Abstract Detail



Systematics

Saunders, Theresa [1], Johnson, Leigh [2].

Resolving relationships in Aliciella subsection Subnuda (Polemoniaceae): high levels of chloroplast capture revealed by comparative DNA sequencing.

Aliciella subsection Subnuda contains six species of perennial flowering plants, A. tenuis, A. caespitosa, A. subnuda, A. haydenii, A. formosa, and A. cliffordii, three of which are rare and face significant threats to their populations. Gilia karenae was recently described as a member of the polyphyletic genus from which Aliciella has been segregated, but there is some suspicion that it is synonymous with A. tenuis. We used molecular analysis to assess G. karenae’s relationships with other members of subsection Subnuda. Our data was used to infer the phylogeny of subsection Subnuda and consists of four DNA regions: the nuclear ribosomal internal transcribed spacer (ITS), and three chloroplast regions: trnS–trnG intergenic spacer, trnL–trnF intron and intergenic spacer, and ycf6–psbM intergenic spacer. While similar in some aspects, the ITS and chloroplast DNA revealed different phylogenies. Both ITS and chloroplast DNA supported the placement of G. karenae into subsection Subnuda and further suggest it as conspecific with A. tenuis. The chloroplast DNA revealed an unexpected history of repeated chloroplast capture within the subsection. Aliciella tenuis has four distinct cpDNA haplotype groups all sharing a common nrITS region (with minimal random variation throughout its range). This suggests there have been three distinct chloroplast capturing events from three different species. Two of these species are known: A. subnuda and A. caespitosa, and both can be readily distinguished from A. tenuis morphologically and by their nrITS.  A third cpDNA haplotype group includes G. karenae, which lacks unique morphological apomorphies relative to A. tenuis, and shares the same nrITS repeat.  We hypothesize that chloroplast capture with an as yet undiscovered or perhaps now extinct species explains the remaining cpDNA haplotype group.


1 - Brigham Young University, Biology, 4102 LSB, Brigham Young University, Provo, UT, 84602, USA
2 - Brigham Young University, Deptartment Of Biology, 4102 LSB, Provo, UT, 84602, United States

Keywords:
cpDNA
Introgression
Cytonuclear discordance.

Presentation Type: Oral Paper
Number:
Abstract ID:171
Candidate for Awards:George R. Cooley Award


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