U.S. patent application number 13/518789 was filed with the patent office on 2013-09-05 for dual purpose pollenizer watermelons.
This patent application is currently assigned to Nunhems B. V.. The applicant listed for this patent is Elena Chiapparino, Erik De Groot. Invention is credited to Elena Chiapparino, Erik De Groot.
Application Number | 20130232636 13/518789 |
Document ID | / |
Family ID | 45044577 |
Filed Date | 2013-09-05 |
United States Patent
Application |
20130232636 |
Kind Code |
A1 |
De Groot; Erik ; et
al. |
September 5, 2013 |
DUAL PURPOSE POLLENIZER WATERMELONS
Abstract
The application relates to the field of plant breeding, in
particular watermelon breeding. Provided are diploid watermelon
plants (and seeds from which these plants can be grown) which
produce small, diploid, red watermelon fruits. Also provided are
small, diploid watermelon fruits having an average weight of less
than 1.8 kg.
Inventors: |
De Groot; Erik; (Nonantola,
IT) ; Chiapparino; Elena; (Bologna, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
De Groot; Erik
Chiapparino; Elena |
Nonantola
Bologna |
|
IT
IT |
|
|
Assignee: |
Nunhems B. V.
AC Nenhem
NL
|
Family ID: |
45044577 |
Appl. No.: |
13/518789 |
Filed: |
November 23, 2011 |
PCT Filed: |
November 23, 2011 |
PCT NO: |
PCT/EP2011/070817 |
371 Date: |
July 20, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61416908 |
Nov 24, 2010 |
|
|
|
Current U.S.
Class: |
800/260 ;
426/616; 435/410; 47/58.1FV; 800/308 |
Current CPC
Class: |
A01H 5/00 20130101; A01H
6/78 20180501; A01H 5/08 20130101; A23L 19/00 20160801; A01G 22/00
20180201; A01H 6/342 20180501 |
Class at
Publication: |
800/260 ;
800/308; 435/410; 426/616; 47/58.1FV |
International
Class: |
A01H 5/08 20060101
A01H005/08; A01G 1/00 20060101 A01G001/00; A23L 1/212 20060101
A23L001/212 |
Claims
1. A plant of the species Citrullus lanatus, wherein said plant is
diploid and produces edible, mature diploid fruits having an
average weight of less than 0.9 kg.
2. The plant according to claim 1, wherein the mature diploid
fruits have an average fruit weight of equal to or less than 0.65
kilograms.
3. The plant according to claim 1, wherein the mature diploid
fruits have an average percent Total Soluble Solids (TSS) of at
least about 8%.
4. The plant according to claim 1 wherein the diploid fruits
comprise fruit flesh having a red color, with a RHS color chart
rating of 39 or higher.
5. The plant according to claim 1 wherein the plant produces at
least 30 male flowers 22 days from flowering.
6. The plant according to claim 1, wherein said plant produces an
average of at least 10 fruits per plant.
7. The plant according to claim 1, wherein the mature diploid
fruits have an average fruit length.times.width of less than or
equal to 10 cm.times.11 cm, or less at maturity of said fruit.
8. A diploid watermelon fruit obtainable from a plant according to
claim 1, wherein the weight of the mature fruit is less than 0.9
kg.
9. The diploid watermelon fruit according to claim 8, wherein the
mature fruit has an average weight of less than or equal to 0.65
kilograms.
10. A container comprising a plurality of fruits according to claim
8.
11. A watermelon plant or seed comprising the plant according to
claim 1 as male or female parent.
12. A transplant or vegetative propagation of a plant according to
claim 1.
13. Seeds or transplants from which a plant according to claim 1
can be grown.
14. The plant according to claim 1 obtainable from seeds deposited
under accession number NCIMB 41773.
15. A method for producing diploid and triploid watermelon fruits
in one field, said method comprising: (a) interplanting diploid
pollenizer plants according to claim 1 and triploid hybrid
watermelon plants in one field, (b) allowing pollination of flowers
of the triploid hybrid plants with pollen from diploid pollenizer
plants and allowing pollination of flowers of the diploid
pollenizer plants with pollen from the diploid pollenizer plants,
whereby pollination occurs, (c) harvesting fruits produced from the
triploid hybrid plants and, (d) optionally, further comprising
harvesting fruits produced from the diploid pollenizer plants.
16. A method for producing edible, diploid watermelon fruits having
an average weight of less than 0.9 kg, said method comprising: (a)
growing a plant according to claim 1, (b) pollinating the female
flower parts from said plant with pollen from said plant, and (c)
harvesting the fruits produced from said plant.
17. The method according to claim 16, wherein the plant comprises
genetic elements for producing small fruits having an average
weight of less than 0.9 kilograms and said genetic elements are
obtainable from seed deposited under accession number NCIMB
41773.
18. A diploid watermelon pollenizer plant producing small edible
fruits having an average weight of less than 0.9 kg, wherein the
watermelon comprises a representative sample of seeds, deposited
under accession number NCIMB 41773, comprising genetic elements for
producing the small fruits.
19. A seed of a diploid watermelon line capable of producing edible
fruit of less than 0.9 kg upon self-pollination, wherein a
representative sample of seed has been deposited under accession
number NCIMB 41773.
20. A plant cell, an ovule, pollen, a root-stock or a scion of a
plant according to claim 1.
21. The plant according to claim 1, wherein the plant is a
hybrid.
22. The plant according to claim 3, wherein the diploid fruits have
an average percent TSS of at least about 9%.
23. The plant according to claim 3, wherein the diploid fruits have
an average percent TSS of at least about 10%.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of watermelon
breeding and watermelon improvement. Provided are new diploid
watermelon plants (2n=2x=22) and seeds from which such plants can
be grown, which produce very small diploid fruits. The diploid
watermelon plants are preferably suitable as pollenizers in
triploid watermelon (2n=3x=33) production, whereby the pollenizers
therefore have a dual purpose: providing sufficient viable pollen
to pollinate female flowers of triploid plants (which after
pollination produce triploid, seedless watermelon fruits) and/or to
provide small ("mini"- or personal size), edible diploid fruits on
the pollinizer plants themselves.
BACKGROUND OF THE INVENTION
[0002] Seedless watermelon (Citrullus lanatus (Thunb.) Matsum. And
Nak.) production involves using pollen from diploid male parent
plants to fertilize flowers of tetraploid (2n=4x=44) maternal
parent plants. Pollination of the tetraploid flowers with diploid
pollen leads to hybrid F1 seeds which are triploid (Kihara, 1951,
Proceedings of American Society for Horticultural Science 58:
217-230; Eigsti 1971, Hort Science 6: 1-2). The triploid hybrid
plants, grown from these F1 seeds, are self-infertile as they
produce sterile pollen due to chromosome imbalance (Fehr, 1987).
The triploid hybrids, therefore, need to be pollinated by a diploid
pollenizer to produce watermelon fruit. Triploid plants are,
therefore, interplanted with pollenizer plants for fruit
production. The "seedless" fruit produced after pollination on the
triploid hybrid plant are often not truly seedless, but may contain
some undeveloped, small, pale seeds, which are edible.
[0003] For optimal seedless watermelon fruit set, sufficient viable
pollen is required. Plants are generally planted at a ratio of 1
pollenizer per every 2-4 triploid plants. Triploid plants and
pollenizers are either planted in separate rows (e.g. 1 row of
pollenizer and 2-4 rows of triploids), or interplanted within rows
(e.g. planting 1 pollenizer plant in between 2 to 3 triploid plants
in the same row), or interplanted in narrow rows between rows of
triploids (see US 2006/0168701 Table 2). The fruit produced on the
pollenizer plants preferably has a different rind pattern from the
fruit on the triploid hybrids, so that these can be easily
distinguished. Until now generally the fruits produced on dedicated
pollenizer plants are not harvested or discarded and only the
seedless triploid fruits are sold.
[0004] In the last years, several dedicated pollenizer plants have
been developed, which provide sufficient staminate flowers and
sufficient viable pollen throughout the season to increase triploid
fruit yield. These dedicated pollenizers include for example
varieties Polimax and Jenny (Nunhems), Sidekick (Harris Morin),
Companion (Seminis) and the Super-Pollenizers SP-1 and SP-4
(Syngenta). These dedicated pollenizers can be divided into two
categories based on their vegetative growth type, which is either
of the standard vine length e.g. Jenny and SP-1 and SP-4, or the
`compact` vine length, e.g. Companion or Sidekick.
[0005] Some pollenizers produce diploid fruits which could be
marketable, while others produce fruits that are unsuitable for
consumption and marketing. Dittmar (2006, MSc Thesis North Carolina
State University, Horticultural Science, Characterization of
diploid watermelon pollenizers and utilization for optimal triploid
watermelon production and effects of halosulfuron post and post-dir
on watermelon) evaluated different pollenizers for the potential
marketability of their fruits and concluded that Mickeylee, SF800,
MiniPool, Jenny and Pinnacle have a fruit quality that could
potentially be marketed. Average fruit weight of these was 5.1 kg,
10.7 kg, 3.9 kg, 3.3 kg and 2.9 kg respectively (Dittmar 2006,
supra). The smallest diploid fruits were produced by Sidekick (1.0
kg, with dimensions of 12.3.times.11.9 cm length:width Dittmar
2006, supra) and SP-1 (2.0 kg, with dimensions of 17.5.times.15.4
cm length:width (Dittmar 2006, supra), but neither of these produce
marketable fruits. The fruits of Sidekick are very poor quality
pink-fleshed and those of SP-1 are white-fleshed and have a low
brix value. Due to the non-marketable fruits, these pollenizers are
referred to as being "non-harvestable pollenizers".
[0006] US2009/0288183 (Gold Seed Co. LLC) describe a pollinizer
called "Escort-4" which produces small fruits having reduced sugar
for type 2 diabetics, referred to as a "dual purpose reduced sugar
watermelon". The fruits are said to have an average weight of 4.0
lbs (1.8 kg) and a size of 5-7 inches long (12.7-17.7 cm).times.4-5
inches wide (10.1-12.7 cm). The fruits of Escort-4 are said to have
approximately 1/3 less sugar content than commercial diploid
varieties, such as Sangria (Syngenta Inc.).
[0007] It is an object of the invention to provide dual purpose
watermelon pollenizers producing small, edible (i.e. marketable)
diploid fruit with an average fruit weight of less than 2.0 kg,
preferably less than 1.8 kg or 1.7 kg, more preferably equal to or
less than 1.6, 1.5, 1.4, 1.3, 1.0, 0.9, 0.8, 0.7 kg, and even more
preferably equal to or less than about 0.65 kg, such as equal to or
less than 0.6 kg, 0.5 kg, 0.4 kg or 0.3 kg. In one embodiment the
fruits are preferably red fleshed, more preferably dark red
fleshed, with a RHS rating of 39 or higher (not pink red or coral
red or yellow-red). In another embodiment the average fruit brix is
at least about 7.5% or higher.
[0008] It is a further object of the invention to provide dual
purpose watermelon pollenizers producing small, edible (i.e.
marketable) diploid fruit with an average fruit weight of less than
0.9 kg, such as equal to or less than 0.8 kg, 0.7 kg, 0.65 kg, 0.6
kg, 0.5 kg, 0.4 kg or 0.3 kg, but above 0.25 kg. In one embodiment
the fruits are preferably red fleshed, more preferably dark red
fleshed with a RHS rating of 39 or higher (not pink red or coral
red or yellow-red). In another embodiment the average fruit brix is
at least about 7.5% or higher.
General Definition
[0009] The verb "to comprise" and its conjugations is used in its
non-limiting sense to mean that items following the word are
included, but items not specifically mentioned are not excluded. In
addition, reference to an element by the indefinite article "a" or
"an" does not exclude the possibility that more than one of the
element is present, unless the context clearly requires that there
be one and only one of the elements. The indefinite article "a" or
"an" thus usually means "at least one", e.g. "a plant" refers also
to several cells plants, etc. Similarly, "a fruit" or "a plant"
also refers to a plurality of fruits and plants.
[0010] As used herein, the term "plant" includes the whole plant or
any parts or derivatives thereof, preferably having the same
genetic makeup as the plant from which it is obtained, such as
plant organs (e.g. harvested or non-harvested fruits, leaves,
etc.), plant cells, plant protoplasts, plant cell- or
tissue-cultures from which whole plants can be regenerated, plant
calli, plant cell clumps, plant transplants, seeds from which the
plant can be grown and seeds produced by the plant, seedlings,
plant cells that are intact in plants, plant clones or
micropropagations, or parts of plants, such as plant cuttings,
embryos, pollen, ovules, fruits (e.g. harvested tissues or organs),
flowers, leaves, clonally propagated plants, roots, stems, root
tips, grafts (scions and/or root stocks) and the like. Also any
developmental stage is included, such as seedlings, cuttings prior
or after rooting, etc.
[0011] It is, thus, understood that herein a watermelon plant, such
as a triploid plant or pollenizer plant, encompasses not only an
ungrafted plant, but also a plant with a rootstock of a different
plant, such as a gourd or squash rootstock, another watermelon
rootstock, a transgenic rootstock, etc.
[0012] As used herein, the term "variety" or "cultivar" means a
plant grouping within a single botanical taxon of the lowest known
rank, which can be defined by the expression of the characteristics
resulting from a given genotype or combination of genotypes.
[0013] The term "allele(s)" means any of one or more alternative
forms of a gene at a particular locus, all of which alleles relate
to one trait or characteristic at a specific locus. In a diploid
cell of an organism, alleles of a given gene are located at a
specific location, or locus (loci plural) on a chromosome. One
allele is present on each chromosome of the pair of homologous
chromosomes. A diploid plant species may comprise a large number of
different alleles at a particular locus. These may be identical
alleles of the gene (homozygous) or two different alleles
(heterozygous).
[0014] The term "locus" (loci plural) means a specific place or
places or a site on a chromosome where for example a gene or
genetic marker is found.
[0015] "Diploid plant" refers to a plant, vegetative plant part(s),
or seed from which a diploid plant can be grown, having two sets of
chromosome, designated herein as 2n.
[0016] "Triploid plant" refers to a plant, vegetative plant
part(s), or seed from which a triploid plant can be grown, having
three sets of chromosomes, designated herein as 3n.
[0017] "Tetraploid plant" refers to a plant, vegetative plant
part(s), or seed from which a tetraploid plant can be grown, having
four sets of chromosomes, designated herein as 4n.
[0018] "Pollenizer plant" or "pollenizer" refers to the (inbred or
hybrid) diploid plant, or parts thereof (e.g. its pollen or scion),
suitable as pollenizer for inducing fruit set on triploid plants. A
pollenizer plant is, thus, able to lead to good fruit set (and good
triploid fruit yield) of triploid plants, by producing an
appropriate amount of pollen at the appropriate day-time and for an
appropriate period of time, e.g. at least during peak flowering
time of the triploid female plants. A good triploid fruit yield is,
for example, a yield comparable to the yield obtainable when using
Polimax (produced by Nunhems) as pollenizer (see e.g. Example
3).
[0019] "Dual purpose pollenizer" refers to a pollenizer plant which
also produces edible diploid fruits on the pollenizer plant itself
(through self-pollination) and also is suitable to be used as a
pollenizer in triploid (seedless) watermelon production. This
definition is independent of whether or not the plant is actually
being used as a pollenizer in triploid fruit production, i.e. it
can also be used for diploid fruit production on its own.
[0020] The term "edible" is used herein to refer to fruits
marketable for human consumption, especially fresh consumption of
the fruit flesh. The fruits have at harvest at least good,
preferably very good flavor properties (i.e. taste and odor). To
have good flavor properties the fruits preferably have an average
level of Total Soluble Solids of at least about 7.5% or more. Good
fruit flesh color is also an important criterion for marketability
for human consumption. For red-fleshed fruits it is an embodiment
that the flesh color has an average RHS rating of at least 39 or
above. If red-fleshed fruits are measured on a scale of 1 (white)
to 10 (dark red), the fruits have an average rating of at least 7
or more.
[0021] "Hybrid triploid plant" is a triploid plant grown from
hybrid, triploid seed obtained from cross fertilizing a male
diploid parent with a female tetraploid parent.
[0022] "Seedless fruit" are triploid fruit which contain no or few
mature seeds. The fruit may contain one or more small, edible,
white ovules. Plants which produce seedless fruit may herein be
referred to as "seedless".
[0023] "Interplanting" refers to the combination of two or more
types of seeds and/or transplants sown or transplanted on the same
field, especially the sowing and/or transplanting of pollenizers in
the same field as triploid hybrid plants (for seedless fruit
production on the triploid plants and diploid fruit production on
the pollenizer plants). For example, the pollenizer may either be
planted in separate rows or interplanted with the triploid plants
in the same row (e.g. in hills within each row). Pollenizers may
also be planted in between rows of triploids. Also seeds of
pollenizers and triploid hybrids may be mixed prior to seeding,
resulting in random seeding. The transplants of the triploid hybrid
plants and/or pollenizer plants may also comprise a rootstock of a
different plant. Suitable rootstocks are known in the art. Also
encompassed are methods where the triploid hybrid plant and the
pollenizer plant are grafted together onto one rootstock.
[0024] "Planting" or "planted" refers to seeding (direct sowing) or
transplanting seedlings (plantlets) into a field by machine or
hand.
[0025] "Vegetative propagation" refers to propagation of plants
from vegetative tissue, e.g. by in vitro propagation or grafting
methods (using scions).
[0026] "Vegetative type" or "growth type" or "vine type" refers to
the combination of growth characteristics of the vegetative parts
of a plant line or variety, such as (average) internode length,
(average) length of the main vine, (average) length of the shortest
and longest branch, average number of primary branches, etc. Three
vegetative types can be distinguished: The "normal/standard vine
type", the "compact vine type" and an "intermediate vine type"
between these two.
[0027] "Compact vine type" refers to the vegetative type of a plant
or plant line or variety having an average internode length of
about 4.0-6.5 cm, especially an average internode length of equal
to or below 6.5 or 6.0 cm, e.g. equal to or below 5.0, 4.5 or 4.0
cm and/or an average longest branch of equal to or less than about
170 cm, preferably 160 cm, preferably equal to or less than 150 cm
or 145 cm, preferably equal to or less than 140 or 130 cm. Examples
of compact vine types are Companion and Sidekick (U.S. Pat. No.
7,314,79).
[0028] A "standard vine type" refers to the vegetative type of a
plant or plant line or variety having an average internode length
of more than 6.5 cm, preferably equal to or more than about 7, 8,
9, 10, 11 or 12 cm and/or an average longest branch of equal to or
more than 225 cm, e.g. equal to or more than 230 cm, 250 cm, 300
cm, 350 cm or more. Examples are varieties Ace, Jenny, SP-1,
SP-4.
[0029] An "intermediate vine type" refers to the vegetative type of
a plant or plant line or variety which falls between the standard
and compact vine type as defined above. It has an average internode
length of less than 10.5 cm, e.g. equal to or less than 10, 9, 8,
7, 6 or 5 cm, preferably about 6.0, 6.5, 7.0, 7.5, 8.0, 8.5 or 9.0
cm and/or an average longest branch of equal to or less than about
220 cm. The longest branch is on average preferably about 175-220
cm, e.g. preferably about 175, 180, 185, 190, 195, 200, 205, 210,
215 or 220 cm.
[0030] Throughout this document "average" and "mean" are used
interchangeably and refer to the arithmetic mean.
DETAILED DESCRIPTION
[0031] The invention provides plants (and seeds from which such
plants are grown) of the species Citrullus lanatus, wherein said
plant is suitable as a pollenizer in triploid watermelon
production, is diploid and produces marketable diploid fruits
having an average weight of less than 2.0 kg, preferably less than
1.8 kg, more preferably equal to or less than 1.7, 1.6, 1.5, 1.4,
1.3, 1.2, 1.0 kg, more preferably equal to or less than 0.9, 0.8,
0.7, 0.65 kg, such as equal to or less than 0.6, 0.5, 0.4, 0.35,
0.3 or 0.25 kg at harvest (i.e. at maturity). In a further
embodiment average fruit size is equal to or less than about 0.9 kg
(such as 0.8, 0.7, 0.65, 0.6, 0.5, 0.4 kg) but above 0.25 kg. To
determine average fruit characteristics, such as average fruit
weight, of a plant line or hybrid according to the invention
several plants of a line or hybrid are grown in one location and 3,
4, 5 or more fruits are harvested from 2, 3, or more plants of the
same line and e.g. weighed. Reference plant lines (such as known
pollenizers) can be grown at the same location (e.g. in the same
trial or under the same environmental conditions) as a comparison.
The average fruit weight according to the invention is in one
embodiment preferably less than 0.65 kg, more preferably equal to
or less than about 0.6, 0.5, 0.4, 0.3 or 0.25 kg. In another
embodiment the average fruit size is less than 0.65 kg but above
0.25 kg.
[0032] Fruit diameters can be variable, but preferably average
fruit length is less than 12 cm, more preferably equal to or less
than about 11.5 or 11 cm, such as equal to or less than 10.5, 10.0,
9.5, 9.0, 8.5 or 8.0 cm, while the average fruit width is
preferably less than 11, 10.5 or 10 cm, such as equal to or less
than 9.5, 9.0, 8.5, 8.0 cm. Thus, average fruit dimensions range
have ranges of 8.0-12.0 cm average length.times.8.0-11 cm average
width. Preferably at least fruit length is on average below 12 cm,
preferably below 11.5 cm, more preferably about 11 cm or less.
Preferably, both length and width of the fruits is on average about
11 cm or less. In one embodiment the average length by width is
10.times.11 cm, or less. In one embodiment average fruit dimensions
for both lengths and width are equal to or below 10.5 cm. These
dimensions are particularly encompassed for the diploid fruit
weights of less than 0.65 kg on average. For the heavier diploid
fruits (e.g. less than 1.8 kg but above 0.65 kg) also larger
dimensions are encompassed herein, such as an average length of
equal to or less than 17 cm (such as 16, 15, 14, 13, 12 cm) and an
average width of equal to or less than 15 cm, such as 14, 13, 12
cm).
[0033] The fruits, i.e. the fruit flesh, produced on the pollenizer
plants are edible at maturity. The flesh color of the mature fruits
of the diploid plants according to the invention is in one
embodiment red, having an RHS mini color chart value (Royal
Horticultural Society mini color chart) of 39 or higher, especially
between 39 and 41. Also, the average percent Total Soluble Solids
(% TTS; herein also referred to as degrees Brix, or .degree. Brix)
of the fruits is at maturity at least about 7.5%, preferably at
least about 8% or 8.5%, more preferably at least about 9% or 9.5%,
and even more preferably at least about 10%, 10.5%, 11%, 11.5%,
12%, 12.5%, 13%, or more. Average TSS can, for example, be
determined using a refractometer as described in the Examples. The
average percentage TSS of the diploid fruits produced by the
pollenizer plants according to the invention can be increased by
traditional breeding techniques, e.g. by crossing the plants
provided herein with watermelon plants comprising high TSS and
selection of progeny (e.g. obtainable by one or more selfings
and/or backcross populations) producing fruits with higher TSS
values while maintaining small fruit size.
[0034] As mentioned, the diploid fruits according to the invention
are edible, i.e. they have fruit quality characteristics which make
them marketable for human consumption. This means that the fruits
have good flavor properties (no off-flavors etc.). For fruits to
have at least good flavor properties a minimum average brix of at
least about 7.5 degrees is desired. Flavor properties can be
determined and scored (e.g. as bad, good, very good) by trained
test-panels using known methods for evaluating sensory properties
of fruits (Karen L. Bett, Ch 13, Fresh-Cut Fruits and Vegetables,
Science, Technology, and Market; Edited by Olusola Lamikanra, CRC
Press 2002, Print ISBN: 978-1-58716-030-1). Selection for good
flavor includes test panels to select against bitterness and other
unpleasant flavors, such as caramel flavor. Watermelon checks of
varieties which have good flavor properties (e.g. Allsweet, Crimson
Sweet) are preferably included in the test.
[0035] The fruits should preferably also not be susceptible to what
is known as "fruit cracking" and/or should preferably not contain
the brittle gene as present in SP-1. The Super Pollenizers such as
SP-1 (as described in WO03/075641) bear brittle fruits, which makes
the fruits (in particular the fruit flesh) unmarketable as fresh
produce (although the seeds contained within the fruits can be
harvested and marketed). Crack-resistance is generally selected for
during breeding (e.g. in field observations and/or using for
example pressure tests or other tests), as cracking is an undesired
fruit quality characteristic. See also Haikun et al. 2010, Acta
Hort. (ISHS) 871:223-230).
[0036] Other fruit characteristics can be introduced by traditional
breeding methods (see further below) and thereby combined with
pollenizers producing small, edible diploid fruits according to the
invention. For example plants can be selected which produce small,
edible fruits, as described above, with increased or reduced rind
thickness, increased or reduced rind brittleness, various skin/rind
colors (e.g. light green; dark green; green-striped with narrow,
medium or wide stripes; grey types; with or without spotting;
Golden yellow) and rind surfaces (e.g. furrowed or smooth surface),
flesh structure/flesh firmness, different fruit shapes (elongate,
oval, blocky, spherical or round), higher brix content, higher
lycopene and/or vitamin content, different sugar:acid ratios, very
good fruit flavour, etc. Also the combination of small edible
fruits with another flesh color than red is possible, for example
genetic determinants for yellow flesh or orange flesh or white
flesh may be introduced, e.g. by backcross breeding with another
color-type. See Guner and Wehner 2004, Hort Science 39(6):
1175-1182, in particular pages 1180-1181 describing genes for fruit
characteristics. Generally important breeding objectives are early
maturity, high fruit yield, high internal fruit quality (good
uniform color, high sugar, proper sugar:acid ratio, good flavor,
high vitamin and lycopene content, firm flesh texture, non-fibrous
flesh texture, freedom from defects such as hollow heart, rind
necrosis, blossom-end rot or cross stitch and good rind
characteristics and cracking-resistance).
[0037] Rind thickness is a characteristic which influences damage
during handling and transporting (too thin or too brittle rind),
but thin rinds may also be desirable for consumers. In one
embodiment the fruits have a thin rind, such as an average rind
thickness (measured on the side) of at least about 0.2 cm, 0.3 cm,
0.4 cm, but less than 0.5 cm, more preferably less than or equal to
0.4 cm. Thus in one embodiment the rind is thicker than the rind of
SP-4 fruit, but thinner than the rind of Polimax, and optionally
thinner than the rind of Sidekick fruit. For certain embodiments
thicker rinds may be desired and small fruits having a rind of 0.5
or more cm, such as 0.6 and 0.7 cm are also encompassed herein. The
rind of the fruits preferably does not crack easily (i.e. is
cracking-resistant), both in fruits with thin rinds and thick
rinds.
[0038] In one embodiment of the invention, the fruits preferably
also do not have a brittle rind and/or an explosive rind as
described in WO03/075641 on page 13 and 14, i.e. the fruits do not
break under pressure in the range of 90 to 140 g/mm.sup.2.
[0039] Flesh firmness of the diploid fruits is preferably at least
about 0.8 (average firmness in kg as in Example 1), more preferably
at least about 0.9, 1.0, or more. Flesh firmness can be increased
by e.g. crossing with watermelons having firmer fruit flesh and
selection for firmer flesh without increasing fruit size. Plants
producing fruits with ultra-firm flesh are, for example, described
in US2006/0005284.
[0040] The diploid plants provided herein are suitable as
pollenizers, which means that they produce sufficient pollen at the
right time of the day and for an appropriate period of time to
induce fruit set in triploid hybrids, leading to a (average)
triploid fruit yield at least comparable to that obtained when
using e.g. Polimax as pollinator. However, the plants according to
the invention need not be sold or marketed as pollenizer for
triploid fruit production and need not be used as pollenizer in
triploid fruit production. They may also be marketed and/or used
solely for diploid fruit production on their own.
[0041] In one embodiment the pollenizer plants preferably produce a
large number of male flowers at the appropriate time during
flowering of the triploid hybrids, preferably at least about 35
open male flowers at day 15 and/or at least about 30 open male
flowers at day 22 from the first day of flowering, although the
number of male flowers is not critical in determining triploid
fruit set, as long as sufficient pollen is produced by the
available male flowers to lead to good triploid fruit set. As the
pollenizer plants are also used for diploid fruit production, also
sufficient female flowers must be produced by the pollenizers to
ensure their dual purpose.
[0042] As can be seen in the Examples Table 3, many open male and
female flowers were present over the 3 week period counted. At the
flowering date (the date when more than 50% of the plant in the
plot has male/female flowers) the 11 pollenizer lines had on
average 12.6 open male and 3.9 open female flowers. Each line
generally had significantly more open male flowers than SP-4 and
Polimax. At day 15 and 22 from 1.sup.st day of flowering all lines
produce significantly more open male flowers than Sidekick, SP-4
and Polimax, all having at least 35 open male flowers at day 15 and
at least 30 open male flowers at day 22. However, Polimax is a very
good pollenizer for triploid hybrids, despite the fact that the
number of male flowers is significantly lower than in the hybrids
provided in the Examples. Polimax had only about 18 open male
flowers at day 15 and day 20. The pollenizers according to the
invention, therefore, may have a lower number of male flowers than
in the Examples in Table 3, e.g. plants having about the same
number of open male flowers as Polimax are encompassed herein, i.e.
pollenizers having at least about 15, 18, 20, 25, 30, or more open
male flowers at day 15 and/or at day 22 from the 1.sup.st day of
flowering are also an embodiment of the invention.
[0043] Also the number of open female flowers was good, indicating
that the pollinizers are indeed suitable for dual-purposes, i.e.
pollination and fruit production of triploid hybrids and/or
pollination and fruit production on the diploid plants themselves
(fruits produced by self-pollination of the pollenizer plant).
[0044] In one embodiment of the invention the pollenizer plants are
dual purpose pollenizer plants. In particular, the average number
of open male flowers at day 22 from flowering is at least 15, 18,
20, 25 or 30 or more.
[0045] In one embodiment the pollenizer plants according to the
invention are hybrid diploids (F 1 diploids) and not open
pollinated (OP).
[0046] In yet a further embodiment of the invention, the dual
purpose pollenizer plants are not of the "edible seed watermelon"
or "confectionary" type, as for example produced in variety San
Juan (Native Seeds). These types of watermelon are produced to
harvest the seeds for consumption or seed oil production and the
fruits produce large, black or red edible seeds with soft seed
coats, see e.g. Zhang 1996, Cucurbit Genetics Cooperative Report
19:66-67 (article 24) and Zhang and Wang, 1990, Cucurbit Genetics
Cooperative Report 13:43-44 (article 16). In contrast, the seeds
produced in the diploid fruits according to the invention are small
(preferably tomato seed size to medium seed size, but not large)
and are not suitable for seed harvest and seed consumption. In one
embodiment of the invention the seeds of the diploid fruits are on
average shorter than or equal to 5 mm in length, for example
shorter than or equal to 4 mm, 3.5 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm
or 1 mm in length.
[0047] The dual purpose pollenizer plants not only produce very
small, edible fruits, but also high numbers of marketable fruits.
In one embodiment a plant according to the invention produces at
maturity on average at least about 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20 or more fruits per plant, more preferably at least 25
fruits, more preferably at least about 27, 28, 29, 30, 35 or more
fruits.
[0048] The pollenizer plants according to the invention can be
combined with different vine types, such as compact vine type,
standard vine type or, most preferably an "intermediate" vine type
using normal breeding techniques. For example the pollenizers
according to the invention may be crossed with a standard vine type
and progeny may be selected which have an intermediate vine
type.
[0049] It is understood that it is also an object of the invention
to provide seeds from which the pollenizer plants described herein
can be grown. Also seedlings, scions and rootstocks, as well as
cells and tissues of the pollenizer plants are encompassed herein.
Such plant parts comprise the genetic determinants for producing
dual purpose pollenizer plants according to the invention. Thus
whole plants obtained from seedlings, scions and rootstocks, as
well as cells and tissues of the pollenizer plants retain all the
physiological and morphological characteristcs of the pollenizer
plants according to the invention when grown under the same
environmental conditions.
[0050] It is a further object of the invention to provide a
plurality of diploid watermelon fruits obtainable on a pollenizer
plant according to the invention as described above, and/or seeds
present in those fruits. Thus, in one embodiment, harvested diploid
fruits are provided, such as packaged whole fruits or fruit parts
and/or processed fruits or fruit parts.
[0051] Also progeny of the plants according to the invention are
provided herein, such as seeds obtainable by crossing a pollenizer
plant described herein with another watermelon plant and/or by
selfing a plant according to the invention to produce F1 seeds (and
F1 plants grown from these seeds, as well as fruit produced by
self-pollinating the F1 plants).
[0052] Further provided are plant cells, cell cultures or tissue
cultures of plants according to the invention, as well as root
stocks, scions, transplants and vegetative propagations of plants
according to the invention or of progeny thereof.
[0053] In one aspect, a representative sample of seeds of the
plants according to the invention are deposited under accession
number . . . (WH 9306), or accession number NCIMB 41773 (WH9307),
or accession number . . . (WH9308), or accession number . . .
(WH9309), or accession number . . . (WH9311), or accession number .
. . (WH9313), or accession number . . . (WH9317), or accession
number . . . (WH9318), or accession number . . . (WH9319), or
accession number . . . (WH9320), or accession number . . .
(WH9321).
[0054] Plants having the genetic determinants for producing small,
edible fruits are, therefore, obtainable from the deposited seeds.
The genetic determinants (i.e. the combination of genes) for
producing small, edible fruits can be transferred to other
watermelon plants, for example to create other diploid pollenizers
with this phenotype or other diploids (open pollinated or inbred
lines, or hybrid diploids). This can be done by using the
pollenizers according to the invention as a parental line in
breeding methods, i.e. as male or female parent in a cross with
another watermelon plant. Known breeding methods can be used alone
or in combination, such as (but not limited to) recurrent
selection, pedigree breeding, backcross breeding, inbred
development, hybrid testing, marker assisted breeding, etc.
Diploids may also be used for tetraploid development, using e.g.
colchicine treatment. Progeny are then selected which retain the
small fruit dimensions and fruit weight, a brix of at least 7.5%
and dual purpose pollenizer characteristics, all as described
herein.
[0055] Other watermelon plants may be used as a starting point to
develop dual purpose pollenizer plants producing small, edible
fruits according to the invention. For example, small fruited
cultivars or lines may be used as starting material, such as for
example Sidekick (U.S. Pat. No. 7,314,979) and/or SP-1 (WO
03/075641) and/or watermelon plants carrying the "tomato seed"
mutant (gene ts) described in Guner and Wehner (2004, HortScience
39(6):1175-1182) and obtainable from gene curator of the Cucurbit
Genetics Cooperative), and selecting for fruit quality
characteristics (e.g. high brix, good flavor), small fruit size
(e.g. small fruit dimensions and e.g. less than 0.9 kg weight) and
small seed size in the diploid fruits, as well as pollenizer
characteristics (e.g. many male flowers) as described herein.
[0056] Selection for small seed size encompasses selecting for an
average seed length of equal to or less than 8 mm, preferably 7 mm,
6 mm or more preferably equal to or less than 5.0 mm, preferably
equal to or less than 4.5 mm, e.g. equal to or less than about 4.0
mm, 3.5 mm, 3.0 mm, 2.5 mm or 1.5 mm or 1.0 mm seed length.
[0057] In one embodiment a breeding method for producing diploid
dual pupose pollenizers according to the invention is provided,
comprising: [0058] a) providing a breeding population of diploid
watermelon plants, and [0059] b) selecting progeny for small fruit
size, small seed size, high brix, good flesh color and pollenizer
characteristics (all as described throughout this application).
[0060] Plants obtainable by this method are encompassed herein. As
mentioned, the breeding population can be provided by using at
least one, preferably two small-fruited parents and crossing these,
to generate an F1 and further progeny generations (F2, etc.). For
example, one of the plants provided herein (e.g. WH9307) is used in
step a) and is crossed to another watermelon plant. The progeny
generations are then selected for at least the characteristics
described in b).
[0061] In one embodiment one or more hybrid plants is provided,
obtained from crossing a pollenizer plant according to the
invention with another watermelon plant and harvesting the F1 seeds
of said cross. The F1 seeds may then be grown into F1 plants and
self pollinated or sib-pollinated to produce F2 seeds. If the
parents used in the initial cross differ by one or more
characteristics (e.g. disease resistance and fruit size), the F2
population will segregate for these trait(s) and the breeder can
select plants in this and/or further progeny generations (F3, F4,
etc.) which combine the desired traits (e.g. small fruit size and
disease resistance). Alternatively, the F1 may be backcrossed to
the recurrent parent (e.g. the pollenizer according to the
invention into which a trait is to be introduced) or the F1 may be
selfed to produce an F2 population segregating for the trait of
interest and selected F2 plants having the trait of interest may be
backcrossed to the recurrent parent.
[0062] Thus, one or more traits not present in the pollenizer
plants according to the invention can be introduced into a
pollenizer plant according to the invention, while maintaining the
genetic determinants for small diploid fruits. For example other
fruit characteristics as described above can be introduced (e.g.
darker red flesh color, higher brix, firmer flesh, a different
flesh color, etc.), or any other traits can be introduced, such as
one or more QTLs for high yield, disease resistance genes, stress
tolerance genes (e.g. water stress tolerance), etc. resistance to
fungal-, bacterial-, viral-diseases, root-knot nematodes and/or
insect pests may be introduced. For example, resistance to Fusarium
wilt (Fusarium oxysporum fsp. niveum race 0, race 1 and/or race 2,
and/or race 3, and/or other new races which may develop),
Anthracnose (Colletotrichum lagenarium races 1-7, or other new
races), Gummy stem blight, powdery mildew, Verticillium wilt,
bacterial fruit blotch, papaya ringspot virus (PRSV), watermelon
mosaic virus (WMV) or zucchini yellow mosaic virus (ZYMV).
[0063] Resistance to Fusarium wilt races 0 and 1 is present in many
commercial varieties, and also resistance to race 2 has been
identified in PI296341 and PI271769 and is also present in SP-4
(U.S. Pat. No. 7,550,652). Anthracnose resistance to race 1 is for
examples present in SP-4 and resistance to race 2 in AU-Sweet
Scarlet (AW-82-50CS) (Breeder: Alabama Agric. Expt. Station, Auburn
University). Crimson Sweet has the Ar-1 gene, which provides
resistance to anthracnose races 1 and 3. Gummy stem blight
resistance is also found in Plant Introduction lines.
[0064] Also provided is a method for producing diploid and triploid
watermelon fruits in one field, said method comprising: [0065] (a)
interplanting diploid pollenizer plants according to the invention
and triploid hybrid plants in one field, [0066] (b) allowing
pollination of flowers of the triploid hybrid plants with pollen of
the diploid pollenizer plants and allowing pollination of flowers
of the diploid pollenizer plants with pollen of the diploid
pollenizer plants, [0067] (c) harvesting fruits produced on the
triploid hybrid plants and, optionally, harvesting fruits produced
on the diploid pollenizer plants.
[0068] In one embodiment of the invention the diploid fruits and/or
the triploid fruits are edible and red-fleshed, white-fleshed,
orange-fleshed or yellow-fleshed.
[0069] In a further embodiment the rind of the diploid fruits is
not yellow or Golden (as controlled by the recessive gene go)
(Barham 1965, Proc Ameri Soc Hort Sci 67: 487-489).
[0070] Interplanting in one field may be either done by seeding or
transplants of the pollenizer and triploids. Various interplanting
methods can be used, as known in the art and various ratios of
pollenizer:triploid hybrid may be used. One row of pollenizer
plants may for example be present at at least every 2, at least
every 3 or at least every 4 rows of triploids, but other methods of
interplanting may also be used.
[0071] Any triploid hybrid may be used, such as known triploid
hybrid varieties.
[0072] Pollination is usually done by bees, and bee hives can be
provided to the fields unless sufficient wild bees are naturally
present. Pollination can also be performed by manual or mechanical
means. Harvest at maturity may be done by hand or mechanized.
[0073] The diploid fruit may be distinguished from the triploid
fruit based on the smaller fruit size of the diploid fruit, and/or
alternatively by a different rind pattern. In one embodiment the
rind of the diploid fruits according to the invention is not yellow
or golden. Preferably harvested diploid and triploid fruit are
placed into different containers. Thus, in one embodiment a
container comprising solely small diploid fruits according to the
invention is provided. Any type of container may be used, e.g.
cartons, boxes, etc.
[0074] Also a method for producing small diploid edible watermelon
fruits having an average weight of less than 1.8 kg, 1.7 kg, 1.0
kg, 0.9 kg, 0.8 kg, 0.7 kg, preferably equal to or less than 0.65
kg (but in one embodiment larger than 0.25 kg), is provided
comprising: [0075] (a) growing a plant according to the invention,
i.e. a pollenizer as described herein, [0076] (b) pollinating the
female flowers of said plant with pollen of said plant, [0077] (c)
harvesting the fruits produced on said plant.
[0078] Thus, by self-pollination of a diploid plant according to
the invention, small edible diploid fruits are produced. The
pollenizers according to the invention may be grown in a field
without other watermelon plants being present, and the small
diploid fruits may be harvested and placed in containers for
transport. Step (b) may be performed by allowing insect pollination
or any other means of pollinating.
[0079] In one embodiment a diploid pollenizer plant (or a seed from
which the plant can be grown) capable of producing small edible
diploid fruits having an average weight of less than 1.8 kg, 1.7
kg, 1.0 kg, 0.9 kg, 0.8 kg, 0.7 kg or equal to or less than 0.65 kg
(but in one embodiment larger than 0.25 kg) is provided, wherein a
representative sample of seed containing the genetic elements for
producing said small fruits has been deposited under accession
number . . . (WH 9306), or accession number NCIMB 41773 (WH9307),
or accession number . . . (WH9308), or accession number . . .
(WH9309), or accession number . . . (WH9311), or accession number .
. . (WH9313), or accession number . . . (WH9317), or accession
number . . . (WH9318), or accession number . . . (WH9319), or
accession number . . . (WH9320), or accession number . . .
(WH9321).
[0080] Especially, pollenizer hybrid WH 9307 comprises the genetic
elements for producing said small, edible fruits according to the
invention and a representative sample of seeds have been deposited
under accession number NCIMB 41773. Thus, when referring herein to
seed deposits of pollenizers according to the invention, this
pollenizer is referred to as a representative plant according to
the invention, but seeds of the other hybrids or lines are also
suitable and when reference to WH9307 or progeny thereof (or parts
of any of these) is made, the other hybrids or lines mentioned
herein are equally implied.
[0081] In one embodiment a hybrid watermelon seed is provided,
having as a male or female parent (preferably as a male parent) a
diploid pollenizer plant capable of producing small edible diploid
fruits having an average weight of less than 1.8 kg, 1.7 kg, 1.0
kg, 0.9 kg, 0.8 kg, 0.7 kg or equal to or less than 0.65 kg (but in
one embodiment larger than 0.25 kg) is provided, wherein a
representative sample of seed containing the genetic elements for
producing said small diploid fruits has been deposited under
accession number . . . (WH 9306), or accession number NCIMB 41773
(WH9307), or accession number . . . (WH9308), or accession number .
. . (WH9309), or accession number . . . (WH9311), or accession
number . . . (WH9313), or accession number . . . (WH9317), or
accession number . . . (WH9318), or accession number . . .
(WH9319), or accession number . . . (WH9320), or accession number .
. . (WH9321).
[0082] In one embodiment the fruit of a cross-pollination between a
diploid pollenizer plant as pollen donor capable of producing small
diploid fruits having an average weight of less than 1.8 kg, 1.7
kg, 1.0 kg, 0.9 kg, 0.8 kg, 0.7 kg or equal to or less than 0.65 kg
(but in one embodiment larger than 0.25 kg) is provided, wherein a
representative sample of seed containing the genetic elements for
producing said small fruits has been deposited under accession
number . . . (WH 9306), or accession number NCIMB 41773 (WH9307),
or accession number . . . (WH9308), or accession number . . .
(WH9309), or accession number . . . (WH9311), or accession number .
. . (WH9313), or accession number . . . (WH9317), or accession
number . . . (WH9318), or accession number . . . (WH9319), or
accession number . . . (WH9320), or accession number . . .
(WH9321), and the pistillate flowers of another watermelon plant is
provided. The other watermelon plant is preferably a triploid
hybrid and the fruit is triploid and preferably seedless.
[0083] In one embodiment a diploid fruit and/or an inbred diploid
seed is provided produced by self pollinating a diploid pollenizer
plant capable of producing small edible diploid fruits having an
average weight of less than 1.8 kg, 1.7 kg, 1.0 kg, 0.9 kg, 0.8 kg,
0.7 kg or equal to or less than 0.65 kg (but in one embodiment
larger than 0.25 kg) is provided, wherein a representative sample
of seed containing the genetic elements for producing said small
diploid fruits has been deposited under accession number . . . (WH
9306), or accession number NCIMB 41773 (WH9307), or accession
number . . . (WH9308), or accession number . . . (WH9309), or
accession number . . . (WH9311), or accession number . . .
(WH9313), or accession number . . . (WH9317), or accession number .
. . (WH9318), or accession number . . . (WH9319), or accession
number . . . (WH9320), or accession number . . . (WH9321).
[0084] In one aspect of the invention plants according to the
invention and fruits according to the invention are obtainable from
WH 9306, WH9307, WH9308, WH9309, WH9322, WH9313, WH9317, WH9318,
WH9319, WH9320, WH9321, or of progeny of any of these.
[0085] Plants obtained (derived), or obtainable (derivable), from
plants according to the invention (e.g. from deposited seeds)
include, therefore, plants obtained by breeding methods, such as
selfing, crossing, backcrossing, recurrent selection, double
haploid production, marker assisted selection, clonal propagations,
transformants, etc., whereby the derived plants produce small,
edible fruits according to the invention.
[0086] In another aspect of the invention plants having essentially
all the morphological and/or physiological characteristics of WH
9306, WH9307, WH9308, WH9309, WH9322, WH9313, WH9317, WH9318,
WH9319, WH9320, WH9321, or of progeny of any of these, are
provided. Representative examples of physiological and
morphological characteristics are provided in Tables 1-5.
[0087] Also provided is a progeny plant of WH 9306, WH9307, WH9308,
WH9309, WH9322, WH9313, WH9317, WH9318, WH9319, WH9320 or WH9321,
obtained by further breeding with said plant, wherein said progeny
plant has essentially all physiological and morphological
characteristics of said plant.
[0088] Essentially all physiological and morphological
characteristics include herein at least small, edible fruits and
dual purpose pollenizer characteristics as described throughout the
description and examples.
[0089] Also a plant part (e.g. a fruit, tissue, cell, cell culture,
vegetative propagation, pollen, etc.) is provided which, when
regenerated or grown into a whole plant, has essentially all the
morphological and/or physiological characteristics of WH 9306,
WH9307, WH9308, WH9309, WH9322, WH9313, WH9317, WH9318, WH9319,
WH9320 or WH9321.
[0090] Also provided is a plant derived from any of WH 9306,
WH9307, WH9308, WH9309, WH9322, WH9313, WH9317, WH9318, WH9319,
WH9320 or WH9321, having one or two physiological and/or
morphological characteristics which are different from the WH plant
listed and which otherwise has essentially all physiological and
morphological characteristics of a plant designated WH 9306,
WH9307, WH9308, WH9309, WH9322, WH9313, WH9317, WH9318, WH9319,
WH9320 or WH932, obtainable by further breeding with the WH plant
and/or by selecting a natural or induced mutant, or a somaclonal
variant from a population of plants designated WH 9306, WH9307,
WH9308, WH9309, WH9322, WH9313, WH9317, WH9318, WH9319, WH9320 or
WH9321.
Deposit Information
[0091] Applicant(s) maintain a deposit of at least 2500 seeds of
hybrid pollenizers mentioned in the Examples, and parent inbred
lines, at Nunhems B. V. Applicant has deposited hybrid WH 9307 at
the NCIMB on 12 Nov. 2010 under Accession number NCIMB 41773.
Access to this deposit will be available during the pendency of
this application to persons determined by the Commissioner of
Patent and Trademarks to be entitled thereto upon request.
[0092] Subject to 37 C.F.R. .sctn.1.808(b), all restrictions
imposed by the depositor on the availability to the public of one
or more deposits will be irrevocably removed upon the granting of
the patent by affording access to a deposit of at least 2500 seeds
with the American Type Culture Collection (ATCC), 10801 University
Boulevard, Manassas, Va. 20110 or National Collections of
Industrial, Food and Marine Bacteria (NCIMB), 23 St. Machar Drive,
Aberdeen, Scotland, AB24 3RY, United Kingdom. The deposit will be
maintained for a period of 30 years, or 5 years after the most
recent request, or for the enforceable life of the patent whichever
is longer, and will be replaced if it ever becomes nonviable during
that period. Applicant does not waive any rights granted under this
patent on this application or under the Plant Variety Protection
Act (7 USC 2321 et seq.).
[0093] The following non-limiting Examples describe the production
of diploid pollenizers and small, edible diploid fruits according
to the invention. Unless stated otherwise in the Examples, methods
for conventional watermelon breeding are used, such as e.g.
described in Maynard 2001, Watermelons--Characteristics, Production
and Marketing, ASHS Press; Mohr H. C. Watermelon Breeding in Mark
J. Bassett (editor) 1986 Breeding Vegetable Crops, AVI Publishing
Company.
EXAMPLES
Example 1
Breeding History
[0094] Breeding for the hybrids goes back to 1985, to in-house
breeding lines and crosses of these with the variety Allsweet.
Selected self pollinations were backcrossed with Tomato Seed OP
(Sugar Baby mutant; is gene) and selections were made for red flesh
and small seed. Further self pollinations were selected for red
flesh, small seeds and agronomic traits in general. Selections were
crossed with a line with many male flowers, followed by several
selfings and selection for the production of many male flowers and
small red fruits.
Example 2
Pollenizer Characteristics
2.1--Materials and Methods
[0095] A field trial was conducted in Italy (Sant'Agata
Bolognese-BO). Seeds were sown on 7 Apr. 2010 and transplanted into
the field on 21 May 2010 (100 cm within the row, 250 cm between the
rows). The plot contained 10 plants per line. Fruits were harvested
on 26/27 Jul. 2010 for evaluation.
2.1.1 Flowering
[0096] The number of open male and female flowers were counted for
three plants per line on the flowering date (day 1=24 Jun. 2010),
and 8, 15 and 22 days after the flowering date (day 8=2 Jul. 2010;
day 15=9 Jul. 2010; day 22=16 Jul. 2010). The mean number of three
plants per line was calculated.
2.1.2 Fruits
[0097] 1) Average fruit number: at maturity (26/27 July) the total
number of fruits harvested from two plants was counted and the
average fruit number determined. [0098] 2) Average fruit weight:
mean of the weight of three fruits per line randomly harvested from
two plants at maturity [0099] 3) Brix: Value is the mean of three
reading for three fruit, collected between the centre and the rind
of the fruit; expressed in Degrees Brix (.degree.) using the K71901
portable refractometer Mod. RLC ATC 0-18% (OPTECH). [0100] 4) Flesh
structure (flesh firmness): Value is the mean of the reading of
three fruits; expressed in kg using the fruit pressure tester FT
011 (Cientec Instrumentos) [0101] 5) Flesh colour: evaluated using
the Royal Horticultural Society mini colour chart
(http://www.rhs.org.uk/Plants/RHS-Publications/RHS-colour-charts)
2.1.3 Other Fruit Characteristics
[0102] Measurements were done for three fruits:
1) Fruit length (cm), indicated as FRT-cm_L 2) Fruit diameter at
midsection (cm), indicated as FRT-cm_D 3) Fruit rind thickness
(cm), blossom end, indicated as RND-cm_BE 4) Fruit rind thickness
(cm), side of fruit, indicated as RND-cm_S.
[0103] Rind thickness is measured from the outer edge of the fruit
to the boundary between white mesocarp and colored endocarp.
2.2--Results
2.2.1--Fruit Characteristics
[0104] Table 1 shows that the pollenizers according to the
invention produced very small, red, edible fruits.
TABLE-US-00001 TABLE 1 Fruit characteristics of fruits from 11
diploid pollenizers according to the invention and commercial
diploid pollenizers (Sidekick, SP-4 and Polimax) Dual Purpose
Average Fruit Pollenizers fruit flesh Flesh (diploid Average weight
structure color hybrids) fruit no. (kg) .degree. Brix (kg) (RHS) WH
9306x 38.5 0.52 7.0 0.6 Red (41A) WH 9307x 41.0 0.55 8.5 1.4 Red
(41A) WH 9308x 51.0 0.44 7.7 0.6 Red (41B) WH 9309x 38.5 0.45 8.0
0.6 Red (41A) WH 9311x 56.5 0.55 7.3 0.6 Red (41B) WH 9313x 23.5
0.59 6.3 0.5 Red (39B) WH 9317x 51.5 0.45 5.7 0.6 Red (41B) WH
9318x 34.5 0.51 7.7 0.6 Red (39B) WH 9319x 52.5 0.57 7.3 0.6 Red
(39B) WH 9320x 35.5 0.49 7.7 0.5 Red (41B) WH 9321x 49.5 0.33 6.2
0.5 Red (39B) Min-Max 23.5-56.5 0.33-0.59 5.7-8.5 0.5-1.4 Red (RHS
(average) (43.0) (0.49) (7.2) (0.6) 39B-41A) Commercial
pollenizers: Sidekick 27.5 0.75 7.7 0.6 Pink (31D) SP-4 8.5 1.4 5.2
1.1 white Polimax 5.0 2.3 10.3 1.0 red
[0105] As can be seen from Table 1, the diploid pollenizers
according to the invention produced very small, red-fleshed edible
fruits. Fruit weight in Table 1 is significantly smaller than that
of commercial pollenizers such as Sidekick, SP-4 and Polimax.
TABLE-US-00002 TABLE 2 Fruit dimensions Pollenizers Average length
(cm) Average width (cm) (diploid hybrids) (FRT-cm_L) (FRT-cm_D) WH
9306x 11.33 10.17 WH 9307x 10.50 9.83 WH 9308x 10.50 9.67 WH 9309x
11.00 10.00 WH 9311x 10.38 9.88 WH 9313x 11.33 10.00 WH 9317x 10.83
9.17 WH 9318x 11.17 9.67 WH 9319x 10.67 9.33 WH 9320x 11.33 9.17 WH
9321x 9.67 8.67 Commercial pollenizers: Sidekick 12.00 11.33 SP-4
15.33 13.17 Polimax 16.50 16.00
[0106] Table 2 shows that the pollenizers according to the
invention have on average smaller fruit dimensions than the
commercial pollenizers. The fruit length is on average 11.33 cm or
smaller, while in Sidekick the average fruit length is 12 cm. The
diameter is also smaller, only 10.17 cm or less, compared to 11.33
cm in Sidekick. Thus fruit dimensions of equal to or below
11.33.times.10.17 cm (e.g. even as small as 9.67.times.8.67 cm) are
significantly smaller than 12.00.times.11.33 cm in Sidekick.
[0107] Table 3 shows mean rind thicknesses per line, measured at
two points of the fruit. Thin rinds are an advantage for
consumption.
TABLE-US-00003 TABLE 3 rind thickness at the blossom end and on the
side of the fruit Average rind Average rind thickness - thickness -
Pollenizers blossom end (cm) side (cm) (diploid hybrids)
(RND-cm_BE;) (RND-cm_S) WH 9306x 0.17 0.37 WH 9307x 0.27 0.43 WH
9308x 0.20 0.37 WH 9309x 0.20 0.40 WH 9311x 0.25 0.40 WH 9313x 0.23
0.47 WH 9317x 0.15 0.33 WH 9318x 0.20 0.30 WH 9319x 0.23 0.40 WH
9320x 0.20 0.40 WH 9321x 0.13 0.30 Commercial pollenizers: Sidekick
0.30 0.43 SP-4 0.10 0.10 Polimax 0.40 0.70
[0108] The pollenizers according to the invention have good,
although thin, rind thickness of between 0.30 and 0.47 cm. The rind
is also not susceptible to cracking, giving the fruits good
handling properties. Fruits do also not have a brittle or explosive
rind.
[0109] The rind pattern of the fruits of all pollenizers according
to the invention is a Crimson Sweet type rind pattern
(medium-striped or netted), but the small fruit size can also be
combined with other rind colors using standard breeding
methods.
2.2.2--Flowering Characteristics
TABLE-US-00004 [0110] TABLE 4 Flowering characteristics of 11
diploid pollenizers according to the invention and commercial
diploid pollenizers (Sidekick, SP-4 and Polimax) No. of open male
flowers No. of open female flowers Pollenizer Day 1 Day 8 Day 15
Day 22 Day 1 Day 8 Day 15 Day 22 WH 9306x 18.3 48.3 49.0 35.7 4.7
2.0 0.0 1.3 WH 9307x 15.0 51.0 53.7 35.0 4.7 3.0 0.3 1.0 WH 9308x
12.3 45.0 36.0 41.7 4.3 4.7 0.0 2.0 WH 9309x 10.0 42.3 49.7 46.7
2.0 1.0 0.3 2.3 WH 9311x 11.7 54.7 57.0 61.7 1.3 6.3 0.7 3.0 WH
9313x 9.0 57.3 47.7 40.3 5.0 2.7 0.3 1.3 WH 9317x 12.0 56.7 68.3
82.3 5.0 4.7 0.7 5.3 WH 9318x 7.0 38.7 65.3 68.7 4.7 5.7 0.0 5.3 WH
9319x 18.3 71.7 54.3 56.7 3.7 3.3 0.3 1.3 WH 9320x 12.0 43.7 47.7
33.3 3.3 2.0 0.0 0.7 WH 9321x 13.3 42.7 65.0 56.7 4.3 5.3 0.0 3.3
Min-Max 7.0-13.8 38.7-71.7 36.0-68.3 33.3-82.3 1.3-5.0 1.0-6.3
0.0-0.7 0.7-5.3 (average) (12.6) (50.2) (54.0) (50.8) (3.9) (3.7)
(0.2) (2.5) Commercial pollenizers: Sidekick 14.3 46.3 33.0 24.3
2.0 4.7 0.0 0.0 SP-4 13.3 11.7 29.7 28.7 2.3 1.3 2.3 1.0 Polimax
14.3 10.0 18.3 18.7 1.3 1.7 1.3 1.3
2.2.3--Vegetative Types
[0111] The hybrids have a relatively compact growth type, with the
(average/pollenizer line of the) longest branch falling between
113.5 and 180.0 cm long and the shortest branch being between 57.0
and 80.0 cm long. The average number of primary branches per
pollenizer line was between 3 and 3.5. The average number of
secondary branches per pollenizer line at 30 cm and at 90 cm was
between 56.0 and 88.5 (at 30 cm) and between 77.5 and 144.0 cm.
Internode length ranged between 4.3 and 5.3 on average, depending
on the line. Leaf length and width is also relatively compact, with
leaf widths between 7.1 and 9.4 cm and lengths between 7.8 and 9.1
cm.
Example 3
Use of Pollenizers According to the Invention
3.1--Trial Set-Up
[0112] Three trials were carried out in Spain using pollenizers
WH9317x, WH9318x, WH9320x and WH9321x for triploid fruit production
on the triploid hybrid variety `Fashion`.
Trial 1:
[0113] Location: green house Trial dimensions: 3600 m.sup.2
Transplanting date: 19 Mar. 2010 Harvest date: 16 Jun. 2010 Scheme:
pollenizers and triploids were in separate rows, alternating one
row of triploid and one row of pollenizer. Distance between rows
was 3 meter, distance between plants in a row was 1 meter.
Trial 2:
[0114] Location: open field Trial dimensions: 2500 m.sup.2
Transplanting date: 24 Mar. 2010 Harvest date: 6 Jul. 2010 Scheme:
pollenizers and triploids were interplanted in the same rows, with
pollenizers making up 25% of the total plants. Distance between
rows was 3 meters and distance between plants in a row was 1
meter.
Trial 3:
[0115] Location: open field Trial dimensions: 1500 m.sup.2
Transplanting date: 20 Mar. 2010 Harvest date: 2 Jul. 2010 Scheme:
pollenizers and triploids were interplanted in the same rows, with
pollenizers making up 25% of the total plants. Distance between
rows was 2 meters and distance between plants in a row was 1.8
meter.
3.2--Trial Results
TABLE-US-00005 [0116] TABLE 5 mean value* of the triploid fruit
weight (kg) of Fashion (triploid hybrid) for three trials carried
out in three locations in Spain 2010 Trial 1 Trial 2 Trial 3
WH9317x 5.14 4.18 4.27 WH9318x 5.06 4.48 4.12 WH9320x 5.22 3.94
4.23 WH9321x 4.65 4.35 4.30 Average 5.02 4.24 4.23 (min-MAX)
(2.5-9.08) (2.5-7.64) (2.56-7.60) Commericial Pollenizers Jenny
5.15 4.26 4.96 Polimax 5.30 3.90 4.54 SP-4 6.14 4.26 4.44 Sidekick
5.35 *Mean value: mean of the weights of the total marketable
triploid fruits (>2.5 kg) harvested in an area of 60 m.sup.2, 90
m.sup.2 and 30 m.sup.2 of the Trial 1, Trial 2 and Trial 3,
respectively.
* * * * *
References