Seed Cryopreservation and Germination of Rhus glabra and the Critically Endangered Species Rhus michauxii

Gerald S Pullman; Kylie Bucalo; Ron O Determann; Jennifer M Cruse-Sanders

doi:10.3390/plants10112277

Seed Cryopreservation and Germination of Rhus glabra and the Critically Endangered Species Rhus michauxii

Plants (Basel). 2021 Oct 24;10(11):2277. doi: 10.3390/plants10112277.

Authors

Gerald S Pullman^{1

2}, Kylie Bucalo¹, Ron O Determann³, Jennifer M Cruse-Sanders^{3

4}

Affiliations

¹ Renewable Bioproducts Institute, Georgia Institute of Technology, 500 10th Street NW, Atlanta, GA 30332, USA.
² School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
³ Department of Conservation Research, Atlanta Botanical Garden, 1345 Piedmont Ave., NE, Atlanta, GA 30309, USA.
⁴ State Botanical Garden of Georgia, University of Georgia, 2450 Milledge Avenue, Athens, GA 30605, USA.

Abstract

Rhus michauxii is a perennial rhizomatous shrub native to the southeastern United States that is found mainly in sunny, dry, open rocky or sandy woodlands. Moreover, it is found on ridges or river bluffs in the inner coastal plane and lower piedmont of Virginia, Georgia, and the Carolinas. Habitat conversion to agriculture, suppression of fires, and low reproduction have caused R. michauxii to become rare and it is now federally listed as threatened. Methods are needed to multiply and conserve R. michauxii. Protocols were developed for seed cryopreservation, in vitro germination, and micropropagation for R. glabra and R. michauxii. Seed scarification in concentrated sulfuric acid for 6 h and germination on ½ MS medium resulted in germination up to 96% for control and cryopreserved seeds of R. glabra and 70 and 40% for control and cryopreserved seeds of R. michauxii. Shortly after germination in vitro, young seedlings were established in a greenhouse potting mix providing new plants from the endemic Georgia R. michauxii populations. Several of the findings meet goals within the R. michauxii recovery plan by providing methods for sexual and asexual multiplication and long-term seed storage under cryogenic conditions. The protocols developed will assist in the safeguarding and conservation of dwindling natural R. michauxii populations.

Keywords: Michaux’s sumac; Rhus michauxii; conservation; cryopreservation; dwarf sumac; endangered species; false poison sumac; micropropagation; shoot culture.