Disruption of endosperm development is a major cause of hybrid seed inviability between Mimulus guttatus and Mimulus nudatus.
Published
Journal Article
Divergence of developmental mechanisms within populations could lead to hybrid developmental failure, and might be a factor driving speciation in angiosperms. We investigate patterns of endosperm and embryo development in Mimulus guttatus and the closely related, serpentine endemic Mimulus nudatus, and compare them to those of reciprocal hybrid seed. We address whether disruption in hybrid seed development is the primary source of reproductive isolation between these sympatric taxa. M. guttatus and M. nudatus differ in the pattern and timing of endosperm and embryo development. Some hybrid seeds exhibit early disruption of endosperm development and are completely inviable, while others develop relatively normally at first, but later exhibit impaired endosperm proliferation and low germination success. These developmental patterns are reflected in mature hybrid seeds, which are either small and flat (indicating little to no endosperm) or shriveled (indicating reduced endosperm volume). Hybrid seed inviability forms a potent reproductive barrier between M. guttatus and M. nudatus. We shed light on the extent of developmental variation between closely related species within the M. guttatus species complex, an important ecological model system, and provide a partial mechanism for the hybrid barrier between M. guttatus and M. nudatus.
Full Text
Duke Authors
Cited Authors
- Oneal, E; Willis, JH; Franks, RG
Published Date
- May 2016
Published In
Volume / Issue
- 210 / 3
Start / End Page
- 1107 - 1120
PubMed ID
- 26824345
Pubmed Central ID
- 26824345
Electronic International Standard Serial Number (EISSN)
- 1469-8137
International Standard Serial Number (ISSN)
- 0028-646X
Digital Object Identifier (DOI)
- 10.1111/nph.13842
Language
- eng