REGULATION OF POLLEN PRODUCTION IN ANTHRISCUS-SYLVESTRIS, AN ANDROMONOECIOUS SPECIES

Pollen production per anther was investigated in relation to the gender and biomass of the flowers, their positions in the umbel, the number of flowers, the proportion of male flowers, and the sequence of flower development (order of umbel) in the common European andromonoecious species Anthriscus sylvestris. Male flowers have significantly less pollen per flower than perfect flowers. Both in male and in perfect flowers, pollen amount per flower does not change much with the sequence of flower development while, at the same time, the proportion of male flowers significantly increases, to almost 100% in quaternary umbels. Pollen production per flower does not depend on the position of the flower in the inflorescence and is weakly correlated with the investigated variables, except for the rudimentary quaternary umbels. The pollen production per flower in quaternary umbels is significantly lower, and flower mass explains up to 80% of the variation. The data support the hypothesis that in andromonoecious species pollen output is regulated at the level of flower production rather than pollen per flower.