39 / 90
For the investigated flowers of
Swertiaperrenis
the P:0 ratio values correspond
to the range of values correlated by Dafni (1992) to obligate xenogamy
(Tables 1 and 3, Fig. 9).
The P :0 ratio values of the investigated flowers of
Centaurium erythraea
correspond to the maximum published by Dafni (1992) for facultative autogamy
and minimum for facultative xenogamy (Tables 1 and 3, Fig. 10).
CONCLUSIONS
The results of the investigation of the breeding systems of
Gentianaceae
taxa obtaind by the two alternative methods - PrO ratio method, and exclusion
and hand-pollination techniques are similar (Table 3).
Self-fertilization is rare in perennial plants but occurs often in annuals
(St eb b ins, 1974; R i c h a r d s , 1990, 1996). For the investigated by us
perennials this dependence is well confirmed in
Gentiana lutea, G. asclepiadea,
Swertia perrenis
and to some extent in
G. punctata.
They have comparatively
high values of P :0 ratio indicating obligate xenogamy (Table 3, Figs. 11 and
12). Mediate position within the investigated taxa with P :0 ratio values
corresponding to facultative xenogamy show the perennial
G. pyrenaica
and
the monocarpic
Gentianella bulgarica.
The lowest values of P :0 ratio indicating
facultative autogamy (with a transition from facultative xenogamy rather than
to it) are recorded for two other monocarpic taxa -
Gentiana utriculosa
and
Centaurium erythraea.
Interesting are the values of P :0 ratio recorded for the perennial
Gentiana
vema
which does not spontaneously self-pollinate. According to them this
species belongs to the group of facultative autogamy - facultative xenogamy.
Gentiana vema
and
G. utriculosa
belong to sect.
Calatianae
Froelich together
with
G. nivalis
(Tu t i n , 1972). The last one is another monocarpic self
fertilizer ( Кожу х а р о в а , 1994; Ko z u h a r о va, 1998,1999; K o z u h a r ova,
An c h e v , 2002). This indicates a transition from xenogamy to autogamy at
a level of the whole section. According to some authors at the base of the
intraspecific phylogenetic scheme is the primitive sect.
Gentiana
while sect.
Calatianae
F г о e 1i c h is highly evolved ( К у з н е ц о в , 1894; S c h a r f f e t e r ,
1953; С е р е б р я к о в а , 1979). If we correlate to this scheme the breeding
systems we observe gradual transition from obligate xenogamy in section
Gentiana
with self-incompatibility in the typical
G. lutea,
which breaks in
G.
lutea
ssp.
symphiandra,
through facultative xenogamy to facultative autogamy
in sect.
Calatianae
F r o e l i c h .
Acknowledgements:
Our special thanks to Prof. E. Bozilova, Prof. A. Dafni and Prof. A. J.
Richards for the interest in our work and the support. Thanks to Dr. E. Tasheva and. Dr. H.
Tzachev for the help in data computing and presentation.
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Электронная Научная СельскоХозяйственная Библиотека