ibclogo XVI International Botanical Congess


Abstract Number: 5804
Poster No. = 1127


POLLEN POLYMORPHISM IN THE ORDER VIOLALES.


Gavrilova, O.A., Komarov Botanical Institute RAS, 2 prof. Popov str., St-Petersburg, 1997376 Russia


The 20 from 95 species in the order Violales (from 56 genera of Violaceae, Flacourtiaceae, Lacistemataceae, Berberidopsideaceae, Aphloiaceae, Kiggelariaceae, Turneraceae) have different pollen form in one specimen. For all studied species the typical pollen is 3- or 4-colporate. But in some patterns have been discovered also 2-aperturate, 3-aperturate with merged colpa, 4-5-6-aperturate with different position of colpa. The main part of these specimens contains 5-15% of deviate grains and two or more pollen modifications. Various pollen forms occur mainly in the tribe Casearieae or in the genus Viola, in other taxons this phenomenon have been found very rarely. But two genera (Trychostephanus, Viola) demonstrate the most variety of the pollen types up to 50% of abnormal grains. In this case the pollen may be crumpled, with deformated surface, has diverse dimensions. This unusual occurrence have been shown for plants, which gro in small isolated populations or gibrids, and probably, connect with disturbance of meiotic process or pollen development. The existence of different pollen forms for 3-aperturate pollen patterns confirms the possibility of formation of 4-5-aperturate types on the base of 3-aperturate.


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