Fragaria plants and seeds

Polyploid Fragaria plants propagatable from seed wherein substantially each plant is capable of a fruit productivity within its first year, F1 hybrid Fragaria plants, methods for producing F1 hybrid Fragaria plants, F1 hybrid Fragaria seed, and Fragaria berries thereof.

The present invention relates to plants propagatable from seed and seeds 
therefor. In particular, the invention relates to polyploid Fragaria or 
strawberry plants which are propagatable from seed. 
BACKGROUND 
Polyploid Fragaria plants do not breed true and the genetics is very 
complex. The progeny of a vegetatively propagated variety fertilised with 
its own pollen are all different. 
There have been some attempts to improve breeding strategies with a view to 
acquiring improved strawberry types however such strategies have met with 
limited or no success since problems associated with inbreeding depression 
have not been overcome. 
Niemirowicz-Szycytt K.[(1989) Acta Horticulturae 265: 97-104] failed to 
control inbreeding depression within the inbreeding program employed and 
as a result did not obtain viable and suitably homogeneous (uniform) 
inbred lines capable of being used in inbreeding programs for obtaining 
agronomically attractive strawberry plants in commercial numbers. 
Other workers have attempted to use alternative routes to obtain viable 
octoploid lines for use in strawberry breeding. Sayegh A. J. and Hernnarty 
M. J.[(1989) Acta Horticulturae 265: 129-135], attempted the production of 
haploids of commercial strawberry cultivars using androgenesis and 
intergeneric crosses followed by embryo rescue and culture. However, that 
approach was unsuccessful since the first essential step, that of 
obtaining haploids, was not realised and as a consequence the idea of 
doubling the haploid number to create octoploids and then selecting viable 
octoploid lines suitable for use in a breeding program could not be 
attempted. 
A recurring problem associated with strawberry breeding programs as 
disclosed in the art is that inbred lines obtained through repeated 
selfing programs lack plant vigour and as a consequence are too weak to 
continue with further. Lack of plant vigour is generally evident at about 
the third or fourth or later generations. 
In all cases, such programs have not been designed with a view to obtaining 
commercial quantities of F1 hybrids and seeds therefor. The goals of such 
breeding programs have been the acquisition of new breeding lines for use 
as basis for acquiring new varieties suitable for creating vegetatively 
propagated cultivars. 
As a consequence of the difficulties associated with classical strawberry 
breeding techniques, breeders have faced an uphill task in improving their 
gene pool and each year breeders search for seedlings from within their 
breeding programs for plants which display desirable characteristics. Such 
Fragaria seedlings are propagated vegetatively by runners or by 
micro-propagation techniques for as long as necessary, however, seed from 
such seedling plants cannot generally be used for propagative purposes 
since plants resulting from such seed generally do not display phenotypic 
similarity in terms of commercially desirable characteristics in plant 
habit (Guttridge C. G. & Simpson D. W. Grower, Dec. 23,(1982) pp 28-29). 
Plants grown from seed harvested from vegetatively propagated cultivars 
typically display marked differences in appearance or plant habit. Such 
differences render them commercially and agronomically unacceptable. 
Other disadvantages of supplying material grown via vegetative propagation 
and clonal propagation relate to the timing of release of such material to 
the grower. The propagator generally faces difficulties in timing and 
co-ordinating the release of sufficient numbers of strawberry plants to 
meet the requirements of the grower. 
A further disadvantage of vegetatively propagated material is that there is 
a high risk of disease transmission in such material and when disease 
infestation is found, the use of chemicals to combat any disease 
infestation may become necessary which in turn not only leads to increased 
costs but also to potentially undesirable environmental effects. It 
follows from the above that if uniform inheritance of commercially 
desirable characteristics could be achieved in cultivated strawberry 
plants propagatable from seed such an achievement would mark a significant 
departure from current commercial strawberry production practices with the 
inbuilt limitations as outlined above, and pave the way for a highly 
attractive means of producing large numbers of strawberries in an 
efficient and cost effective manner. 
Wild Fragaria species propagate from seed. However wild species generally 
produce small fruits and lack uniformity in appearance or plant habit. 
Recently, there have been attempts to develop cultivated strawberry plants 
propagatable from seed, however, such attempts have met with limited 
success from a commercial point of view. One attempt at a seed 
propagatable strawberry, described as being commercially available from 
Pan American Seed is described in product brochures as seed propagatable, 
however, this variety suffers from the fact that up to only 75% of the 
plants grown from seed are capable of flowering and beating fruit in their 
first season. The brochure does not disclose how said variety was 
obtained. Whilst a seed propagated strawberry which performed to such a 
specification may have satisfactory value to a gardener it would have 
dubious worth from an agronomical point of view for the commercial grower. 
High ploidy levels, such as octoploidy, in vegetatively propagated 
Fragaria, are generally associated with large berry size, while low ploidy 
levels such as diploidy are generally associated with smaller berry size. 
An example of a diploid species of strawberry, open pollinated F. vesca, 
is grown commercially from seed and is suitable for use in fruit drink, 
preserves production and the like, since the fruits which this species 
produces are small and not generally attractive for consumption fresh. The 
strawberry fruit production market is generally dominated by polyploid 
Fragaria species which are propagated via vegetative propagation. Such 
types include inter alia the octoploid species F. x ananassa. It would be 
highly desirable if polyploid Fragaria plants displaying commercially 
important characteristics could be propagated from seed reliably and 
without the need for vegetative propagation techniques. 
It results from the above that it is highly desirable to provide seed 
giving rise to polyploid Fragaria plants of which substantially each plant 
is capable of fruit productivity within its first year from sowing. The 
seeds should conveniently give rise to plants displaying similarity (i.e. 
substantial uniformity) in one or more commercially valuable traits and 
where desired display similarity in its overall plant habit. 
Despite such clear advantages of polyploid Fragaria plants that are 
propagatable by seed and of which substantially each plant is capable of 
fruit productivity, such plants/seed have not been provided for, the 
reasons being i.a. the complex genetics of the plants and the problems 
associated with the inbreeding depression typical for polyploid Fragaria 
plants. 
It has now surprisingly been found that it is possible to apply inbreeding 
techniques suitable for diploids, such as the use of sib or half-sib 
families in inbreeding selection steps, to polyploid Fragaria plants and 
that when crossing a polyploid Fragaria plant having one desired 
characteristic (or trait) with another polyploid Fragaria plant, such 
characteristic will be expressed in substantially all of its progeny (i.e. 
within the bounds of biological certainty, which is, in general in more 
than 95% of its progeny).

DETAILED DESCRIPTION 
According to the present invention there are provided cultivated polyploid 
Fragaria plants propagatable from seed wherein substantially each plant is 
capable of a fruit productivity within its first year. 
`Polyploid` means that the Fragaria plants are not diploid. They may 
display any ploidy level which may be found in the family Fragaria from 
triploidy through to octoploidy, nonaploidy, decaploidy or higher ploidy 
levels. Preferably, such Fragaria plants are octoploid. 
The term `plants` refers to whole plants and parts thereof, including seed, 
berries, plant tissue and cells thereof. 
The Fragaria plant may be selected from the group comprising F. x ananassa, 
F.chiloensis, F. virginiana, F. moschata and the like. A list of 
commercially important vegetatively propagated cultivars representative of 
various Fragaria species is provided in Fruit Varieties Journal 
42(3):102-108(1988) herein incorporated by reference, and the species so 
represented by the cultivan described therein are also included in the 
definition of Fragaria plants propagatable from seed of the invention. A 
preferred Fragaria species is that of F. x ananassa. Preferably, the F. x 
ananassa is octoploid. 
"Substantially each plant is capable of a fruit productivity in its first 
year" means that substantially each plant is capable of a fruit 
productivity in its first season after sowing or that the plant displays a 
fruit productivity within a particular season during its first year. 
Naturally, such a fruit productivity will be dependent on normal 
conditions required for pollination such as for example their being enough 
pollinating insects around in a particular season. 
`Substantially each plant` means more than 90%, particularly more than 95%, 
most preferably at least 99% of the plants. 
In addition to their capability to produce fruit within its first year from 
sowing, the plants of the invention preferably display similarity in one 
or more further commercially valuable traits. Typical examples of 
desirable commercially valuable traits are berry shape, berry size, fruit 
productivity, fruit taste, seed or achene coat permeability, daylength 
neutrality, number of runners per plant. A particularly preferred 
characteristic of the plants of the invention is daylength neutrality 
(i.e. that they can be grown year round, independent from the production 
area). The term daylength neutrality means that flower buds are inducible 
and yield fruit substantially independent of daylength, and irrespective 
of that be natural diurnal daylight, artificial light or a combination 
thereof. According to another particularly preferred characteristic the 
plants of the invention produce no or very few runners as compared to 
commercially available vegetatively propagated types. Typically, preferred 
plants of the invention will have less than 5 runners per plant. Plants 
which do not produce runners are especially preferred. Plants with a 
reduced number of runners produce more fruit per plant. 
The mature berries of plants of the invention for fresh consumption will 
preferably have an average diameter of at least 25 mm at its widest point. 
The plants of the invention most preferably display a general uniformity in 
appearance or similarity in plant habit, i.e. a similarity acceptable to 
the commercial strawberry grower. The plants may accordingly display 
tolerable differences in plant habit in the sense that such differences 
would not adversely influence the purchasing decision of customers to buy 
from the grower. For instance a difference in leaf shape in 5% of the 
plants may not constitute a commercially unacceptable difference whereas a 
difference in berry shape in the same percentage of plants could. 
Particularly perferred polyploid Fragaria plants according to the invention 
are in F1 hybrid form, they are preferably octoploids, more preferably 
octoploid F. x ananassa plants. The invention also provides parent lines 
of such F1 hybrid plants according to the invention and later generations 
derived from F1 hybrid plants according to the invention. 
For the purposes of the present invention a polyploid F1 hybrid plant is 
one which is a product of a cross between parent lines which show 
substantial uniformity in inheritance of desired characteristics after 
several generations of inbreeding. The term substantial uniformity in 
inheritance means more than 90%, particularly more than 95%, most 
preferably at least 99% of uniformity in inheritance. Typically, the 
choice in parent line involves inter alia an assessment on the combining 
ability of the selected parent lines. Such an assessment can be made when 
the parent lines display a predictable expression of a desired 
characteristic or a combination of desired characteristics. Such polyploid 
F1 hybrids display phenotypically homogeneous expression of commercially 
desirable characteristics. 
Such plants typically display similarity in plant habit to such an extent 
that the grower may be prepared to overlook those irregularities in plant 
habit which would not affect the commercial viability of the product. 
The invention also provides seeds giving rise to plants according to the 
invention and strawberry fruits or berries from plants according to the 
invention. 
Also encompassed within the ambit of the present invention are polyploid 
Fragaria plants which may be produced from seed of F1 hybrid Fragaria 
plants as described above. Seed of F1 hybrid Fragaria plants may give rise 
to progeny in the F2 or later generations which are seed propagatable and 
capable of producing fruit in their first season and in which the 
expression of desired characteristics of the F1 hybrid generation may be 
seen in such populations. The progeny, F2 and further generations of 
Fragaria plants derived from the F1 hybrid will show progressive 
segregation with respect to the expression of desired characteristics of 
the F1 hybrid, but may still fall within the scope of the invention. 
The fruits or berries of plants of the invention can be destined for any 
sort of consumption such as fresh eating as well as for processed forms of 
the fruit or berry such as in jams, confitures, fruit drinks, canned 
goods, liqueurs, cordials and the like. 
The polyploid Fragaria plants according to the invention am capable of 
being propagated from seed in commercial quantities. Advantages of 
producing seed for sale in commercial quantities for the large scale 
production of strawberry plants as opposed to providing plants which are 
vegetatively propagated are that seed generally gives rise to disease-free 
material, production costs may be reduced, and delivery and growing may be 
better planned. Where delivery to tropical countries is envisaged the 
provision of disease-free strawberry seeds would be particularly 
advantageous. 
In order to attain polyploid Fragaria plants and polyploid Fragaria F1 
hybrid plants of the invention a breeding protocol is established wherein 
inbreeding depression is controlled and wherein the object is to obtain F1 
hybrids, phenotypic uniformity in parent lines is maximised. 
The present invention accordingly provides a method of producing seed 
propagatable polyploid Fragaria plants wherein substantially each plant is 
capable of a fruit productivity within its first year which comprises 
selecting seedlings displaying the characteristic of interest from a 
population of seedlings and inbreeding such seedlings until the desired 
characteristic is stably inherited and capable of being reliably 
reproduced in each further generation. The number of inbreeding steps can 
be any number, however the number of steps generally involves about 4 
steps, and can involve between 4 and 10 steps or more. 
Preferably, the method of the invention makes use of full sib family or 
half-sib family selection steps. Such selection steps allow it to 
circumvent the problems involved with inbreeding depression typical for 
polyploid Fragaria plants as described in the art. 
The selection steps will conveniently involve selection for further traits 
of commercial value, e.g. one or more of the traits outlined above, 
particularly daylength neutrality and a low number (or absence) of 
runners. 
To increase the germination frequency of the seeds, it may be advantageous 
to employ a seed enhancement step in one or more of the selection steps. 
Thus obtained plants may be crossed to form hybrids. If the parent lines 
satisfy the criterion of similarity in plant habit required for commercial 
purposes, they may be employed as parent lines for the production of F1 
hybrid plants according to the invention. 
The production of the hybrid plants according to the invention typically 
involves the steps of 
i) crossing of parent lines; 
ii) harvesting the seeds of the said cross; 
iii) sowing the seeds; and 
iv) optionally employing a seed enhancement step at any suitable point 
prior to step iii). 
Fragaria seeds are true fruits or achenes which have impermeable, hard 
coats and depending on the permeability of the coat and/or seed dormancy, 
the seeds can take varying times to germinate. It is possible to select 
within the breeding program for plants giving rise to seeds having 
relatively more permeable seed coats and/or no seed dormancy and 
correspondingly fast germination times and therefore naturally high 
germination frequencies. 
Alternatively, seeds of plants utilised within the breeding program, as 
well as final product seeds may be subjected to a seed enhancement step at 
any suitable time. The seed enhancement step typically includes a 
treatment which weakens or increases the permeability of the seed coat 
without substantially interfering with the viability of the seed, either 
through physical means, e.g. scarification, or through chemical means, 
such as through the application of enzymes capable of acting on the seed 
coat, or through the application of mild bleaching agents (eg 1% solution 
of sodium hypochlorite for 15 minutes) and the like. The application of a 
seed enhancement step, if required, can improve the overall germination 
frequency of seed from Fragaria plants of interest to at least 85% 
depending on requirement. For example, for seeds from a Fragaria line 
selected for inter alia permeable seed coats (i.e. having a naturally high 
germination frequency) there may be no need to employ a seed enhancement 
step. However, in the case where the seed does not have a naturally high 
germination frequency, a seed enhancement step may be required. Thus in a 
preferment of the invention there are provided polyploid Fragaria plants 
of the invention which produce seeds having a germination frequency of at 
least 85%. 
Once the desired characteristic or characteristics are sufficiently stably 
integrated into the parent lines of interest they may then be crossed. The 
product of such a cross is regarded as an F1 hybrid in accordance with the 
definition provided herein. The F1 hybrids propagatable from seed display 
a stable plant habit from a commercial point of view as hereinbefore 
described. 
In a preferred embodiment of the invention the hybrids of the invention are 
obtained employing a male sterile parent line. 
Such male sterile parent line can be obtained by breeding a parent line 
employing the selection steps and optionally the seed enhancement step 
specified hereinabove and then crossing such parent line with a male 
sterility donor plant to obtain a male sterile plant and then backcrossing 
the said male sterile plant with the said parent line. 
In the case where the population of such plants is made up of a mixture of 
male sterile and male fertile plants there should also be a sufficient 
number of male fertile plants present such that pollination may proceed. 
Should the Fragaria plants be grown in a greenhouse and induced to flower 
or fruit in any season, for example winter, normal conditions for 
pollination may include any conventional pollinating procedures such as 
hand-pollination, the introduction of a colony of pollinating insects into 
the greenhouse and the like. 
The introduction of a back-crossing element into the breeding methods 
outlined above introduces the characteristic of male sterility into a 
parent line and reduces or eliminates the requirement to hand emasculate 
the fully fertile plants obtained in at least one of the parent lines used 
in the production of seed. The number of back crosses required can be any 
number, however it is generally found that at least three backcrosses may 
be required. The F1 hybrid plants resulting from sowing of the F1 seeds 
according to the invention are a mixture of fully fertile and male sterile 
plants since segregation with respect to male sterility occurs, however, 
in respect of the inheritance and expression of other desired 
characteristics the resultant plants conform with the description of 
commercial acceptability. 
There now follows a general description of how to obtain a polyploid F1 
hybrid Fragaria plant of the invention wherein the trait of male sterility 
is utilised in the breeding process. 
Strawberry plants propagated from runners are selfed to provide an F2 
population. These F2 populations display genotypic segregation. Plants 
displaying certain desired characteristics are selected in pairs from the 
F2 generation and crossed to provide an F3 generation, called a full 
sibling family (full sib family). The process of crossing full sib 
selections is repeated for subsequent generations until a sufficiently 
homogeneous parental line with respect to the expression of commercially 
desirable characteristics is able to be maintained. Members of such a full 
sib family parental line may then be cloned using conventional techniques 
such as tissue culture techniques or vegetative propagation techniques. 
Alternatively, such a full sib parental line may be permitted to set seed. 
In a variant on the above, use may be made of half-sib family selection 
lines. A half-sib family is one wherein selected plants of one line are 
pollinated with a pollen mixture obtained from these plants themselves or 
from plants of two or more further lines. The progeny (i.e. the seeds or 
plants) of a separate harvested plant is designated as a half-sib family. 
Thus, the female parent plant is known but the male parent plant is not. 
The half-sib lines may be treated in the same manner as the full sib lines 
with respect to selection and crossing until a sufficiently homogeneous 
parental line with respect to the expression of commercially desirable 
characteristics is able to be maintained. Members of such half-sib family 
parental lines may then be cloned using conventional techniques. 
Alternatively, the half-sib family parental line may be permitted to seed. 
Using either full sib family selection or half-sib family selection as 
described above, or other conventional breeding methods such as recurrent 
selection or mass selection, parental lines displaying commercially 
desirable characteristics may be treated as described hereinbelow. 
One parental line displaying commercially desirable characteristics may 
then be back-crossed several times with a male sterility donor plant in 
order to introduce male sterility into the said parental line. Once male 
sterility is introduced into this parental line by back-crossing it is 
crossed with a fully fertile parent line carrying a desirable 
characteristics. (In the alternative, and as alluded to above, the 
characteristic of male sterility can also be introduced into a parent line 
by simply selecting a plant displaying the characteristic of male 
sterility and introducing that characteristic into a prospective parent 
line utilising conventional procedures employed in breeding programs such 
as recurrent selection and mass selection). The product of such a cross is 
F1 hybrid seed which can give rise to F1 hybrid plants. 
According to a further preferred embodiment, the plants of the invention 
are cloned, employing conventional tissue culture techniques and growth 
medium. 
This cloning step facilitates large scale production of the plants 
(including plant parts, tissue, fruit and seed thereof) of the invention. 
The use of tissue culture techniques is particularly indicated for the mass 
production of one or both parent lines for hybrid production. 
Cloning here refers to the multiplication of tissue of plants according to 
the invention and subsequent multiplication of that to produce large 
numbers of plants with the same genotype. Cloned plants may be crossed 
either with plants obtained through conventional inbreeding and crossing 
techniques or with other suitably cloned plants. In a preferment, cloned 
parent plants may be crossed with other cloned parent plants and the seeds 
of such crosses harvested. Alternatively, tissue capable of being cloned 
in tissue culture may be taken from plants of the invention and used to 
clone such plants per se. Such tissue derived material may be grown to 
seedling stage and sold to growers in commercial quantities. `Tissue` may 
refer to individual cells, organs of plants such as roots, shoots, leaves 
or pieces of organs, seedlings and the like. 
F1 hybrid seeds M8 (Example 2 hereinafter) and M55 (Example 1 herinafter) 
have been deposited 9th Nov. 1992 with the NCIMB, Aberdeen and allocated 
deposit numbers NCIMB 40527 and NCIMB 40528 respectively. 
The invention will now be further described with reference to the following 
examples. It is to be understood that the examples are not intended to 
limit the scope of the invention in any way. 
EXAMPLE 1 
Production of F1 hybrid octoploid Fragaria plant displaying reduced numbers 
of runners, and fruit production per plant utilising two day neutral 
lines. 
Reference is made to FIG. 1 hereinafter. 
A vegetatively propagated octoploid Fragaria variety, cv Ostara (CPRO, 
Wageningen), displaying inter alia day neutrality and soft fruit is 
selected and seed is harvested therefrom. The seed gives an F2 population 
designated with the in-house number, E 21 OP (where OP stands for open 
pollinated). A plant is selected from the F2 population (E21-6) open 
pollinated and seed harvested therefrom. The seed gives an F3 population, 
designated F17. A plant is selected from this F3 population and designated 
F 17-2, open pollinated and seed harvested therefrom. The seed gives an F4 
population designated G 44. A plant is selected from this F4 population 
and designated G 44-1. G 44-1 is self pollinated (S) and seeds harvested 
therefrom. Seeds of G 44-1 are sown and seedlings designated H 67. Two 
plants designated H 67-3 and H 67-1 m selected, self pollinated 
respectively and seeds are harvested therefrom. Seeds from H 67-3 S and H 
67-1 S are sown separately (i.e. without mixing the two seed populations) 
and populations of seedlings obtained designated I 167 and I 165. Plants 
(I 167-1 and I 165-6) from the two sister lines are crossed to restore 
plant vigour. Seeds harvested from this cross are sown and are given the 
field designation K 148. Half-sibs are created by taking five female 
parent plants from K 148 and pollinating them with a mixture of pollen 
from the same five parent plants thereby creating a subpopulation of K 
148. Plants are harvested separately from K 148. Out of the half-sibling 
population the progeny of one of the selected plants (K 148-2) is 
designated L 107, and a plant is selected from this population and given 
designation L 107-1. This plant is the male parent plant i.e. the F8 
inbred generation from cv Ostara. These plants display inter alia day 
neutrality and reduced numbers of runners. 
Female parent lines are created from seeds harvested from a vegetatively 
propagated octoploid Fragaria variety, cv Brighton (University of 
California), in the open field and plants derived therefrom are designated 
I 63 OP (F2). Half-sib families of I 63 are created using a similar 
procedure to that used in obtaining the male parent line. Mixing of seeds 
of the half-sib families is avoided. The half-sib families are sown and 
one of them designated K 249. Half-sib families of K 249 are created using 
a similar procedure to that described in obtaining the male parent line 
above. Mixing of seeds of the half-sib families is avoided. The half-sib 
families are sown and the progeny of one of the selected plants (K 249-1) 
is designated L 203. A plant is selected from this L 203 population and 
designated L 203-2. This plant is the female parent plant (i.e. the F4 
inbred generation from cultivar Brighton) and displays the characteristics 
inter alia of medium day neutrality, reduced numbers of runners, and fruit 
productivity per plant within its first year. 
The two parent lines are crossed to create F1 hybrid plants which are 
designated M 55. These octoploid Fragaria plants display homogeneous fruit 
production, fruit size and shape, reduced numbers of runners, day 
neutrality, and a fruit productivity within their first year. 
EXAMPLE 2 
Production of an F1 hybrid octoploid Fragaria plant displaying fruit 
production in its first year utilising a day neutral line and a short day 
line. 
Reference is made to FIG. 2 hereinafter. 
Seeds from cv Douglas (University of California) a short day vegetatively 
propagated octoploid Fragaria variety, are sown to provide a population 
designated G 153 OP (F2). A plant is selected from this population and 
designated G 153-41, open pollinated, and the seed harvested therefrom and 
sown to provide a population designated H 294. A plant is selected from 
this population and designated H 294-6, open pollinated, and the seed 
harvested therefrom and sown under designated number I 371. Out of I 371, 
half-sib families are created using procedures as outlined in example 1. 
One of these half-sib families (I 371-3) is sown under designation K 426. 
Out of K 426 four plants are selected and the pollen of these plants is 
mixed for crossing with I 109-1 to test for combining ability. Combining 
ability is assessed via observing the inheritance of characteristics of a 
line in combination with other lines. 
Seeds from a vegetatively propagated, day neutral octoploid Fragaria 
variety Rapella (CPRO, Wageningen) are sown and given the designated 
population number G 17 OP. A plant is selected from this population and 
designated G 17-1 and self pollinated. The seeds of G 17-1 are sown, grown 
and the resultant population designated H 42. A plant from this population 
is selected and given the designation H 42-4 and self pollinated. The 
seeds of H 42-4 are sown, grown, and the resulting population given the 
designation I 109. A plant is selected from this population and designated 
I 109-1. This plant is a female parent plant which displays inter alia day 
neutrality. 
I 109-1 and pollen from the four plants from K 426 are crossed. This 
results in the octoploid Fragaria F1 hybrid plant M 8. These plants 
display inter alia uniform vigorous plant habit, high fruit yield, and 
fruit production per plant in their first year. 
EXAMPLE 3 
Production of an F1 hybrid octoploid Fragaria plant displaying fruit 
production in all plants demonstrating the use of the trait of male 
sterility in the breeding scheme. 
Reference is made to FIG. 3 hereinafter. 
Seeds from a short day vegetatively propagated octoploid Fragaria variety, 
cv Honeoye (Cornell University, Geneva Expt. Station, NY State) are sown 
and the population of seedlings given the designation I 461 OP. A plant is 
selected from this population, I 461-1, and seeds produced via open 
pollination are then sown. From the population of seedlings, K 484, a 
plant is selected (K484-1), open pollinated and seeds therefrom are sown, 
producing population, L 396. Two plants (L396-2 and L 396-4) are selected 
to provide a pollen mixture which is used to fertilise the female parent 
plant, L 29-1 ms. 
Seeds from a male sterile source, an octoploid experimental Fragaria plant 
displaying male sterility, are designated G 1. (Seeds from any Fragaria 
plant displaying the characteristic of male sterility may be selected as a 
male sterility source. An example of a commercially available variety 
which may be used as a male sterile source is cv Pandora, East Mailing 
Experimental Research Station). G 1 seeds are sown, grown, and a plant 
displaying male sterility is selected, G 1-1 ms. Seeds are produced via 
open pollination and harvested from G 1-1 ms and sown providing a plant 
population designated H 27 OP. A plant displaying male sterility is 
selected from this population, (H 27-1 ms ), and is crossed with a pollen 
mixture from a group (H 42) of ten (10) plants selected from an F3 Rapella 
day neutral variety population created via general selection procedures 
such as those employed for other lines as described above (e.g. F4 plant I 
109-1, FIG. 2), providing a population of plants (K 83) from which K 83-2 
ms is selected and backcrossed with K 199-6 an F5 Rapella plant. From the 
resulting population, designated L 29 a plant displaying male sterility is 
selected (L 29-1 ms ) and crossed using pollen of the plants L 396-2 and L 
396-4 which results in an F1 hybrid, M 215. All plants of this F1 
octoploid hybrid display a fruit productivity and segregate 50%:50% with 
respect to male sterility. 
EXAMPLE 4 
Production of F1 hybrid octoploid Fragaria plants displaying uniformity in 
plant characteristics and segregating 50%/50% with respect to male 
sterility utilising short day (SD) and day length neutral (DN) lines. 
Reference is made to FIGS. 2, 3 and 4 hereinafter. 
Seeds from a short day (SD) vegetatively propagated octoploid Fragaria 
variety, cv Kent (Agricultural Research station, Kentville, Nova Scotia, 
Canada) are sown and the population of seedlings (F2 population) given the 
designation I 460 OP (where OP stands for open pollinated). A plant is 
selected from this population, 1 460-2, and seeds produced via open 
pollination are then sown. From the population of seedlings, K 483, a 
plant is selected (K 483-2), open pollinated and seeds therefrom are sown, 
producing population L 394. Two plants, L 394-2 and L 394-3, are selected 
from the L 394 population and crossed to provide a full sib family 
designated M 353. F5 Plant, M 353-3, is selected as the male parent of the 
F1 hybrid R 199. 
Seeds from a male sterile some, an experimental octoploid Fragaria plant 
displaying male sterility, are designated G 1. (Seeds from any Fragaria 
plant displaying the characteristic of male sterility may be selected as a 
male sterility some. An example of a commercially available variety which 
may be used as a male sterile source is cv Pandora, East Malling 
Experimental Research Station). G 1 seeds are sown and a plant displaying 
male sterility is selected (G 1-1 ms). Seeds are produced via open 
pollination and harvested from G 1-1 ms and sown. The resultant population 
of plants is designated H 27 OP. A plant displaying male sterility is 
selected from this population, (H 27-1 ms) and is crossed with a pollen 
mixture from a group (H 42) of ten (10) plants selected from an F3 Rapella 
day neutral variety population created via general selection procedures 
such as those employed for other lines as described above (e.g. F4 plant I 
109-1, Breeding Scheme 2), providing a population of plants (K 83) from 
which K 83-2 ms is selected and backcrossed with K 199-6 an F5 Rapella 
plant. The population resulting from this first backcross is designated L 
29. Out of L 29, a male sterile plant L 29-1 ms is selected and 
backcrossed with an L 175-1 plant from an F6 Rapella population (L 175). 
The result of this backcross is designated M 58. Out of this M 58 
population a male sterile plant is selected, M 58-1 ms, and backcrossed to 
M 111-1, an F7 plant selected out of an F7 Rapella population. The 
population resulting from this backcross is designated M 501. Out of the M 
501 population a male sterile plant is selected, M 501-1 ms, and 
backcrossed with an M 111-1 plant yielding a male sterile population, P 
205, from which a male sterile plant is selected for crossing with M 
353-3. P 205-1 ms is the fourth backcross to Rapella. 
Plants P 205-1 ms and M 353-3 are crossed, resulting in octoploid F1 hybrid 
R 199 displaying phenotypical uniformity at least with respect to fruit 
productivity in its first year, day neutrality, and 50%:50% segregation 
for male sterility. 
EXAMPLE 5 
Effect of Seed Enhancement Treatment on octoploid Fragaria x ananassa F1 
hybrid seed 
3.times.1 lots of 6 gms of octoploid Fragaria x ananassa F1 hybrid seed 
(inhouse designations K1, K2, and K3) are placed in 300 mls of a 7% by 
volume solution of sodium hypochlorite at an initial temperature of 
20.degree. C., for time intervals of 15, 30, and 45 minutes. Controls are 
placed in 300 mls of water at 20.degree. C. over the same time intervals; 
all other experimental parameters being the same as for test samples. The 
temperature of the test samples starts at 20.degree. C. rising to 
23.degree. C. during the test. After each time interval the seeds are 
removed from the solution, placed in a nylon mesh bag and washed in 10 
liters of water for 1 minute. The washing procedure is repeated a further 
two times. After washing the seeds are centrifuged for 1 minute at 1000g. 
Seeds are further dried in an airstream (about 40 m/minute) for a period 
of up to 24 hours. Germination is tested on samples of 200 seeds from each 
seed lot by sowing treated seeds and controls on top of paper in the light 
at 25.degree. C. and germination monitored daily for 28 days by counting 
the number of protruding radicles. Total germination is determined at 28 
days. 50% total germination (T.sub.50) and spread is determined following 
the method as outlined by Orchard T. J. (1977) Seed Sci. & Technol., 5, 
61-69. 
Results are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Treatment T50 Spread 
% Germ 
% Germ 
(Sodium chlorite) (Days) 
Day 14 Day 28 
__________________________________________________________________________ 
Seedlot 1 
Control (water) 
12.0 
4.8 59 88 
(K1) hypo 7% 15 min 
10.5 
3.4 82 97 
hypo 7% 30 min 
7.2 
2.8 97 100 
hypo 7% 45 min 
6.6 
2.1 98 99 
Seedlot 2 
Control (water) 
13.2 
5.1 58 94 
(K2) hypo 7% 15 min 
10.6 
5.4 81 99 
hypo 7% 30 nun 
8.1 
3.3 91 97 
hypo 7% 45 min 
-- -- -- -- 
Seedlot 3 
Control (water) 
12.2 
5.2 67 98 
(K3) hypo 7% 15 min 
10.4 
3.8 82 98 
hypo 7% 30 min 
7.1 
2.2 97 98 
hypo 7% 45 min 
7.1 
2.2 100 100 
__________________________________________________________________________ 
1) k87.1 .times. k407.1 F1 hybrid K1 
2) k87.1 .times. k407.1 F1 hybrid K2 
3) k148.2 .times. k407.1 F1 hybrid K3 
-- not done 
EXAMPLE 6 
Cloning of octoploid Fragaria plants utilising Tissue Culture techniques 
Explant material comprising stem material containing meristem material is 
cut from runner tips of K 148-2 and surface sterilised by firstly dipping 
(no more than 5 secs) in a 70% solution of ethanol. The material is then 
placed in a 1.5% by volume solution of sodium hypochlorite (30 ml) 
(Glorix, Fenix BV Zwolle, NL) and surface sterilised for 15 minutes on a 
rotary shaker set at 200 rpm at room temperature. The explant material is 
then rinsed in 3 volumes (3.times.30 ml) of sterile physiological salt 
solution (8.5 g/l) and meristem tissue excised from the stem thereafter. 
Metistem tissue is placed in culture tubes (2 cm diameter) containing 16.7 
ml initiation culture medium per tube. The initiation medium contains: 
macro-elements as described by Knop W [(1865) Landw. Vers. Stn. 7: 93-107] 
supplemented with: 
10 mg/l FeSO.sub.4.7 H.sub.2 O and 
10 mg/l Na.sub.2 EDTA micro-elements and organic elements as described by 
Murashige T. & Skoog F [(1962) Physiol. Plant. 15:473-497] 
1.2 mg/l KIBA (Indole-3-butyric acid- Sigma) 
0.1 mg/l BA (N.sup.6 -Benzyl adeninc (Fluka AG) 
44 g/l glucose monohydrate 
7 g/l agar (Lab M) (Amersham, UK) 
pH 5.6 
31 meristems are placed in the dark for 7 days then transferred to light 
conditions of (16 hrs light 3000 lux/8 hrs dark). Temperature is 
maintained in the range of from 22.degree.-24.degree. C. After 6 weeks 
shoots formed are placed in glass jars having lids with interrupted inner 
rims (to allow gaseous exchange to take place), on 62.5 ml multiplication 
medium comprising the same elements as the initiation medium except for 
plant hormone concentration being KIBA 1.2 mg/l and BA 1.0 mg/l. 
Temperature and light conditions are the same as for the initiating 
cultures; multiplication period of 7 weeks. At the end of the 
multiplication period 150 shoots are collected and transferred to roofing 
medium. (In order to obtain more shoots for rooting from the 
multiplication step shoots may can be sliced into more pieces depending on 
how many plants are required, and then placed on multiplication medium). 
The rooting medium is similar to the multiplication medium except that BA 
is excluded from it. The rooting period is 6 weeks; all other parameters 
are the same as for the multiplication step. After the rooting period, 
rooted shoots are rinsed carefully in luke warm water and transferred to 
potting soil 3 (commercially available from Jongkind Grond BV Aalsmeer, 
NL) and permitted to grow into plantlets under glass jars at a high 
relative humidity (95%). Hardening of the plantlets is effected by gradual 
reduction of the relative humidity to about (70) over a period of 2 weeks. 
Plantlets are then transferred to the greenhouse. 
Plantlets of K 148-2 are of good quality and display a survival rate of 99% 
in the greenhouse