New interspecific hybrids of Fuchsia species L. (Onagraceae)

International Journal of Agriculture and Crop Sciences. Vol., 1 (1), 1-8, 2009
Available online at http://www.ijagcs.com
©2009 IJACS Journal
New interspecific hybrids of Fuchsia species L. (Onagraceae)
RAMA S. TALLURI
School of Biological Sciences, the University of Auckland, Private Bag 92019,
Auckland Mail Centre, Auckland 1142, New Zealand.
Corresponding author Email: ramatalluri566@gmail.com
ABSTRACT: An extensive hybridization programme between American species and between them and
New Zealand one resulted in the production of new hybrids in Fuchsia. A significant first has been the
production of yellow flowered hybrid from a cross between F. encliandra and F. procumbens. It combines
the plant growth character of F. encliandra and the flower colour of F. procumbens. The procumbent plant
growth character has also been transferred in a cross with F. splendens. Many other interesting hybrids
have also been produced with interesting variation in floral and vegetative characters. Not all attempted
cross combinations were successful in this study and a variety of pre- and post fertilization barriers to
hybridization were observed. Once hybrids were produced in the crosses between American species, most
of the plants were vigorous unlike most of hybrids produced between New Zealand and American species.
An exception amongst the crosses between American species produced sub-viable plants that showed a
virus-like syndrome. Overall, this study has shown that in Fuchsia crossability is not necessarily related to
chromosome number, ploidy level, taxonomic position, and genome size.
Key words: Fuchsia; hybridization; morphology; taxonomic position; genome size
INTORDUCTION
Fuchsia is a large and distinctive
genus in the family Onagraceae comprising
over 110 species, classified into 12 sections.
The tropical Andes, Mexico-Central America,
Hispaniola, southeastern Brazil, southern Andes
and South Pacific region (New Zealand and
Tahiti) are the biodiversity hotspots for this
genus. It is also an important floricultural genus
of trees and shrubs.
Interspecific hybridization appears to
be relatively common in nature where pairs
of Fuchsia species are sympatric (Berry, 1982,
1989; Godley and Berry, 1995; Hoshino and
Berry, 1989). This occurs despite the observations
that the majority of species are self-fertile
(Berry, 1982 & 1989) which suggests that the
species involved in the formation of hybrids are
probably out crossing.
Inter-sectional hybrids between
American Fuchsia species have been reported
previously and the present-day Fuchsia cultivars
are mostly shrubs with flower colours that range
from red through purple to pink and white. They
include hybrids between F. cordifolia (sect.
Ellobium) x F.globosa (sect. Quelusia)
developed by Paxton, 1843; F. fulgens (sect.
Ellobium) x F. globosa (sect. Quelusia)
developed by Lindey, 1840; F. magellanica
(sect. Quelusia) x F. fulgens (sect. Ellobium)
developed by Siebert & Voss, 1896, Munz,
1943, Bailey, 1900, Chaudhuri, 1956. The
hybrid between American and New Zealand
Fuchsia species was F. splendens (sect.
Ellobium) x F. procumbens (sect.
Procumbentes) developed by Wright, 1983 (cited
in Goulding, 1995).
The novel characters of the New
Zealand species, F. procumbens, in particular its
erect flowers that lack petals but have yellow and
purple sepals and a procumbent growth habit,
have the potential to enhance the range of
fuchsia cultivars, characters that are absent
from existing cultivars. Thus one major aim of
the present study was to determine whether this
species could be hybridized with its South
American relatives.
MATERIALS AND METHODS
Plant material
Fifteen species and three cultivars
belonging to seven sections of the genus were
used for experimental hybridization (Table 1).
Plants were grown in a glasshouse at the
University of Auckland, New Zealand. The
majority of the species used in the present study
were diploids (2n=22) with only 4 tetraploids
(F. boliviana, F. glazioviana, F. hatschbachii

Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
and F. magellanica (2n=44)). In the cultivars,
chromosome number varied from 2n=33 in
Table 1. Species and cultivars of Fuchsia used in this study
"Gartenmeister Bonstedt", 2n=44 in "Timothy
Hammett" and 2n=99 in "Dr. Hammett".
S.No Species/Cultivars Chromosome number 2n= Section
F. arborescens Sims. 22
2. F. boliviana Carr. 44 Fuchsia
3. F. encliandra Steud. 22 Encliandra
4. F. excorticata Linn. 22 Skinnera
5. F. fulgens Carr. 22 Ellobium
6. F. glazioviana Tamb. 44 Quelusia
7. F. hatschbachii Sekcja. 44 Quelusia
8. F. magellanica Lam. 44 Quelusia
9. F. microphylla Kunth. 22 Encliandra
10. F. minutiflora Hemsl. 22 Encliandra
11. F. procumbens Cunn. 22 Procumbentes
12. F. reflexa 22 Encliandra
13. F. splendens Zucc. 22 Ellobium
14. F. triphylla Linn. 22 Fuchsia
15. F. trumpetor 22 Fuchsia
16. “Dr. Hammett 99 cultivar
17. “Gartenmeister Bonstedt” 33 cultivar
18. “Timothy Hammett” 44 cultivar
Hybridization
A minimum of five flowers of each
species was emasculated one day before anthesis
during the flowering season. However, the
number of crosses performed with each species
or cultivar was determined by the synchrony of
flowering and the number of flowers available at
the time of crossing programme. Fresh pollen
was dusted on to the stigma two days after
emasculation and a sample of the emasculated
flowers was routinely left un-pollinated as
controls to estimate the level of accidental selfpollination.
Fruits were harvested when matured
and any seed was collected, counted to produce
F1 generation.
Morphology of species, cultivars and hybrids
The morphology of species and
hybrids was examined using the Horticultural
colour chart, issued by the British Colour
Council in collaboration with the Royal
Horticultural Society (Wilson, 1942) to study
the heritability of the characters from the
parents and these plants were grown in a
glass house.
RESULTS
One hundred and twenty five cross
combinations were attempted (including hybrid
crosses with F. procumbens and other back
crosses) and of these a total of 43 combinations
produced fruit. Of these 16 cross combinations
produced viable F1 plants which, with the
exception of the cross between F. splendens and
F. procumbens, grew to maturity and flowered.
The percentage fruit set from these successful
crosses was highly variable and ranged from
100% to 0% (Table 2).
The hybrids that were produced could
be placed into a number of different categories.
Many of the hybrids were reasonably uniform
and intermediate between the parents for
many/most characters but in several
combinations this was not the case, with
unexpected phenotypes and variation between F1
siblings.
Crosses using F. procumbens as the
female parent were less successful than the
reciprocal. Only two of the cross combinations,
F. procumbens x F. fulgens and F. procumbens x
F. hatschbachii set fruit (Table 2) and the seeds
from the cross between F. procumbens x F.
fulgens did not germinate. Although the seeds of
F. procumbens x F. hatschbachii germinated,
seedlings were not vigorous and died within two
months of germination. Crosses between F.
procumbens as male and two Central American
species (F. encliandra and F. splendens)
produced viable progeny. The hybrid F.
encliandra x F. procumbens was not vigorous
though it did produce interesting yellow/pink
flowers but no progeny were raised from this
plant as it died shortly after flowering. The other
hybrid F. splendens x F. procumbens has not
flowered and remains in a vegetative state.
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Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
Table 2. The results of experimental hybridizations in Fuchsia species and hybrids. The numbers in each column are
the number of crosses made/ the percentage of the crosses that set fruit.
Many of the hybrids produced when F.
glazioviana, F. magellanica and F. hatschbachii
were used as one of the parents showed a
reversion to the red and purple wild type Fuchsia
flower colour. In several combinations, for
example, F. triphylla x F. arborescens and F.
triphylla x F. Boliviana, staminodes were
produced. Another set of hybrids did not show
intermediate phenotypes. They included F.
fulgens x F. magellanica, F. triphylla x F.
boliviana and F. triphylla x F. arborescens.
Morphology of interspecific hybrids between
South American and New Zealand species
F. encliandra x F. procumbens:
This hybrid showed an interesting
combination of characters of the two parental
species, resembled F. encliandra in plant
growth character and F. procumbens in flower
colour and shape. The plants were not vigorous
(short lived) and the leaves resembled one of
its maternal parents i.e., F. encliandra. The
flowers were upright, yellow when young but
turning to pink at maturity. The immature
flowers corolla tube was cypress green at the
bottom and had Indian yellow coloured sepals
with fuchsine pink to a mix of mallow purple
& magenta tips. In mature flowers, corolla tube
had a mix of rose bengal and crimson colour
and apetalous. There were eight stamens with
crimson coloured filament and anthers. The
style had a mixture of rose bengal and crimson
colour and stigma colour was sulphur yellow,
which changed to crimson colour when it
matured (Fig 1 (A-D) and Fig 2)
Figure 1. Floral morphology of yellow hybrid fuchsia and parental species
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Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
Figure 2 Yellow hybrid Fuchsia (F1 hybrid: F. encliandra F. procumbens)
F. splendens x F. procumbens: This
hybrid resembled F. procumbens in its growth
form having a trailing habit. The leaves were
intermediate in size and shape between the two
parental species. The plants were deciduous,
DISCUSSION
In an attempt to produce novel
hybrids between the American and New
Zealand species of Fuchsia, an extensive
Figure 3. F1 hybrid: F. splendens F. procumbens
vigorous, but did not flower even after three
years from the date of transplantation (Fig 3 A-
C).
hybridization programme was carried out which
has resulted in a fairly large number of new
hybrids. Many new hybrids have been
produced in a genus where there are few
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Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
published reports of successful hybrid
production.
Most of the present day cultivars and
American species of Fuchsia are trees or shrubs
with red or purple flowers. Fuchsia
procumbens, a native New Zealand (endemic)
species is unique in having upright yellow flowers,
unusual blue pollen and a procumbent plant
growth habit. The previous hybridization
programmes carried out all around the world to
get a yellow hybrid in Fuchsia have been
unsuccessful. As a result of the present
hybridization programme the yellow flower
colour of F. procumbens has been successfully
transferred into a hybrid in a cross with F.
encliandra. This novel hybrid is the world’s
first yellow-flowered fuchsia hybrid with the
plant growth character of F. encliandra and the
flower colour and shape of F. procumbens.
The yellow flower colour changes to rose
madder as it matures. Unfortunately, this hybrid
combination was not particularly vigorous and
therefore one next step in the hybridization
programme will require testing a range of
F.procumbens and F. encliandra genotypes to
see whether more vigorous hybrids can be
produced. A number of other interesting
hybrids were produced in this study including
a hybrid having a trailing plant growth habit (F.
splendens x F. procumbens) and hybrids with
staminode flowers (F. triphylla x F.
arborescens and F. triphylla x F. boliviana).
Other hybrids had profuse flowering over an
extended period and are best suited as potted
plants or for hanging baskets. These include F.
triphylla x F. arborescens and F. fulgens x F.
magellanica. The male sterility that arises as a
consequence of the stamens being modified as
petals, as in the hybrid between F. triphylla and
F. boliviana, has potential in commercial
horticulture due to the fact that the male sterile
flowers remain longer on the plant.
In addition to these floral features, the
pigmentation in the leaves, stems or other
vegetative parts may also have value in
ornamental horticulture. There were many
hybrids produced in this study that inherited
this feature from the parental species. For
example, the dark pigmentation of F.
glazioviana and F. magellanica has been
inherited by their hybrids when they were
crossed with F. boliviana, F. triphylla and
“Timothy Hammett”. Dark coloured plants were
also produced from the hybridization between F.
glazioviana and F. magellanica.
One other interesting feature was that the
success of hybridization with F. procumbens
was greater when used as the male parent than
as the female parent. This confirms the fact
that most of the hermaphrodites function as
males rather than as females (Arroyo a n d
Raven, 1975; Lloyd, 1973; Young, 1972;
Godley, 1963 & 1957).
Crossability in relation to taxonomic position
The evolutionary or taxonomic
relationship between species and their
crossability is not always straightforward, as it
is complex in nature. It is also important to
note that survival of the hybrid progeny is a
more realistic measure of relationship and
should be the main criterion rather than fruit
set alone to assess the success of a cross (Duvall
and Biesboer, 1988). The hybrids produced in
this study were compared by evaluating each
of them with the taxonomic position of
parental species (Table 1 & 2). There does not
appear to be any relationship between
crossability and taxonomic position of the
parental species and species crossing
boundaries are difficult to define. In instances,
where the parental species occur in the same
geographic area, the present evidence from
interspecific hybridizations indicated that these
species are often not genetically isolated
despite the fact that they are morphologically
quite distinct.
In addition, the more distantly related
sections cross as readily as the more closely
related ones. Firstly, the hybrids produced
between the species of the same section were
sect. Ellobium (F. fulgens x F. splendens),
sect. Quelusia (F. glazioviana x F.
magellanica), and sect. Fuchsia (F. triphylla
and F. boliviana) represent a combination
between closely related species. Secondly,
intersectional hybrids were also produced in
the present study. Some of the hybrids
produced between sects. Fuchsia and Quelusia)
were: F. boliviana x F. glazioviana, F.
boliviana x F. magellanica and F. triphylla x
F. glazioviana. A reciprocal intersectional
combination between F. hatschbachii and F.
boliviana was also produced. Results from
Fuchsia (Godley and Berry 1995, Berry 1989),
Cyphomandra (Bohs, 1991) and Betula
(Erikkson and Jonsson, 1986) where species can
hybridize regardless of their taxonomic position
tend to suggest that sectional classification does
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Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
not correlate with crossability of the species. To
cite a few more examples, in Rhododendron,
section Vireya and most other sections of the
genus with the exception of certain species in
subsection Pseudovirea, the species were highly
cross-compatible and many interspecific hybrids
of horticultural value have been produced
(Williams a n d Rouse, 1988). Another
example is the South American Solanum
species (tuber bearing section Tuberarium) that
are quite diverse and from different series, but
showed a high degree of cross compatibility
(Summers and Grun, 1981). On contrast, inviable
hybrids from the interspecific hybridization
between Oryza breviligulata and O. glaberrima
were reported by Chu & Oka, 1970, despite the
fact that they are closely related.
Initial studies in Eucalyptus appeared
to show that hybridization was more successful
when the parents were closely related (Pryor
and Johnson, 1971) but later studies, where
more combinations were made, tend to show
that this is not really the case (Pryor, 1976). For
example, intersectional crosses: E. nitens with
E. grandis or E. camaldulensis; E. ovata, and
E. rodwayi indicated that these species could
cross with distant species, unlike previous
reports. Interspecific combinations: E. nitens
with E. dalrympleana, E. gunnii, E. globulus,
E. cordata, E. johnstonii, E. morrisbyi, E.
viminalis, E. ovata, E. rodwayi were also
successful except with E. urnigera. Other
interspecific hybrids obtained in the study
conducted by Tibbits, 1989 with the overall
objective of producing hybrids that are fast
growing, frost resistant with good wood
qualities suitable for pulp industry in Eucalyptus
were amongst E. gunii, E. regnans, and E.
globulus. This proves the difficulty in
explaining the relationship between the
crossability in relation to taxonomic position of
the species and an extensive hybridization
programme needs to be under taken before
discussing about the crossability of different
species in any genus.
Despite their morphological differences
and vast geographical separation two viable
hybrids were produced between F. procumbens
and two Mexico-Central American species (F.
encliandra and F. splendens). Of these two, the
hybrid F. encliandra x F. procumbens reached
to flowering stage although it was less vigorous
and had a unique combination of the parental
characters. The other hybrid has not flowered
even after nearly three years from the date of
its sowing but it is vigorous and has the
procumbent growth form of F. procumbens.
Not withstanding its limitations, this study does
suggest the possibility of the transfer of the
unique characters of F. procumbens into some
American species. Greater success may be
achieved if the barriers associated with
hybridization can be overcome by using
techniques such as induced polyploidy and
embryo rescue or by trying a range of F.
procumbens and F. encliandra genotypes to get
commercially viable hybrids. Further,
h y b r i d i z a t i o n between F . splendens and
F. procumbens has been reported previously by
Wright, 1983, but there is no description of
this hybrid in the scientific literature (cited
in Goulding, 1995). This study also shows that
physiological isolating mechanisms are in
operation in Fuchsia and are additional to the
geographical isolation of species.
Several suggestions can be made to
help explain the results obtained in the
interspecific hybridization in Fuchsia. Firstly, it
is possible that despite the placement of the
American species into a number of sections, the
species of the sections are fairly similar and
can relatively easily produce interspecific
hybrids. On the other hand, the geographically
disjunct New Zealand Fuchsia could not cross
successfully with most South-Central American
species, suggesting a more distant genetic
relationship.
The results of the hybridization
programme coupled with reports of natural
hybrids (Berry, 1982, 1985 & 1989; Godley and
Berry, 1995; Hoshino and Berry, 1989) suggest
that hybridization among Fuchsia species is not
uncommon and that ecological factors are
probably important in maintaining integrity
when species occur in sympatry.
The male sterility that was observed in
the hybrid between F. triphylla and F. boliviana
that is a consequence of the conversion of
stamens into petals may have some commercial
potential as these male sterile flowers are very
long-lived.
Overall, a significant number of new
hybrid combinations have been produced from
this hybridization programme though many
crosses between species either failed to set seed
or produced progeny of limited vitality. The
success of crosses does not appear to be strictly
linked to the most recent taxonomic system that
divides the genus into a number of sections
(Berry et al., 2004). The geographically isolated
New Zealand F. procumbens did not cross with
most of the South-Central American species,
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Intl J Agri Crop Sci. Vol., 1 (1), 1-8, 2009
suggesting a more distant genetic as well as
geographic relationship.
Notwithstanding its limitations, this
study does suggest the possibility of the transfer
of the unique characters of F. procumbens into
some American species and crossability is not
related to chromosome number, ploidy level,
taxonomic position (Table 1 &2). Crossability of
these species was also compared with the
published data on genome size (Talluri and
Murray, 2009) indicating no obvious
relationship.
ACKNOWLEDGEMENTS
This work forms the part of PhD thesis
submitted to the University of Auckland, New
Zealand. The support of Dr. B.G.Murray, SBS,
the University of Auckland; the Foundation for
Research, Science and Technology and Dr. Keith
Hammett, Hammett Plant Breeding Ltd.,
Auckland, New Zealand for the supply of
unrooted cuttings of Fuchsia species and
cultivars used in this study is gratefully
acknowledged.
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