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THE RESULTS THE STUDIES OF CHAENOMELES
FLOWER BUD DEVELOPMENT,
POLLINATION AND FERTILISATION
Dr.E. Kaufmane
Dobclc Horticulture Plant Breeding Experimental Station,Latvia
This research was done at the Swedish Institute of horticultural
plant Breeding Balsgord, in March-August,
1994,
along several
lines using
60
Chaenomeles genotypes from Balsgord and Do-
bele. The usual cytoembriological methods and the flourescence
method were used. A general understanding of the development of
the generative sphere of this species, .and its pecularities, was
reached. The male gamrtophyte of all the genotypes develops
normally and results in binuclear pollen. They are ready to take
part in pollination
5
to
7
days before flower opening. Significant
differences were observed in pollen fertility in artificial en\iron-
ment-from 0% to 86,6% depending on the genotype. All the
studied genotypes had normal development of the female ga
metes. a ripe octanuclear embryo sack develops
2
to
4
days after
the flower opening (depending on the genotype). It was observed
that in artificial pollination with own pollen for
35
Chaenomeles
genotypes,
43%
of the plants had the fruits set. The percent of fruit
set at the phase of ripe fruits varies:
1,4° о
to
47%.
So, contrary to
the traditional opinion, Chaenomeles have a tendency to self fer
tility. Studying pollination and fertilization with the fluorescence
microscope, it W'as observed that most of the genotypes have good
germination of pollen on the stygma, but the way of pollen tubes
in the tissue of the pistil and the process of fertilisation differ sig
nificantly depending on thepollination combination. At pollina-
.tion with own pollen the pollen tubes usually grow' shorter and in a
less dense cluster, the fertilisation occurs after
120
to
1444
hours.
At cross-pollination (with mixed pollen) the pollen tubes reach
the base of the ovary* already afler
24
to
72
hours, hut the fertili
sation occurs after
48
to
96
hs.since pollination (dq)endens on the
genotype).
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