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ARS Home » Southeast Area » Miami, Florida » Subtropical Horticulture Research » Research » Publications at this Location » Publication #338298

Research Project: Genetic Characterization, Genetic Improvement, and Best Horticultural Management Practices for Subtropical/Tropical Ornamental Germplasm

Location: Subtropical Horticulture Research

Title: Will the same ex situ protocols give similar results for closely related species?

Author
item Griffith, Patrick - Montgomery Botanical Center
item Calonje, Michael - Montgomery Botanical Center
item Meerow, Alan
item Francisco-ortega, Javier - Florida International University
item Knowles, Lindy - Bahamas National Trust
item Tut, Freddy - Belize Botanic Gardens
item Sanchez, Vanessa - Miami University - Ohio
item Hird, Abby - Botanic Gardens Conservation International
item Noblick, Larry - Montgomery Botanical Center
item Magellan, Tracy - Montgomery Botanical Center

Submitted to: Biodiversity and Conservation Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2017
Publication Date: 7/10/2017
Citation: Griffith, P.M., Calonje, M., Meerow, A.W., Francisco-Ortega, J., Knowles, L., Tut, F., Sanchez, V., Hird, A., Noblick, L.R., Magellan, T.M. 2017. Will the same ex situ protocols give similar results for closely related species? Biodiversity and Conservation Journal. 26(12):2951-2966. doi:10.1007/s10531-017-1400-2.
DOI: https://doi.org/10.1007/s10531-017-1400-2

Interpretive Summary: Conservation of threatened plant species often requires offsite living collections. Protocols for developing these collections most often emphasize sampling depth, but little is known about the genetics of such collections. This study compares how well a single collecting protocol can capture the diversity in wild populations of two closely related species. We selected two related species, bay rush (Zamia lucayana) and sinkhole cycad (Zamia decumbens), based on similarities and differences that allow for rigorous comparison, including geographic isolation and reproductive factors. For each species, we compared on site plants to off site plants using the same 10 molecular markers. Structured resampling of allele capture from the on site populations by the off site collections shows that allele capture increases as number of off site plants maintained increases, but with a diminishing rate of increase. Difference in the rate of allele capture between the two species was significant but modest. At larger collection sizes, the difference in rate of allele capture showed a high practical significance. These data illustrate that a unified collecting protocol can achieve similar allele capture among related species, but also that geographic and reproductive factors can influence the rate of allele capture.

Technical Abstract: Conservation of imperiled plant species often requires ex situ (offsite) living collections. Protocols for developing these collections most often emphasize sampling depth, but little is known about the genetics of such collections. This study compares how well a single collecting protocol can capture the diversity in wild populations of two closely related species. We selected two exemplar species, bay rush (Zamia lucayana) and sinkhole cycad (Zamia decumbens), based on similarities and differences that allow for rigorous comparison, including geographic isolation and reproductive factors. For each species, we compared in situ plants to ex situ plants via the same panel of 10 microsatellite markers. Genetic distance analysis shows high fidelity of the ex situ collections to their in situ source populations and sub-populations. Structured resampling of allele capture from the in situ populations by the ex situ collections shows that allele capture increases as number of ex situ plants maintained increases, but with a diminishing rate of increase. Difference in the rate of allele capture between the two species was significant at the a = 0.1 level, (p = 0.097) but not at the a = 0.05 level. At larger collection sizes, the difference in rate of allele capture showed a high practical significance (d = 5.41). These data illustrate that a unified collecting protocol can achieve similar allele capture among related species, but also that geographic and reproductive factors can influence the rate of allele capture.