Abstract Detail

Systematics

Cohen, Dylan [1].

Herbarium Genomics: Testing for phylogenetic signal and assessing rarity in Chilean Loasaceae.

Loasaceae (rock nettle family) are diverse in western North America and in the Andes of South America. Until recently, Loasa was the largest genus in Loasaceae. However, important traits such as androecium morphology were underutilized, and incomplete reproductive material on herbarium specimens resulted in an unsatisfactory classification. Taxonomy of Loasa became especially challenging after historic collections, including types from the 1700s, were destroyed during WWII. Despite these challenges, more recent research has resulted in separation of five genera from Loasa. One recent segregate, Grausa, is composed of vining and rosette plants. This genus was established with limited taxon sampling and species relationships are not understood. In southern Chile, Grausa is uncommon and increasingly threatened by agriculture, invasive plants, and habitat destruction. Delimiting species is crucial for conservation and ecological applications. However, lack of freshly collected plant material has prevented inference of species relationships in Grausa. The goal of this study was to use Rad-Seq methods to gather DNA data from herbarium and field collections to 1) test the current classification of Chilean Loasaceae and 2) elucidate species relationships within Grausa. The result is a fully supported hypothesis of relationships. The recent segregates from Loasa are supported; however, Grausa is not monophyletic. Instead, species are placed in two separate clades. Differences in nectar scale morphology support molecular results for Grausa. Grausa s.s. contains both vining and rosette plants, whereas the separate Grausa-2 clade contains only vining plants. Rad-Seq is a method that works well for herbarium material, but field work is still essential to understand morphological characters as well as to assess ecological aspects such as rarity.

1 - Rancho Santa Ana Botanic Garden, 1500 North College Ave, Claremont, CA, 91711, United States

Keywords:
Loasaceae
Loasa
Chile
herbarium
RAD-seq
systematics
Andes.

Presentation Type: Oral Paper
Session: SYS2, Systematics II: Rosids part 1 to Asterids part 1
Location: Tucson G/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 11:15 AM
Number: SYS2013
Abstract ID:894
Candidate for Awards:None