2016 journal article

Disruption of endosperm development is a major cause of hybrid seed inviability between Mimulus guttatus and Mimulus nudatus

NEW PHYTOLOGIST, 210(3), 1107–1120.

By: E. Oneal *, J. Willis * & R. Franks n 

author keywords: endosperm; hybrid inviability; Mimulus guttatus (monkeyflower); pollen-pistil interactions; postzygotic isolation; seed development
MeSH headings : Crosses, Genetic; Endosperm / embryology; Fruit / growth & development; Germination; Hybridization, Genetic; Mimulus / embryology; Mimulus / genetics; Phenotype; Pollen Tube / growth & development; Self-Fertilization; Staining and Labeling; Sympatry
TL;DR: Light is shed on the extent of developmental variation between closely related species within the M. guttatus species complex, an important ecological model system, and a partial mechanism for the hybrid barrier between M. Guttatus and M. nudatus is provided. (via Semantic Scholar)
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2. Zero Hunger (Web of Science)
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15. Life on Land (OpenAlex)
Source: Web Of Science
Added: August 6, 2018

Summary 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.