Harper’s Beauty (Harperocallis flava) seed biology and micropropagation

Wet prairies, bogs, and upland-wetland ecotonal habitats in the Florida panhandle have been widely degraded due to fire suppression. Fire suppression promotes establishment of a dense, shrubby midstory, primarily composed of swamp titi (Cyrilla racemiflora), and may also limit the availability of nutrients, light, and microsites for germination of native plants. The first steps in restoring these habitats are the reduction of shrub encroachment and reintroduction of frequent fire. Even where these steps are successful, though, not all native species are able to recolonize restored sites naturally. One such species is Harperocallis flava (Harper’s Beauty) a federally endangered plant endemic to terrestrial wetlands in the Florida panhandle. A narrow distribution, low genetic diversity, habitat loss and degradation, the threat of road construction, and climate change put H. flava’s existence at risk. This research is part of a collaborative project with the University of Florida investigating seed biology and laboratory propagation of H. flava to support Federal species recovery objectives. The information gained from this endeavor will not only benefit Harperocallis flava but will help develop and refine propagation and restoration techniques that can be applied to other species and ecosystems that are priorities for FWC.

Previous work suggests that low seedling recruitment may be limiting population growth of H. flava, and it is unlikely that introducing a shorter fire return interval alone will be enough for H. flava populations to rebound without further interventions. An in-situ seedling emergence study showed low seedling emergence and extremely low survival after 6 months, suggesting that direct seeding of H. flava may not be feasible to establish additional colonies and augment populations. However, seed based micropropagation (clonal, in vitro propagation of plants from seed) may be an effective tool to accomplish recovery goals. With this research, we are examining the feasibility of micropropagation techniques to assist with the U.S. Fish & Wildlife Service’s H. flava recovery objectives. Federal recovery plans emphasize using seeds for conservation, as reflected in H. flava recovery objectives 3-5: preserving germplasm; establishing additional colonies; and monitoring and managing populations to aid in recovery.

Micropropagation of plants from seed serves to advance ex situ plant production for later reintroduction. A significant need exists to examine new seed-based micropropagation techniques for creation of additional H. flava colonies. This project focuses on two objectives: 1) examining greenhouse acclimatization of micropropagated plantlets – monitoring growth and survivorship of H. flava plants grown from genotypes produced via in vitro; and 2) assessing reintroduction potential of micropropagated plantlets into their native populations– monitoring growth, development, and survivorship of H. flava plants transplanted into the natural habitat for 6-8 months post planting. Within the 9-month project timeframe, we will produce: 1) a micropropagation protocol for Stages I through IV (greenhouse acclimatization); 2) a protocol for the reintroduction of micropropagated plants to the native habitat; and 3) a new understanding of how genotype influences methods for production of additional colonies.