Abstract Detail


Santee , Mathilda Viola [1], Barrett, Craig [2].

Integrative species delimitation in Californian striped coralroot orchids.

Mycoheterotrophic plants partially or fully rely on fungal hosts to survive, however, their rare parasitic nature results in challenging taxonomic definitions as morphology can be variable, leading to difficult conservation efforts. Corallorhiza striata (striped coralroot) is a rare, leafless orchid found in the western United States, Canada, and Mexico. It fully relies upon ectomycorrhizal fungi to obtain energy, as it has lost the ability to photosynthesize effectively which has classified it as a mycoheterotrophic plant. With widespread populations, this orchid complex gives excellent insight into long-term molecular and species evolution by geographical isolation. Multiple populations and variants have formed across North America, including Corallorhiza striata var. striata, var. vreelandii; and two distinct species, C. bentleyi and C. involuta. We are interested in determining the relationship between populations found in coastal California to those of the Sierra Nevada mountains to assess if these can be classified as one “Californian” taxon. Taxonomic status among members of this complex are poorly understood, but this information is crucial for conservation efforts for these rare orchids. We used three types of data, morphology, genomics, and fungal associations, to investigate variation in members of the C. striata complex across North America. Specifically, preliminary data show mixed evidence for genetic and morphological divergence between coastal Californian and Sierra Nevadan populations. Morphological, plastid, and fungal host data show some differentiation among individuals from the Sierra Nevada and coastal ranges, however, nuclear ISSR banding patterns show a lack of differentiation. We are conducting a novel approach to genotyping via Inter-Simple Sequence Repeats (ISSR) amplicons to further study the nuclear genomic variation. We aim to determine evolutionary history, environmental niche overlap among populations, and adaptation to effectively target fungal host genotypes by means of single nucleotide polymorphism (SNP) detection. ISSR-seq has the potential to be used across diverse subdisciplines in biology as an economical and straightforward sequencing tool. We are using the ISSR-seq protocol on 88 samples found widespread in the C. striata complex to determine genetic diversity within and between species to further define species boundaries. We amplified specific ISSR regions using 8 PCR primers, followed by library amplification to prepare for Illumina sequencing. Impacts of this research include an increased understanding of the forces that drive diversification in mycoheterotrophic plant species, as well as awareness and conservation of this rare orchid complex.

1 - West Virginia University, Biology, 53 Campus Dr, Morgantown, WV, 26506, USA
2 - West Virginia University, Biology, 53 Campus Drive, Life Science Building 5218, Morgantown, WV, 26506, United States

SNP detection
Species Complex
cryptic species
rare species.

Presentation Type: Poster
Session: P, Systematics Posters
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 5:00 PM Time and date to be determined
Number: PSY002
Abstract ID:177
Candidate for Awards:None

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