Seed Cryopreservation, Germination, and Micropropagation of Eastern Turkeybeard, Xerophyllum asphodeloides (L.) Nutt.: A Threatened Species from the Southeastern United States

Abstract

Xerophyllum asphodeloides (Xerophyllaceae), known as eastern turkeybeard, is an herbaceous perennial found in eastern North America. Due to decline and destruction of its habitat, several states rank X. asphodeloides as “Imperiled” to “Critically Imperiled”. Protocols for seed cryopreservation, in vitro germination, sustainable shoot micropropagation, shoot establishment in soil, and seed germination are presented. Seeds from two tested sources were viable after 20 months of cryopreservation. Germination of isolated embryos in vitro was necessary to overcome strong seed dormancy. Shoot multiplication and elongation occurred on ½ MS medium without PGRs. Shoots rooted in vitro without PGRs or with 0.5 mg/L NAA or after NAA rooting powder treatment and placement in potting mix. When planted in wet, peaty soil mixes, shoots grew for two months and then declined. When planted in a drier planting mix containing aged bark, most plants continued growth. In the field, plant survival was 73% after three growing seasons. Safeguarding this species both ex situ and in situ is possible and offers a successful approach to conservation. Whole seeds germinated after double dormancy was overcome by incubation under warm moist conditions for 12 weeks followed by 12 weeks cold at 4 °C and then warm.

Seed Maturity and Its In Vitro Initiation of Chilean Endemic Geophyte Alstroemeriapelegrina L.

“…In addition, in vitro culture helps maintain genetic variability, reducing genetic bottlenecks and increasing the adaptability of populations, which maintains diversity, reduces the risk of species extinction, and, thus, ensures the success of ex situ conservation efforts [26,27]. Micropropagation has been used successfully for a variety of species, from ornamentals to forest trees, as it produces homogeneous seedlings under sterile conditions.…”

“…At the same time, methods using seed-grown explants have been overlooked, even though they are equally useful for the genetic improvement of species and commercial breeding [25]. The benefits of in vitro seed cultivation include higher germination percentages, a reduced time, and a uniform germination of species with dormancy problems [26]. In addition, seedlings for micropropagation are available quickly, contributing to the conservation of the natural genetic diversity of vulnerable species.…”

“…The seedlings can be used to enhance existing populations of vulnerable species or to establish new cultivation sites for conservation or research purposes. Ex situ breeding experiments at such sites will, therefore, not affect the genetic diversity of plant populations in their natural habitats or reduce their evolutionary potential [26,27].…”

Seed Longevity—The Evolution of Knowledge and a Conceptual Framework

“…In fact, orthodox seeds’ ability to survive storage is the lynchpin in global efforts to conserve plant genetic resources as seeds. The term ‘recalcitrant’ is also used in a horticultural sense to describe seeds that typically exhibit low germination because they have complex requirements for hydration/dehydration and temperature fluctuations before radicles emerge [ 39 , 40 , 41 , 42 , 43 ].…”

Cryopreservation of bioflavonoid-rich plant sources and bioflavonoid-microcapsules: emerging technologies for preserving bioactivity and enhancing nutraceutical applications

“…one can look at an article written by Zamecnik et al(14) for a better understanding of PVS. The solutions come into contact with the cell and then form PVS solute compounds changing the glass transition temperature, and/or with the bound water, which hinders the intercellular ice crystals-formation(14,(96)(97)(98)(99).…”