Reproductive isolation of a new hybrid species, Senecio eboracensis Abbott & Lowe (Asteraceae)

Lowe, A. J. and Abbott, R. J. (2004) Reproductive isolation of a new hybrid species, Senecio eboracensis Abbott & Lowe (Asteraceae). Heredity, 92 5: 386-395. doi:10.1038/sj.hdy.6800432

Author Lowe, A. J.
Abbott, R. J.
Title Reproductive isolation of a new hybrid species, Senecio eboracensis Abbott & Lowe (Asteraceae)
Journal name Heredity   Check publisher's open access policy
ISSN 0018-067X
Publication date 2004
Sub-type Article (original research)
DOI 10.1038/sj.hdy.6800432
Volume 92
Issue 5
Start page 386
End page 395
Total pages 10
Editor R. A. Nichols
Place of publication UK
Publisher Nature Publishing Group
Collection year 2004
Language eng
Subject C1
270700 Ecology and Evolution
780105 Biological sciences
Abstract The nature and extent of reproductive isolation was examined between a new self-compatible hybrid species Senecio eboracensis (2n = 40) and its parents, self-incompatible S. squalidus (2n = 20) and self-compatible S. vulgaris (2n = 40). The triploid F-1 of S. eboracensis x S. squalidus exhibited very low seed set ((x) over bar = 0.63%), and F-2 and F-3 progeny were able to recover nominal levels of fertility ((x) over bar = 23.9 and 9.7%), while F-1 and F-2 offspring of S. eboracensis x S. vulgaris showed reduced seed set ((x) over bar = 63.8 and 58.8%). In both cases, evidence from previous work indicates that reduced fertility is associated with meiotic chromosome mispairing, and is a likely consequence of recombining both parental genomes within this new taxon. No hybrid offspring between S. eboracensis and S. squalidus were found in the wild, and only one such hybrid was recorded among 769 progeny produced by S. eboracensis surrounded by S. squalidus on an experimental plot. Natural crossing between S. eboracensis and S. vulgaris was recorded to be very low (between 0 and 1.46%) in the wild, but rose to 18.3% when individuals of S. eboracensis were surrounded by plants of S. vulgaris. It was concluded that strong breeding barriers exist between the new hybrid species and its two parents. Prezygotic isolation between S. eboracensis and S. vulgaris is likely to be largely due to both species reproducing by predominant self-fertilisation. However, differences recorded for germination, seedling survival, time of flowering and characters associated with pollinator attraction, plus significant clumping of juvenile and adult conspecifics in the wild, probably also contribute to reproductive isolation and ecological differentiation.
Keyword Genetics & Heredity
Reproductive Isolation
Ray Floret Locus
Vulgaris L
Penstemon Scrophulariaceae
Outcrossing Frequency
Radiate Groundsel
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Integrative Legume Research Publications
2005 Higher Education Research Data Collection
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Citation counts: TR Web of Science Citation Count  Cited 30 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 31 times in Scopus Article | Citations
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Created: Wed, 15 Aug 2007, 03:07:57 EST