Cytotaxonomic
studies
in
the
Symphytum.
Crossing experiments
officinale
L.
Th.W.J. Gadella
Botanisch Museum
en
genus
II.
between Symphytum
and Symphytum
asperum Lepech.
and E. Kliphuis
Herbarium,
Utrecht
SUMMARY
Crossing experiments
2n=48)
of
morphologicallyclosely
that
hybrids
could
crossed with
The
1.
were
carried
Symphytum officinale
be
produced.
great
significance
related
On
out
between
and that of
the
types
the
cytotypes
2n=40
(2n=24,
are
sometimes
other hand
whereas in
crossable,
distinct
morphologically very
other
and
indicate
cases no
could
types
be
ease.
of these studies for the
elucidation
of taxonomic
problems
is discussed.
INTRODUCTION
The
L. and
species Symphytum officinale
intercross. The hybrid, Symphytum
a.o.
in Great
Britain
2n
=
=
2n
24,
48
=
and
40,
is widespread
Czechoslovakia and
have
to
a
also known from
the number 2n
The
species
(1951),
40
Symphytum
2n
in
=
48
Wade
Europe,
Western
&
Germany
distribution,
least
and Eastern
asperum
who found in material of
was
present authors, who found the number 2n
seemed obvious
great
to
Detailed
various
some
populations
cytological
Kliphuis
544
preliminary
morphological
Material
The
back-crossing
=
by
diploid plants
Netherlands.
Strey
by
seem
They
are
with
only.
(1931)
the numbers 2n
Grau
=
and
Britton
36 and 2n
(1968),
nor
=
the
by
32.
species
cytological
of the
The cytotype
Burgenland (Austria),
Netherlands
both
three cytotypes:
hybrid
are
and
able
to
intercross,
morphological
with both parents
is
it
studies.
said
to
(Wade).
In this paper
with.
with which
undertake combined
Moreover, repeated
occur
ease
by
Europe,
Germany. Hitherto, plants
studied
garden origin
in
studies revealed
1967).
The
in the
This could neither be confirmed
In view of the
in
tetraploid.
are
at
Lepech.areableto
widespread
Kliphuis
populations
many
40 have been found in the
Symphytum
respectively.
is
1958). Cytological
(Gadella
Italy, Hungary
=
asperum
uplandicum Nym.
Symphytum officinale is represented
restricted
more
X
(Tutin 1956;
that in the Netherlands
2n
2.
three
Symphytum asperum (2n=32), The results
and also of
and
results of
crossing experiments
and biometrical studies of plants
hybrids
will
be
published
our
previous
will be
dealt
belonging
to
(Gadella
&
later.
methods
methods
are
described in
paper
1967).
Acta hot. Need.
18(4), August
1969
CYTOTAXONOMIC
For
crossing
pollen
buds
STUDIES IN THE
corolla
At the
inserted
are
days
ripe
bags.
The seeds
the
crossing experiments
2n
b.
Symphytum officinale,
2n
=
c.
Symphytum officinale,
2n
=
results
on
of other
pollen
2n
were
the
tweezers
the
This
stigma.
plants
was
prevented
was
If this
importance.
however,
is
purple.
flowers
36;
=
red and
purple.
flowers blue.
32;
expected,
2n
hybrid
bluish.
Plants
of
garden
origin,
(see fig. 1):
This is
way.
could
for all cytotypes.
2n
=
40
(J.
be obtained in this way.
never
$
X
Symphytum officinale
2n
24
$
x
Symphytum officinale
2n
now],
not
did
white-flowered,
Many
attempts
The
germinate.
to
did
and
be
to
plant
hybrid
a
can
but
hybrid
is
is
24)
viable seeds
not
were
plants
=
used for
failed,
characterized
expected.
flowers
not
is
produce
from other
triploid hybrid)
true
Symphytum officinale
X
diploid plant (2n
till
the
(i.e.
pollen
$
40
=
is
able
the
this is
incompatibility
pollination
=
2n
plant
was
as
found up
vigorous
24
=
seeds
difficult.
very
harvested which
carry
flowers
that the colour of the flower of the
appeared
we
40;
used:
were
=
24
<J.
formed.
Symphytum officinale
be
flowers white.
could be obtained in this
Symphytum officinale
It
following cytotypes
24;
obtained
were
many attempts
No seeds
as
fact that the
of
pair
pure.
Symphytum officinale
Despite
to
a
any
pollination experiments.
No seeds
d.
in view of the
placed
was
48; flowers white,
=
asperum ”, 2n
not
following
Self
=
“
Symphytum
The
c.
asperum, 2n
Symphytum
probably
b.
7779 flower-
harvested after 3-6 weeks.
were
Symphytum officinale,
a.
pollen
later. Contamination by
a.
e.
(before
experiments,
RESULTS
For the
d.
emasculated
the corolla tube. With the aid of
on
time of anthesis the
two
by enveloping
3.
were
For these
anthesis).
removed.
was
repeated
flower buds
before
days
two
used. Emasculation of the flower is
easy
were
filaments
the
experiments
shed,
was
GENUS SYMPHYTUM 11.
48
pollination is of
be
once
=
obtained.
seed
a
white-flowering [which
always white-flowering,
the
by
up till
number 2n
now.
In view
=
36.
enveloped
by bags,
plot
so
to
that
the
is
far
as
This
of the
Also seeds formed after so-called
of the experimental
This,
could be
self
“open”
insects
could
stigma of this
germinate.
No seeds could be obtained ifthe
plant
used for
pollination
has red
or
purple
flowers.
e.
Symphytum officinale
Once
a
hybrid
tempts. Also
in
This hybrid has
f.
Symphytum
Acta Bot. Neerl.
2n
=
could be
this
not
case
the
flowered
officinale
2n
18(4), August
48
$
X
obtained
(2n
tetraploid
so
=
1969
Symphytum officinale
=
36)
after
plant (2n
=
2n
many
48)
=
24
unsuccessful
was
at-
white-flowering.
far.
40
$
x
Symphytum officinale
2n
=
48
$
and
545
TH. W.
Fig.
1.
Crossing-polygon, showing
and
Symphytum officinale
Double
circles
2n=32,
Black lines
unsuccessful
circles,
between
Symphytum
asperum
Lepech.
five
cytotypes (S. officinale: 2n=24, 40, 48; S.asperum:
garden origin, Bucuresti --).
connecting
double
circles
indicate
successful
hybridisation,
dotted
lines
hybridisation.
direction
The
relationships
KLIPHUIS
L.
the
represent
2n=36
the
J. GADELLA AND E.
of
between
the
the
arrows
double
corresponds
with
the
direction
circles, represent hybrids,
with
of
the
pollination. Single
chromosome
number
indicated.
The
g.
figures b/u
refer
Symphytum officinale
In both
cases
(also
2n
hybrids
=
=
can
be
descriptions given
48
$
x
Sympyhtum officinale
cytotypes 2n
hybrid
is
in the text.
=
40
characterized
reciprocally
and 2n
by
crossed with
2n
=
=
48
the number 2n
great
ease.
40 o'.
can
be crossed
=
44.
Their progeny,
44), is fully fertile.
Back-crossing
546
2n
f. and g. the
without difficulties. The
These
to the
of
the
hybrid
2n
=
44,
(obtained
by
Acta Bot.
the
of
the
Neerl. 18(4) August
,
1969
crossing
CYTOTAXONOMIC
cytotypes 2n
=
h.
46
=
They
i.
2n
asperum
The
made
parental types (2n
40 and 2n
=
48
=
42
=
32$
=
Symphytum
x
=
2n
40)
hybrids
2n
was
=
48
(only
$,
used).
have the chromosome number 2n
Symphytum
X
32$
2n
asperum
flowers and is
bluish-purple
=
36
=
48$
=
has
asperum 2n
Symphytum
2n
officinale
corolla
light purple
=
40.
easily.
hybrid (2n
Some
11.
with the chromosome numbers 2n
hybrids
hybrids, (flower bluish-purple),
were
Symphytum officinale
j.
with the
48)
=
resulted in
of the flower with
pollen
The
GENUS SYMPHYTUM
respectively.
Symphytum
the
THE
40 and 2n
respectively) always
and 2n
IN
STUDIES
from
this
cross.
32$.
produced easily.
Symphytum officinale
x
resulted
=
2n
They
40$.
=
have
bluish-purple
flowers.
k.
2n
Symphytum officinale
The
the
described
hybrids
ber 2n
l.
hybrids resulting
=
=
The
2n
=
48
Symphytum
x
asperum 2n
have the
experiment,
under). They
“
”
2n
asperum
$. (Flowers
=
32
$.
flower colour
same
characterized by the chromosome
are
as
num-
hybrids,
which
have
36 of
=
white
garden origin Ç
flowered
not
x
Symphytum officinale
light purple).
or
sofar, have
the
chromosome number
42.
Symphytum
m.
$
36.
Symphytum
2n
40
=
from this
officinale
2n
$
48
=
X
Symphytum
2n
“ asperum”
=
36
of
garden origin $.
The
hybrids
they
did
n-u.
all these
not
have the chromosome number 2n
come
crosses
Symphytum officinale
o.
Symphytum
p.
Symphytum
q.
Symphytum officinale
r.
Symphytum officinale
Symphytum
t.
Symphytum
u.
Symphytum
Summarizing,
asperum
2n
2n
“
”
2n
asperum
“
In
asperum
“
”
2n
asperum
asperum 2n
$
=
36
2n
=
24;
S.
2.
2n
=
32: S.
3.
2n
=
36:
a.
L.
officinale
asperum
S.
$
S.
S.
c.
S.
This
has
to
be
Acta Bot. Need.
now
(spring
1969)
$
x
Symphytum
36
=
32
$
36
X
$
x
”
“
Symphytum
”
Symphytum
can
be
”
asperum
interpreted
as
=
=
32
=
24
$.
36
c?.
36
<$.
40<?.
=
=
2n
$.
$.
=
2n
2n
asperum
2n
2n
asperum
“
24
2n
asperum
“
32
=
=
$.
36
<$.
follows:
Lepech.
L.
officinale
subsp.
L.
=
officinale
subsp.
asperum
Lepech. (2n
=
48)
X
S.
(2n
=
48)
X
S.
officinale
L.
24).
Lepech. (2n
tested
officinale
Symphytum officinale
X
asperum
(2n
2n
subsp. officinale (diploid).
officinale
nale
*
till
asperum 2n
Symphytum
X
Symphytum
subsp. officinale (2n
b.
Up
Symphytum officinale
x
=
=
Symphytum
x
X
24$
40
=
2n
$
32
=
2n
”
24
=
=
the various cytotypes
1.
42.
unsuccessful:
were
n.
s.
=
into flower,
uliginosum (Kern.)
=
=
Nym. (2n
=
40)
x
32).
32)
asperum
x
[S. officinale
Lepech. (2n
=
L.
subsp.
offici-
32]*.
experimentally.
18(4), August
1969
547
TH.
4.
2n
40:
=
a.
S.
b.
S.
officinale
L.
Lepech. (2n
2n
5.
42:
=
[5.
subsp.
L.
2n
44:
=
S.
officinale
L.
officinale
officinale
2n
46:
=
officinale
S.
subsp.
subsp.
L.
officinale
subsp.
officinale
(2n
(Kern.) Nym. (2n
8. 2n
4.
48:
=
S.
L.
officinale
KLIPHUIS
=
48)
S.
X
asperum
(2n
officinale
48)
=
=
(2n
X
S.
X
S.
40)
=
officinale
X
L.
40)].
=
(2n
48)
=
48)
=
“
asperum
”,
36).
=
subsp. uliginosum (Kern.) Nym. (2n
7.
(2n
officinale (2n
subsp.
garden origin (2n
6.
AND E.
uliginosum (Kern.) Nym.
subsp.
L.
officinale
S.
subsp.
uliginosum (Kern.) Nym. (2n
subsp.
b.
L.
officinale
GADELLA
32).
=
officinale
S.
a.
J.
subsp. uliginosum (Kern.) Nym.
L.
officinale
W.
S.
X
L.
officinale
40).
(2n
S.
x
48)
=
=
48)
=
[S.
X
L.
officinale
L.
officinale
subsp.
uliginosum
40)].
subsp. officinale, (tetraploid).
DISCUSSION
It is
clear that
least
the
three
and
diploids
the
to
diploids
results
limited
and
tetraploids
and
In
the
twice. In nature, in
the
with 2n
plants
hybrids
Symphytum
till
2n
=
from
36,
impossible
2n
=
asperum 2n
respectively.
spite
of the
origin.
In
officinale
the
=
cross
=
These
them with
of
view
type
they
548
in
hybrids
fact
more
of
at
assigned
hybrids
be
could
to a
(Rumania).
in
interfertile. Their
are
as
These
S.
X
(2n
it is
=
uplandicum
2n
=
could be
but it
appeared
Both cytotypes
Symphytum
36 and 2n
=
X
48)
with
obtained
were
=
uplandicum,
other and have
plants
uplandicum.
uplandicum
44)
is known
plants
32.
=
as
of
a
More
research,
year,
(1969),
40
in
different
Symphytum
highly probable that
with the chromosome number 2n
X
=
plants,
crossable with
Symphytum
Europe,
far
as
Other
difficulties,
asperum 2n
from each
tetraploid
only
Contrary,
hybrids (2n
certain extent,
herbarium studies. This
hybrids
X
found.
48 without
regarded
common
be
with the number 2n
slightly
Symphytum
S.
=
fully
are
of these
obtained
with.
met
to
extremely
an
possible.
asperum
hybrids
uplandicum
including detailed
of the
is
to
could be
never
cytological respect,
32
=
2n
that
are
Crossing
Symphytum
differ
be the
X
48)
Bucuresti
must
of the
be made to intercross the
crossing
of
from
slightly
and may be
be crossable
hybrid
a
Symphytum officinale
hybrids
fact that
hybrid Symphytum
necessary,
of
garden
48
=
Symphytum
32, resulting
seem to
commonest
differ
morphologically. According
to
seem
variable in
not
number 2n
Symphytum officinale
to
40
1967),
48 chromosomes
=
40 and 2n
=
asperum is
40 and 2n
=
Kliphuis,
garden
population,
40 and 2n
(2n
botanical
the
&
plants
experimental
which resemble
crossed with
with 2n
very similar
are
tetraploid
mixed
a
=
Only
now.
complex species consisting
very
also fertile and intercrossable.
are
with their
parents
up
a
plants
uliginosum (Kern.) Nym.
diploid
extent.
The
races.
tetraploids, (Gadella
subspecies
The
our
is
Symphytum officinale
cytological
=
the
40 is the
however,
is
attempts will
2n = 36and2n=40.Also back-
36 and
2n
=
40
Acta Bot. Neerl.
with the
parents
18(4), August
1969
CYTOTAXONOMIC
Symphytum
STUDIES IN
officinale
THE
2n
GENUS
40
=
SYMPHYTUM
and 2n
11.
will
48,
=
be
the
of further
objective
investigation.
The
32.
from
plants
from
cross
asperum 2n
phytum
Also the
hybrid
Symphytum
by crossing
Symphytum
“
2n
Symphytum
not
easy
Symphytum
officinale
”
give
to
in
the
experimental
2n
as
back-
a
asperum 2n
=
hybrids with Sym-
40
=
are
more
the
fertile,
any doubt that the
The
garden
42
=
origin
(obSym-
x
of these results. If the
species
The
S.
taxa
ease
indicates
garden)
number 2n
of
in detail.
interfertile.
fully
the
36
=
interpretation
an
represent distinct morphological species.
least
regarded
Symphytum
with
2n
asperum
are
differences indicate without
with
uplandicum
X
be
possibly
40
uplandicum
uplandicum hybrids
X
=
will be studied
48)
=
it is
Taxonomically
may
2n
prove this.
might
X
phytum officinale
and
Symphytum
32
=
36),
=
uplandicum
X
of the
Backcrossing
tained
Bucuresti, (2n
Symphytum
Symphytum
clearcut
that
and S.
officinale
with which
they
asperum
morphological
asperum
they hybridize (at
belong
the
to
same
biospecies (sensu Mayr).
is
Symphytum officinale
uplandicum
2n
In the Dutch
be
regarded
officinale
some
or
plants
2n
36,
=
province
of
Limburg
of
less
X
2n
uplandicum
the
intermediate
Symphytum
is also reflected
plants
X
Dolsberg,
=
in the
hybrids
found that could
possibly
40.
Near
morphologically
2n
=
uplandicum
=
Epen
(prov.
between
=
with
Wijlre (prov.
44
43,
of
36.
Symphytum
of
2n
=
Symphytum
plants
They are
48 and Sym-
Limburg)
The
Limburg),
found.
were
Symphytum officinale
chromosome number 2n
uplandicum
X
between
were
near
with the chromosome numbers 2n
found with
were
some
Symphytum
with S. asperum. On the
morphologically intermediate
phytum
which
40.
backcrosses
as
variable,
very
=
some
are
asperum 2n
plants
more
=
32
or
and
40.
ACKNOWLEDGEMENT
These
investigations
University
The
authors
carried
out
at
the
Verwey-Leenders. The
assistance
in
the Botanical
Prof. Dr. J.
(director
gratefully acknowledge
smit and Mrs. G.
tra for his
were
of Utrecht
correcting
the
Museum
and
Herbarium
of the
State
Lanjouw).
assistance of Miss Th.
authors express their
English
Dufhues,
gratitude to
Miss
mr.
M.
Groen-
L. Y. Th. Wes-
text.
REFERENCES
Britton, D.
M.
Gadella, Th.
I.
(1951): Cytogenetic
W. J. & E. Kliphuis
Symphytum
officinale
in
studies
on
the
Boraginaceae.
Brittonial:
(1967): Cytotaxonomic studies
the Netherlands.
Proc. Kon.
Ned.
in
the
Acad.
233-266.
genus
Symphytum.
Wetensch.
ser.
C 70:
378-391.
Grau,
J.
(1968); Cytologische Untersuchungen
an
Boraginaceen
I. Mitt. Bot.
Miinchen
7:
277-294.
Strey,
M.
Tutin, T.
Wade,
(1931): Karyologische
G.
A. E.
cum
(1956): The
(1958):
Nyman
Acta Bot. Need.
The
genus
history
in Britain.
Untersuchungen
Symphytum
of
Symphytum
Watsonia
18(4), August
1969
4:
an
in Britain.
Boraginoideae.
Watsonia
asperum
Lepech,
Planta
14:
683-730.
3:280-281.
and
Symphytum
x
uplandi-
117-118.
549