Inbreeding depression in Nigella degenii (Ranunculaceae): Fitness components compared with morphological and phenological characters
Publikation/Tidskrift/Serie: International Journal of Plant Sciences
Förlag: University of Chicago Press
We have compared selfed and outbred offspring from individual plants of the annual plant Nigella degenii to examine patterns of inbreeding depression in two direct components of fitness ( flower number and pollen viability) and a number of morphological or phenological characters for which the optimal phenotype may be habitat specific. Selfing lowered flower number, plant height, flower size, and pollen viability and caused a shift toward later germination and flowering dates. There was no significant difference in inbreeding depression between fitness components and characters reflecting morphology or phenology regardless of how inbreeding response was estimated. Family-level analyses revealed moderately strong correlated responses involving flower number and each of the nonfitness characters, whereas pollen viability showed an independent response to inbreeding. On the basis of these observations, we hypothesize that morphology and phenology could make a significant contribution to lifetime inbreeding depression in N. degenii, that inbreeding responses in different types of characters involve loci with both general and specific effects on the phenotype, and that morphological inbreeding depression has contributed to the evolutionary reduction of floral structures so prevalent in the Nigella arvensis complex.
- ISSN: 1058-5893