U.S. patent number PP30,788 [Application Number 15/932,716] was granted by the patent office on 2019-08-13 for triploid interspecific hybrid flowering pear tree named `ncpx2`.
This patent grant is currently assigned to NORTH CAROLINA STATE UNIVERSITY. The grantee listed for this patent is North Carolina State University. Invention is credited to Thomas G. Ranney.
United States Patent |
PP30,788 |
Ranney |
August 13, 2019 |
Triploid interspecific hybrid flowering pear tree named `NCPX2`
Abstract
`NCPX2` is a new triploid, interspecific hybrid flowering pear
with a broadly pyramidal habit, white flowers, multi-coloured fall
foliage, resistance to fire blight, and significantly reduced
fertility.
Inventors: |
Ranney; Thomas G. (Raleigh,
NC) |
Applicant: |
Name |
City |
State |
Country |
Type |
North Carolina State University |
Raleigh |
NC |
US |
|
|
Assignee: |
NORTH CAROLINA STATE UNIVERSITY
(Raleigh, NC)
|
Family
ID: |
67543483 |
Appl.
No.: |
15/932,716 |
Filed: |
April 11, 2018 |
Current U.S.
Class: |
PLT/177 |
Current CPC
Class: |
A01H
5/08 (20130101); A01H 6/7481 (20180501) |
Current International
Class: |
A01H
5/00 (20180101); A01H 6/74 (20180101) |
Field of
Search: |
;PLT/177 |
Other References
J Frank Schmidt & Song Co., Reference Guide, (p. 58; "Chastity
Pear.TM.") Jan. 2018, 2 pages. cited by applicant .
Phillips, Whitney D. et al. "Fertility and Reproductive Pathways of
Triploid Flowering Pears (Pyrus sp.)", HortScience, 51(8) 968-971
(2016). cited by applicant.
|
Primary Examiner: McCormick Ewoldt; Susan
Attorney, Agent or Firm: Myers Bigel, P.A.
Claims
What is claimed is:
1. A new and distinct triploid, interspecific hybrid flowering pear
tree named `NCPX2` as illustrated and described herein.
Description
Latin name of the genus and species: The Latin name of the novel
plant variety disclosed herein is Pyrus x triploida.
Variety denomination: The inventive triploid, interspecific hybrid
of Pyrus calleryana (tetraploid) x Pyrus `Silver Ball` (diploid
hybrid) disclosed herein has been given the varietal denomination
`NCPX2`.
BACKGROUND OF THE INVENTION
The present invention comprises a new and distinct hybrid flowering
pear cultivar hereinafter referred to by the cultivar name `NCPX2`.
This new flowering pear was developed through a breeding program in
Mills River, N.C. `NCPX2` was selected from an F.sub.1 population
of seedlings grown from a controlled cross of an induced tetraploid
Pyrus calleryana (H2002-031-010) (female parent; unpatented) x
Pyrus `Silver Ball` (diploid hybrid) (male parent; unpatented). The
first asexual propagation of `NCPX2` was carried out in August 2010
by budding in Mills River, N.C. and has been asexually reproduced
repeatedly by budding over a 5-year period. `NCPX2` propagates
readily from budding using chip budding in mid-summer. `NCPX2` has
been found to retain its distinctive characteristics through
successive asexual propagations.
SUMMARY OF THE INVENTION
The following are the unique and distinguishing characteristics of
this new cultivar when grown under standard horticultural practices
in Mills River, N.C. 1. Triploid selection with greatly reduced
fertility. 2. An upright, pyramidal form with white flowers. 3.
Resistance to fire blight. 4. Showy fall foliage color.
BRIEF DESCRIPTION OF THE PHOTOGRAPHS
This new flowering pear is illustrated by the accompanying
photographs which show the plant's form, foliage and
inflorescences. The colors shown are as true as can be reasonably
obtained by conventional photographic procedures. 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 pear.
FIG. 1 is a photograph demonstrating the upright pyramidal form of
an eight year old tree of `NCPX2`.
FIG. 2 is a photograph showing the white flowers from an eight year
old tree of `NCPX2`.
FIG. 3 is a photograph showing fall foliage colors of a nine year
old tree of `NCPX2`.
DETAILED BOTANICAL DESCRIPTION
The following is a detailed description of the botanical
characteristics of the new and distinct variety of interspecific
hybrid flowering pear known by the denomination `NCPX2`. The
detailed description was taken on the original nine-year-old tree
growing in Mills River, N.C. All colors cited herein refer to The
Royal Horticultural Society Colour Chart (The Royal Horticultural
Society (R.H.S.), London, 2015, 6th Edition). Where specific
dimensions, sizes, colors, and other characteristics are given, it
is to be understood that such characteristics are approximations or
averages set forth as accurately as practicable.
TECHNICAL DESCRIPTION OF THE VARIETY
Classification: Botanical name.--Pyrus x triploida `NCPX2`. Common
name.--Triploid hybrid flowering pear. Parentage: F.sub.1 hybrid of
Pyrus calleryana H2002-031-010 (tetraploid) x Pyrus `Silver Ball`
(diploid interspecific hybrid of uncertain parentage, possibly P.
fauriei x P. betulaefolia). Plant description: Growth
habit.--Upright pyramidal. Height: 8 m after 9 years. Width: 6 m
after 9 years. Shoots and stems.--Branching habit: Upright
spreading. Lateral branch length: 3 to 6 m. Diameter: 3 to 9 cm.
Internode length: 2 to 5 cm. Color: Brown (N200B). Trunk texture:
Smooth to rough. Trunk color: Brown (N200C to N200D). Mature
leaves.--Type: Simple. Persistence: Deciduous. Arrangement:
Alternate. Shape: Ovate. Apex: Acuminate. Base: Rounded. Venation:
Pinnate. Margin: Serrulate. Texture: Glabrous both upper and lower.
Emerging leaves.--Color: Upper surface: Yellow-Green (146A). Lower
surface: Yellow-Green (146B). Mature leaves during growing
season.--Color: Upper: Green (137A). Lower: Yellow-Green (146B).
Length of lamina: Avg. 6.1 cm (range 5.5 to 7.0 cm). Width: Avg.
4.6 cm (range 3.5 to 5.0 cm). Petiole: Length: Avg. 3.0 cm (range
2.5 to 4.0 cm). Width: 0.1 cm. Color: Yellow-Green (146D). Mature
leaves, fall color.--Variable. Including Brilliant Orange Yellow
(21B), Vivid Red (46C), and Deep Red (53A). Inflorescence.--Bud
length: 0.5-0.6 cm. Bud diameter: 0.8-1.0 cm. Bud shape: Ovate. Bud
color: Green-White (157C) with Red-Purple (63C) on tip. Individual
flowers.--Diameter: 1.5-2.0 cm. Depth: 0.6-0.8 cm. Stamen: Number:
19-22. Anther color: Red-Purple (63A). Filament color: Green-White
(157D). Pistil: Number: 2. Stigma: Shape: Rounded. Color:
Greyed-Green (193A). Style: Length: 0.5-0.6 cm. Color: Yellow-Green
(144D). Ovary color: Green (138A). Petals: Arrangement: Star.
Number: 5 petals. Shape: Elliptic. Margin: Entire. Tip: Obtuse.
Length (at anthesis): 0.8-1.0 cm. Width (at anthesis): 0.7-0.9 cm.
Color when opening: Green-White (157D). Color fully opened: White
(NN155C). Fruit.--Pome: 4 locules. Size: 0.5-1.0 in. diameter.
Shape: Round to ovoid. Color: Gray orange to gray brown (including
177B, N199B, N199D). Lenticels: Many small, circular on surface.
Calyx: Mostly deciduous. Length: 0.1-0.11 in. Diameter: 0.08-0.1
in. Pedicel: Length: 0.55-1 in. Diameter: 0.03-0.05 in. Color:
Green (132B). Disease and insect resistance: No significant disease
or insect pests have been observed. `NCPX2` was found to have a
high level of resistance to fire blight (see data below). Cold
hardiness: At least USDA zone 5b; testing has not been completed in
colder zones. Nomenclature: To help clarify the nomenclature of
Pyrus spp. hybrids, nothospecies Pyrus x triploida Ranney is
proposed for the hybrid species name in accordance with Article
H.3-5 (McNeill et al., 2012). The new hybrid species is described
as follows: Nothospecies Pyrus x triploida Ranney, a triploid,
interspecific hybrid between Pyrus calleryana Decne. and another
Pyrus L. species or hybrid. Primary diagnostic characteristics are
a 2C holoploid relative genome size of approximately 1.88.+-.0.12
(Standard Error) pg reflecting an intermediate triploid between
tetraploid 2.63.+-.0.06 (SE) pg and diploid 1.25.+-.0.05 (SE) pg
parents (Following methods of Phillips et al., 2016). Typification:
Pyrus x triploida Ranney, nothosp. nov. Type: United States, N.C.,
Mills River, 2C relative genome size of 1.93 pg, 8 m tall, 6 m
wide, upright pyramidal form, NCSU H2008-049-145, 11 Nov. 2017,
Ranney MCIL 2017-001 (holotype: NCSC, here designated; isotype
NA).
MOPHOLOGICAL COMPARISONS WITH OTHER TAXA
A comparison of morphological characteristics between `NCPX2` and
other commercial flowering pear cultivars is presented in Table
1.
TABLE-US-00001 TABLE 1 Morphological comparison of `NCPX2` with
other commercial flowering pear cultivars Cultivars Pyrus Pyrus
calleryana Pyrus `NCPX1` Pyrus `Cleveland pyrifolia (U.S. `Silver
Select` `Ohara Plant Ball` (unpat- Beni` Pat. No. Pyrus (unpat-
Trait ented) (unpatented) 26,539) `NCPX2` ented) Tree Upright
Upright Very Upright Compact, growth pyramidal columner. narrow
pyramidal round, Habit fastigate dwarf Tree 8 m 8 m 8 m 8 m 4 m
Height (after 8 years) Tree 6 m 5 m 2m 6 m 4 m Width (after 8
years) Flower White Red Red Green- Green- bud (N155A) purple purple
white White color (53C to (53C to (157C) (157B) 63A) 63A) with Red-
Purple (63C) on tip. Flower White White White Green- Green petal
(N155A) (N155A) (N155A) White white color with some with some
(157D) (157D) when pink blush pink blush opening (63A, (63A, 58C,
and 58C, and 65A) 65A) Flower White White White/ White White petal
(N155A), (N155A), pink (NN155C) (N155) color (155B) when fully
opened Flower 1.0 to 2.5 to 3.1 to 1.5-2.0 cm 1.0 to diameter 2.0
cm 3.3 cm 3.6 cm 2.5 cm
FIRE BLIGHT RESISTANCE
Disease resistance to fire blight was evaluated following the
procedures of Bell et al, (2004). Briefly, a virulent strain of
Erwinia amylovora (E2002a) was prepared from 24 hour old cultures
grown on nutrient agar. Three actively growing shoots were
inoculated in May 2012 by bisecting the youngest leaves with a pair
of scissors that had been dipped into the inoculum prior to each
cut. The disease lesion length and total length of the current
season's growth of the inoculated shoot were measured 40 days
following inoculation. The severity of infection was expressed as
the length of the fire blight lesion as a percentage of overall
shoot length. `NCPX2` was found to have a high level of resistance
to fire blight with a mean lesion length of 0.8% following
controlled inoculations (Table 2). No signs or symptoms of fire
blight have been observed on `NCPX2` as the result of natural
infection over the last 8 years.
TABLE-US-00002 TABLE 2 Comparison of tire blight resistance among
`NCPX2` and other commercial flowering pear Cultivars. Disease
severity - 2012 (% lesion length) Cultivar Range Mean. `Ohara Beni`
100-100 100 `Cleveland Select` 0-20 6.6 `NCPX1` 0-0 0.0 `NCPX2` 0-3
0.8
REPRODUCTIVE CHARACTERISTICS
Female fertility of selected triploid pears, including `NCPX2`
(H2008-049-145) was evaluated and published by Phillips et al.
(2016) with a summary presented in Table 3. Female fertility was
characterized by evaluating fruit set, seeds per fruit, seed
germination, seedlings per flower, and percent relative fertility
[(seedlings per flower for triploid/seedlings per flower for
diploid control).times.100], outdoors with favorable cross
pollination conditions. Flow cytometry was used to determine
relative genome sizes and ploidy levels. Relative fertility of
`NCPX2` was 0.86% of the most fertile diploid control, a reduction
of 99.14%. Furthermore, the limited seedlings that did germinate
from triploids maternal parents, including `NCPX2`, were determined
to be primarily abnormal aneuploids with non-standard chromosome
numbers.
TABLE-US-00003 TABLE 3 Ploidy, relative 2C genome size, and
fertility characteristics for `NCPX2` and selected diploids as
published by Phillips et al. (2016). Rela- tive Re- gen- Ger-
lative ome Fruit min- Seed- fertil- Ploidy size set Seeds/ ation
lings/ ity.sup.Z Selection (X) (pg) (%) fruit (%) flower (%)
`NCPX2` 3 1.93 .+-. 3.46 .+-. 2.05 .+-. 5.22 .+-. 0.01 .+-. 0.86
(H2008- 0.01 0.07 3.48 0.11 0.01 049-145) Diploid 1 2 1.26 .+-.
9.80 3.89 .+-. 38.61 0.13 .+-. 16.73 0.02 .+-. 2.93 .+-. 0.08 0.07
0.11 Diploid 2 2 1.22 .+-. 11.06 3.24 .+-. 25.45 0.13 .+-. 16.3
0.01 .+-. 0.51 .+-. 0.35 0.11 0.49 Diploid 3 2 1.23 .+-. 46.76 3.16
.+-. 52.83 0.80 .+-. 100.00 0.01 .+-. 0.72 .+-. 0.62 0.22 0.15
.sup.ZCalculated as (seedlings/flower)/(0.80), where 0.80 is the
number of seedlings per flower of the most fertile diploid
eontrol,
`NCPX2` is distinguished from other flowering pear cultivars by its
unique combination of traits including a triploid cytotype with a
2C genome size of approximately 1.93 pg, an upright pyramidal form,
white flower petals, high resistance to fire blight, and low female
fertility.
CITATIONS
Bell, A. C., T. G. Ranney, and T. A. Eaker. 2004. Resistance to
fire blight among flowering pears and quince. HortScience
40(2):413-415. McNeill, J., F. R. Barrie, W. R. Buck, V. Demoulin,
W. Greuter, D. L. Hawksworth, P. S. Herendeen, S. Knapp, K.
Marhold, J. Prado, W. F. Rrud'homme Van Reine, G. F. Smith, J. H.
Wiersema, and N. J. Turland. 2012. International code of botanical
nomenclature for algae, fungi, and plants (Melbourne Code). Koltz
Sci. Books, Oberreifenberg, Germany. Phillips, W. D., T. G. Ranney,
D. H. Touchell, and T. A. Eaker. 2016. Fertility and reproductive
pathways of triploid flowering pears (Pyrus sp.). HortScience
51(8):968-971.
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