thumbnail

The genetic basis of speciation in the Giliopsis lineage of Ipomopsis (Polemoniaceae)

Heredity

By:
, ,
DOI: 10.1038/hdy.2013.41

Links

Abstract

One of the most powerful drivers of speciation in plants is pollinator-mediated disruptive selection, which leads to the divergence of floral traits adapted to the morphology and behavior of different pollinators. Despite the widespread importance of this speciation mechanism, its genetic basis has been explored in only a few groups. Here, we characterize the genetic basis of pollinator-mediated divergence of two species in genus Ipomopsis, I. guttata and I. tenuifolia, using quantitative trait locus (QTL) analyses of floral traits and other variable phenotypes. We detected one to six QTLs per trait, with each QTL generally explaining small to modest amounts of the phenotypic variance of a backcross hybrid population. In contrast, flowering time and anthocyanin abundance (a metric of color variation) were controlled by a few QTLs of relatively large effect. QTLs were strongly clustered within linkage groups, with 26 of 37 QTLs localized to six marker-interval ‘hotspots,’ all of which harbored pleiotropic QTLs. In contrast to other studies that have examined the genetic basis of pollinator shifts, our results indicate that, in general, mutations of small to modest effect on phenotype were involved. Thus, the evolutionary transition between the distinct pollination modes of I. guttata and I. tenuifolia likely proceeded incrementally, rather than saltationally.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The genetic basis of speciation in the Giliopsis lineage of Ipomopsis (Polemoniaceae)
Series title:
Heredity
DOI:
10.1038/hdy.2013.41
Volume
111
Year Published:
2013
Language:
English
Publisher:
Nature Publishing Group
Contributing office(s):
Southwest Biological Science Center
Description:
11 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Heredity
First page:
227
Last page:
237
Number of Pages:
11