Abstract Detail

Systematics Section/ASPT

Prebble, Jessica [1], tate, Jennifer [2], Meudt, Heidi [3], Symonds, Vaughan [1].

The complexity of delimiting species in a mostly selfing species group. How many species in the Myosotis pygmaea group?

The first step in understanding how population genetic variation is structured in rare plants compared to their common relatives is to delimit the species in question. Following the general lineage concept and using multiple lines of evidence, including population genetic data from microsatellites and morphological data from herbarium specimens, we explore species delimitation in a group of Myosotis (Boraginaceae) species endemic to New Zealand. The ultimate goal of this research is to assess whether there are differences in population genetic structure or variation between naturally uncommon species and those that are thought to be rare due to human-influenced decline. To do this, however, the question of how to define species boundaries in a mostly selfing, widespread species complex must first be addressed. The genus Myosotis (Boraginaceae) is found in both the Northern and Southern Hemispheres, with one of its centres of diversity located in Australasia where more than 40 species are currently described. Low levels of genetic diversity, recent radiation and suspected hybridisation have been found in the New Zealand representatives of this genus, which present some challenges to reconstructing evolutionary relationships and delimiting species. Our research focuses on the mostly selfing Myosotis pygmaea species group, which comprises five named species, four of which are threatened. We first address whether all five of these entities are actually conspecific, and whether additional, as-yet-undescribed species are also a part of this group. We here present results including analyses of a microsatellite dataset based on 12 markers and over 500 individuals, in conjunction with a morphometric analyses based on 100 individuals. Taken together, our results point to complex population differentiation within the species group. Not all genetic variation can easily be correlated with geographic or morphological variation. However, we are able to draw some conclusions regarding the number of species present within this group. Furthermore, the New Zealand Myosotis pygmaea species group is an excellent study system for exploring aspects of the nature of rarity. We compare the population genetic structure from widespread non-threatened species with that of threatened, range-restricted species to determine the relationship between distribution, population and species genetic diversity and conservation status. This research will have important taxonomic and conservation outcomes regarding threatened species in the unique New Zealand flora, particularly the endemic forget-me-nots.

1 - Massey University, Institute of Fundamental Sciences, Private Bag 11222, Palmerston North, 4442, New Zealand
2 - Massey University, Private Bag 11222, Palmerston North, N/A, 4442, New Zealand
3 - Museum Of New Zealand Te Papa Tongarewa, PO Box 467, Cable St, Wellington, N/A, 6140, New Zealand

Keywords:
Boraginaceae
Species delimitation
Microsatellites.

Presentation Type: Oral Paper:Papers for Sections
Session: 19
Location: Salon 9/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:00 PM
Number: 19014
Abstract ID:167
Candidate for Awards:None