U.S. patent number PP21,053 [Application Number 12/081,071] was granted by the patent office on 2010-06-08 for mint plant named `metolius`.
This patent grant is currently assigned to A. M. Todd. Invention is credited to Deven Holmgren, Jie Liu, Mark Morris.
United States Patent |
PP21,053 |
Liu , et al. |
June 8, 2010 |
Mint plant named `Metolius`
Abstract
A new and distinct variety of Mentha canadensis (`Metolius`) is
characterized by its unique oil chemistry and flavor profile
resembling that of peppermint oil, and by its tolerance to
Verticillium wilt (Verticillium dahliae) and mint rust (Puccinia
menthae). DNA microsatellite marker analysis has shown that
`Metolius` is a distinct variety of M. canadensis.
Inventors: |
Liu; Jie (Eugene, OR),
Holmgren; Deven (Eugene, OR), Morris; Mark (Eugene,
OR) |
Assignee: |
A. M. Todd (Eugene,
OR)
|
Family
ID: |
41165112 |
Appl.
No.: |
12/081,071 |
Filed: |
April 10, 2008 |
Prior Publication Data
|
|
|
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Document
Identifier |
Publication Date |
|
US 20090260119 P1 |
Oct 15, 2009 |
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Current U.S.
Class: |
PLT/259 |
Current CPC
Class: |
A01H
5/12 (20130101) |
Current International
Class: |
A01H
5/00 (20060101) |
Field of
Search: |
;PLT/259 |
Primary Examiner: McCormick Ewoldt; Susan B
Attorney, Agent or Firm: Baltatzis; Andreas Kramer &
Amado, P.C.
Claims
What is claimed is:
1. A new and distinct Mentha canadensis plant named `Metolius`
substantially as herein described and illustrated.
Description
Latin name of the genus and species of the plant claimed: Mentha
canadensis.
Variety determination: `Metolius`.
FIELD OF THE INVENTION
The present invention relates to a new and distinct mint
botanically known as Mentha canadensis. The new variety has been
named `Metolius` and will be referred as such hereafter.
BACKGROUND OF THE INVENTION
The present invention is a new variety of the mint species Mentha
canadensis (common name American cornmint/Japanese peppermint). The
essential oil industry refers to some members of the Mentha
canadensis species as "Mentha arvensis." This includes such popular
varieties as `Shivalik,` `Kosi,` and `Kalka.` Botanically, however,
these plants are M. canadensis species, with Mentha arvensis being
a different and significantly less commercial mint species commonly
referred to as a cornmint. The botanical differences allow one to
differentiate between the two species through the use of current
botanical keys for the genus Mentha. The use of "Mentha arvensis"
by the industry should be interpreted as a colloquial industry
usage for an "oil type" and not one of botanical specificity as
these plants are correctly botanically identified as M. canadensis.
For further information on mint species, see Lawrence, B. ed.,
2007. Mint: The Genus Mentha. CRC Press, Boca Raton, Fla.; see also
Tucker, A.O. and T. Debaggio, 2000. The Big Book of Herbs.
Interweave Press, Inc., Loveland, Colo.
The new mint plant of the present invention was developed in an
effort to cultivate a mint variety having a peppermint type oil and
flavor profile, and greater tolerance to Verticillium wilt
(Verticillium dahliae) and mint rust (Puccinia menthae) compared to
that of commercial peppermint (Mentha piperita). Furthermore,
`Metolius` produces a peppermint-type oil that varies minimally in
oil profile based on plant maturity.
The inventors explored ways of creating genetically distinct mint
plants through somatic hybridization of unpatented varieties of
Mentha canadensis and Mentha piperita. In 2002 `Metolius` was
created using this method. Specifically, the parental stock that
was used to create `Metolius` consisted of unpatented germplasms of
Mentha.times.piperita and Mentha canadensis species. The features
of `Metolius` are compared to the parent Mentha canadensis.
Since 2002, the plant has been under continuous evaluation at the
Applicants' facilities in Eugene, Oreg. and Sunnyside, Wash., as
well as under small-scale commercial programs located in Idaho,
Washington, and Eastern Oregon. Asexual propagation through stem
and rhizome cuttings have been successfully carried out many times
in Eugene, Oreg. and Sunnyside, Wash. The resulting propagules have
remained stable in appearance, oil quality, and other
characteristics to the original plant.
SUMMARY OF THE INVENTION
The present invention relates to a new and distinct mint plant
named `Metolius` characterized by a unique oil chemistry and flavor
profile resembling that of peppermint oil, and by its tolerance to
Verticillium wilt (Verticillium dahliae) and mint rust (Puccinia
menthae). Compared to `Shivalik` and `Kosi,` two commonly grown
commercial varieties of M. canadensis, the plant is slightly
shorter with darker green leaves when grown under similar growing
conditions. The leaves are also slightly longer and narrower
compared to `Shivalik.` It matures about the same time as
`Shivalik` and `Kosi.` The oil chemistry and flavor profile of
`Metolius` is also similar throughout its maturity when grown in
Oregon, Washington, and Idaho.
BRIEF DESCRIPTION OF THE PHOTOGRAPHS
The accompanying color photographs of `Metolius` show the new
variety:
FIG. 1: shows the flower spike of `Metolius`.
FIG. 2: shows the mature leaves of `Metolius`.
DETAILED DESCRIPTION OF THE INVENTION
The present invention `Metolius` is a new and distinct variety of a
Mentha canadensis plant having the following characteristics that,
in combination, are not exhibited in other M. canadensis
plants:
l-Menthone to d-Isomenthone ratio of around 4.5%, typical of that
found in commercial peppermint (Mentha piperita) oil. In other
commercial Mentha canadensis, this ratio is around 2.0% or
less.
l-Menthone of about 18% to 20%, compared to about 8% to 10% for
other commercial M. canadensis.
l-Menthol of about 62%, this compared to 42% and 72% for commercial
peppermint and other commercial M. canadensis respectively.
l-Limonene of about 2.5% compared to 1.5% and under 2.0% for
peppermint and other commercial M. canadensis respectively.
Oil having a clean peppermint-like flavor and odor profile.
When grown side by side with other commercial M. canadensis,
`Metolius` is a slightly shorter plant with leaves slightly darker,
shorter, and narrower.
Botanical Description
M. canadensis `Metolius` is an herbaceous perennial with an upright
shrubby growth habit. The plant physically spreads by stolons, and
it is reasonable for a single rooted cutting to spread and cover 3
4 square feet after one growing season. Numerous branching stems
are produced each year with an eventual height of 70 80 cm.
Compared to `Shivalik` (not patented) and `Kosi` (U.S. Plant Pat.
No. PP12,426), two commonly grown commercial cornmints, the plant
is slightly shorter with darker green leaves when grown under
similar growing conditions. The leaves are also slightly longer and
narrower compared to `Shivalik.` It matures about the same time as
`Shivalik` and `Kosi.`
`Metolius` has been grown in different field locations. It has also
been grown under greenhouse conditions. Asexual propagation through
stem and rhizome cuttings have been successfully carried out many
times since 2002 at the Applicants' facilities in Eugene, Oreg. and
Sunnyside, Wash. The resulting propagules have remained stable in
appearance, oil quality, and other characteristics to the original
plant. The basic morphological characteristics have remained
consistent, with any minor differences easily attributed to
differences such as climate, soils, fertilizer, or water regime.
The distinguishing traits present in `Metolius` remain constant in
the asexually reproduced plants.
Oil Composition and Flavor
Although `Metolius` has the same chemical components as other M.
canadensis varieties, the relative amount of several components
resembles the distribution typically found with peppermint oil. The
l-Menthone / d-Isomenthone ratio of about 4.5 for `Metolius` is
typical of a standard Mentha piperita which contributes to the
clean peppermint-like flavor characteristics noted with this oil.
The level of l-Menthone is about 18.0% for both `Metolius` and
commercial peppermint compared to 10% for other commercial M.
canadensis varieties. The level of l-Menthol is about 62%, for
`Metolius` compared with 42% and 72% for peppermint and other
commercial M. canadensis, respectively. The l-limonene level for
`Metolius` is about 2.5% compared to 1.5% and less than 2.0% for
peppermint and other commercial M. canadensis respectively.
Stem and Leaves:
`Metolius` has a square stem and therefore does not have a stem
diameter. The stem dimensions measure 8 9 mm long per side of the
square for a total dimension of 8 9 mm by 8 9 mm when mature.
Measurements were taken near the base of the stem, since this
measurement will decrease towards the tip of the plant. The plant
matures to approximately 70 80 cm in length. Internode length
varies considerably along the stem from less than 20 mm near the
base and at the apex, increasing to an average of 50 mm along the
midstem. Under crowded conditions, internode length can even be
higher, up to 80 mm. As a mint plant, `Metolius` spreads by
underground stolons and the number of stems is highly variable.
Stems and ovate leaves are pubescent, oppositely arranged on the
stem with an equilateral base, an acute apex, serrate margin and
decreasing in size towards the apex of a blooming stem. The average
mature leaf length is 60 mm. Average leaf width is 30 mm. Venation
pattern is pinnate. Dorsal leaf surface color is medium yellow
green (147A -- Yellow-Green Group), with a lighter ventral color
(147B -- Yellow-Green Group). Vein color is light yellow green
(147C -- Yellow Green Group). The mature petiole length is 6 8 mm.
Petiole width is 3 4 mm. Petiole thickness is 1 2 mm. Petiole color
is light yellow green (147C -- Yellow-Green Group). Stem color is
also light yellow green (146C -- Yellow-Green Group). Color numbers
are from The R.H.S. Colour Chart (Royal Horticultural Society
(Great Britain), London 1966). The base of the stem has a more
"woody" appearance and quality with more brownish coloring and
fissures. The fragrance is a clean peppermint-like aroma.
Flower:
Like other Mentha canadensis species, `Metolius` possesses a flower
spike with a pair of bract-like leaves subtending each
verticillaster. The individual flowers contain a 4-lobed, nearly
regular, mostly white, tubular corolla with a slight light purple
coloration near the base (85C -- Violet Group). The flower is 8 mm
long from the base of the calyx to the tip of the forked white
stigma. The calyx generally has five teeth fused at the base
forming a short tube and is 3 mm long. The calyx, peduncle and
pedicel colors are light yellow green (147C -- Yellow-Green Group).
Each flower has one pistil with an 8 mm long white style and four
epipetalous stamens that are exerted with 4 mm long white
filaments. The white anthers are less than 1 mm. Pollen is not
produced in abundance. That which is produced has a pale yellow
color. The formation of seed is a rare event. There is no obvious
flower fragrance.
The above description is based on observations of a field plot made
during the middle of the second growing season of the field plot
outdoors in western Oregon.
Genetic Analysis
In order to determine the precise genetic identity of `Metolius`,
DNA (SSR) microsatellite marker analysis was conducted using known
methods as described by T. A. Holton, Plant genotyping by analysis
of microsatellites 15 28, in Plant Genotyping: The DNA
fingerprinting of plants (R.H. Henry ed., 2001). Comparing
microsatellite DNA (SSR) methodologies with other DNA genotyping
techniques such as RFLPs, AFLPs, and RAPDs, has established that
microsatellite DNA (SSR) offers a more reliable, repeatable method
for characterization with an increased ability to differentiate
among plant varieties. The technique has been widely used in
animal, plant, and human identification and population studies. The
drawback of the technique is the initial high cost of developing
the markers. However, once these markers have been developed, they
can be simply used by combining PCR with GenScan technologies.
During 2003 2005 period, a project was conducted using 34
microsatellite markers to genetically identify `Metolius.` A total
of 4 different populations of M. canadensis were collected. Their
microsatellite DNA profiles were then compared against a total of 8
recognized peppermint varieties along with other closely related
Mentha species including spearmint (M. spicata).
A total of 179 microsatellite characters/profiles were found from
the 34 markers. Genetic distances as measured by total character
differences among different populations of the same variety ranged
from 0 14. The values among recognized peppermint varieties ranged
from 16 42. The values between `Metolius` populations and other M.
canadensis populations ranged from 0 4. A phylogenetic analysis was
conducted as well as a principal component analysis. Both revealed
that `Metolius` and M. canadensis populations clustered together
and formed a strongly supported M. canadensis species group. Based
on these genetic analyses, `Metolius` was classified as a variety
of M. canadensis. The differences observed among the M. canadensis
samples are typical of the differences noted among different
varieties of the same species, and allow the identification of
`Metolius` from other varieties of M. canadensis.
Plant Disease Resistance/Susceptibility
Observations of `Metolius` since 2002 indicate that rust does not
infect `Metolius` under any observed circumstances. Furthermore,
`Metolius` has exhibited high tolerance to Verticillum wilt through
the same observation period.
Winter Hardiness and Drought/Heat Tolerance
`Metolius` is winter hardy and heat tolerant in the common mint
growing regions of the world. No specific claims are made to
exceptional cold hardiness or heat tolerance.
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