Characteristics of infructescence and seed yield in a Primula hybrid zone

Hybridisation between Primula vulgaris and P. veris was investigated along a southwest exposed slope in a woodland in Hungary. Parent species and hybrids were identified by colour and size of the flowers. The two morphs within each taxon showed only slight differences, but discrimination of the three taxa was unambiguous. Scape and pedicel length proved to be suitable for distinguishing hybrids from P. veris on the basis of inflorescence architecture. Seed yield components showed considerable differences between the two parent species: P. veris produced more and lighter seeds per capsule than P. vulgaris did. Hybrids also differed significantly from the parent species: hybrids had the fewest and heaviest seeds per capsule among the three taxa. The two parent species did not show the slightest sign of gender specialisation: fruit number per plant, fruit set, and seed number per capsule were equal in long-styled and short-styled morphs. The two morphs, however, were not equally successful in hybrids: fruit number per plant and fruit set were significantly lower in long-styled plants than in short-styled plants, although the long-styled morph with highly exserted stigmas was expected to be in more favourable situation for pollination