Journal article
Heterosis In An Isolated, Effectively Small, And Self-Fertilizing Population Of The Flowering Plant Leavenworthia Alabamica
Evolution, Vol.60(1), pp.184-191
01/01/2006
Handle:
https://hdl.handle.net/2376/107506
Abstract
Mildly deleterious mutations are thought to play a major role in the extinction of natural populations, especially those that are small, isolated, or inbred. Self-fertilization should reduce the effective size of populations and simultaneously reduce migration between populations. A history of self-fertilization should therefore cause a population to harbor a substantial 'local drift load' caused by the fixation of mildly deleterious mutations. This hypothesis was tested in Leavenworthia alabamica, which contains large, self-incompatible populations and smaller self-compatible populations with adaptations for self-fertilization. The fitness of offspring from within- and between-population crosses was compared to quantify heterosis caused by the masking of deleterious alleles in the heterozygous state. Little heterosis was observed in crosses between five large, self-incompatible populations and two of the three small, self-fertilizing populations of L. alabamica. However, the most geographically isolated and genetically divergent self-fertilizing population (Tuscumbia) exhibited a 110.2% increase in germination and a 73.6% increase in fitness, which is consistent with a sizeable local drift load. The finding of substantial heterosis for fitness supports the idea that small effective size, reproductive isolation, and self-fertilization can make populations particularly vulnerable to mutation accumulation.
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Details
- Title
- Heterosis In An Isolated, Effectively Small, And Self-Fertilizing Population Of The Flowering Plant Leavenworthia Alabamica
- Creators
- J W Busch
- Publication Details
- Evolution, Vol.60(1), pp.184-191
- Academic Unit
- Biological Sciences, School of
- Identifiers
- 99900547025701842
- Language
- English
- Resource Type
- Journal article