Abstract
Pollen characters were studied in 44 diploid, seven triploid and two tetraploid culti-vars of Primula sieboldii. Pollen diameter was larger as was the ploid level higher. The higher frequency (more than 1.0%) of giant pollen (about 1.5 tirnes larger than normal pollen) and lower pollen fertility (less than 85%) were found in the triploid and tetraploid cultivars suggesting their usefulness for convenient identification of polyploid cultivars. Unconscious selection of polyploid cultivars might be accomplished because morphological gain, associated with polyploidy itself, matched well with the breeding objectives such as large flower and long peduncle, suitable for the traditional manner of appreciation of this plant. This situation is very similar to that of the development of tetraploid cultivars in other horticultural primulas, i. e., P. malacoides. P. sinensis and P. obcoleica.
