Abstract Detail

Frontiers in Botany: Environmental DNA as an Emerging Tool for Measuring, Monitoring, and Managing Plant Biodiversity

Freeland, Joanna [1], Wilson, Chris [2], Marinich, Allison [3], Currier, Charise [3], Wozney, Kristyne [2], Coghlan, Stephanie [3], Shafer, Aaron [3].

Are eDNA assays useful for detecting aquatic invasive plants? A three-part case study based on invasive water soldier (Stratiotes aloides) populations in Canada.

Plant surveys based on assays of environmental DNA (eDNA) from water samples have been greatly underutilized compared to those conducted on many aquatic animal taxa, and this may be partly attributable to methodological challenges. Here we present the results of three studies that collectively investigated different methods for assaying eDNA from the invasive aquatic plant Stratiotes aloides (water soldier) based on water samples from two river sites in southern Ontario, Canada: Seymour Lake (Trent River) and Black River. Water soldier eDNA was successfully isolated from some river water samples; however, despite Seymour Lake having a large established population, eDNA was detected by qPCR assays infrequently, and typically at low amounts, from samples collected at the peak of the growing season in July. Sampling from later in the year (October or November) was more likely to detect eDNA from Seymour Lake, and also detected eDNA from Black River where plants had recently been eradicated. qPCR assays also showed that the size of the amplified product influenced detection results: primers targeting relatively large (437 bp) fragments of the rbcL gene seldom generated positive results, whereas a primer-probe combination that amplified a relatively short (107 bp) region of the same gene was more likely to identify eDNA, although still inconsistently and with typically low copy numbers. In contrast, a metabarcoding study based on a ~221 bp region of rbcL was more sensitive, and identified S. aloides from all tested water samples collected from Seymour Lake in July, and from Black River in October. Collectively these data show that eDNA detection can be effective for detecting plant species of interest, but that practitioners should factor species seasonal ecology (growth vs. decay timing) and assay sensitivity into experimental designs.

1 - Biology, C251 LHS Bldg, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada
2 - Ontario Ministry of Natural Resources and Forestry, 300 Water Street, Peterborough, Ontario, K9J 8M5, Canada
3 - Trent University, Biology, 1600 West Bank Drive, Peterborough, Ontario, K9L 0G2 , Canada

Keywords:
Aquatic plants
invasive plants
eDNA
plant surveys  
Stratiotes aloides.

Presentation Type: Symposium Presentation
Session: SY3, Frontiers in Botany: Environmental DNA as an Emerging Tool for Measuring, Monitoring, and Managing Plant Biodiversity
Location: /
Date: Tuesday, July 20th, 2021
Time: 10:15 AM(EDT)
Number: SY3002
Abstract ID:672
Candidate for Awards:None