al. (2011).
SSR genotyping. Twelve microsatellite
primers that make up a standard primer set
proposed by the European Cooperative Pro-
gram for Plant Genetic Resources (ECPGR)
(Evans et al., 2009) were used. A standard
set of six reference cultivars (Table 3) was
included to allow harmonization of genetic
data when comparing results generated in
different laboratories and using different sep-
aration platforms. The Type-it Microsatellite
Multiplex PCR Kit (Qiagen Inc., Valencia,
CA) was used to amplify SSRs in two reac-
tions of 15 µL total volume. The 15 µL PCR
reaction mix contained: 8.3 µL of 2x Type-it
Multiplex PCR Master Mix (Qiagen), 1.7 µL
of a 10x multiplex primer mix containing 2
µM of each primer, 1.7 µL Q solution, and
3.3 µL of 3ng·µL-1 template DNA. Touch-
down amplication was performed with a
Tetrad thermocycler (MJ Research, Inc., Wa-
tertown, MA) using an initial step of 95oC for
5 min, followed by 10 cycles of 95oC for 30
s, annealing temperatures starting at 62oC for
90 s (decreasing by 1oC/cycle), and 72oC for
30 s for extension. This step was followed
by 28 cycles of 95oC for 30 s, 52oC for 90 s,
and 72oC for 30 s, with a nal extension step
of 60oC for 30 min. Success of the PCR was
conrmed by 2% agarose gel electrophore-
sis. Fragment analysis followed separation
on a Beckman CEQ 8000 capillary genetic
analyzer (Beckman Coulter, Fullerton, CA).
Allele sizing and visualization were per-
formed using the fragment analysis module
of the CEQ 8000 software. Alleles were
scored by tting the peaks into bins less than
one nucleotide. For unweighted pair group
method with arithmetic mean (UPGMA)
cluster analysis, individuals were scored for
the presence or absence of each allele and
PowerMarker (Liu and Muse, 2005) was
used for cluster analysis.
Paternity testing. Paternity analysis for the
six OH×F selections included in this study
(Table 3) was carried out using a likelihood
approach with the CERVUS 3.0 software
(Kalinowski et al., 2007). Using the geno-
type le at the 12 loci, CERVUS was used
to determine allele frequency, to simulate pa-
ternity analysis and calculate critical values
of likelihood ratios. The paternity analysis
module (unknown sexes) used the twelve
cultivars included in the study as candidate
parents. Other parameters set for CERVUS
were 0.99 for the proportion of loci typed and
0.022 for rate of genotyping error.
Phenotype verication. Fresh fruits and
163
pEar
Table 3. Genotypic information at 12 SSR loci for ‘Old Home’, ‘Farmingdale’, 6 OH×F selections, and 10 pear cultivars available at USDA-ARS, NCGR. Alleles
present in Farmingdale but not observed in any of the OHxF selections are highlighted. Allele mismatches are underlined.
