Abstract

We investigated the occurrence of herkogamy and dichogamy in 43 populations of the grassland biennial Gentianella campestris in Sweden, and experimentally tested their significance for the reproductive system of the species. Furthermore, we performed a heritability test to evaluate the potential for selection on traits related to herkogamy. Dichogamy did not occur in the studied populations, and herkogamy was restricted to five populations. Two types of herkogamy were found, one with the stigma protruding above the anthers (hyper-stigmatic), and one with the stigma positioned below the anthers (hypo-stigmatic). In both types, the stamens elongated during anthesis. In the hyper-stigmatic plants, the anthers reached and pollinated the stigma after c. 3-4 days. This did not occur in hypo-stigmatic plants. Pollination experiments showed that the plants were self-compatible and that elongation of stamens provided a mechanism for reproductive assurance in hyper-stigmatic plants. The type of herkogamy did not differ between flowers of the same developmental stage within a plant. In two of the five herkogamous populations, the herkogamy differed between plants, but there was a normal distribution of the anther-stigma separation. Herkogamy was not related to population size. A comparison of the anther-stigma separation of self-pollinated mother plants and their offspring showed that herkogamy was a highly heritable trait (average h(2) = 0.85), that clearly has the potential to respond to selection.

Keywords

autofertility; dichogamy; Gentianella campestris; flower morphology; herkogamy; heritability; pollination; reproductive system

Published in

Basic and Applied Ecology
2000, Volume: 1, number: 1, pages: 69-81

SLU Authors

• Lennartsson, Tommy

  • Department of Conservation Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Developmental Biology
Ecology
Botany


Publication identifier

DOI: https://doi.org/10.1078/1439-1791-00011

Permanent link to this page (URI)

https://res.slu.se/id/publ/101828