Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China

Abstract

Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum, in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum) did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44%) with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35%) at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae.

Co-Cultures of Mycorrhizal Fungi Do Not Increase Germination and Seedling Development in the Epiphytic Orchid Dendrobium nobile

“…Orchids associating with a limited number of fungi or with fungi that have a restricted distribution (Waud et al, 2016) can be expected to have narrower distribution patterns compared to orchids that associate with a large number of fungi or with fungi that have a broad distribution (Davis et al, 2015;Těšitelová et al, 2015). Better insights into the relationships between orchid seeds and associated fungi may therefore improve our understanding of the various factors that determine the geographic distribution of orchid species and at the same time benefit symbiotic seedling propagation for in situ and ex situ conservation and reintroduction programs (Fracchia et al, 2014(Fracchia et al, , 2016Shao et al, 2017;Decruse et al, 2018).…”

Establishment of a Rapid Breeding System for Bletilla Striata

“…The growth and development of plants have their own inherent genetic patterns and sequences. In certain ambient environments, external materials and energy are employed for the proliferation and differentiation of plants (Shao et al 2017). In the process of development, the aboveground and underground plant components have a direct mutual promotion relationship, therefore, the evaluation of the health of a plant's growth largely depends on the development of its root system.…”

A Proposed Framework for Efficient and Cost-Effective Terrestrial Orchid Conservation

“…Seed germination in situ can also be increased by fungal inoculation (Batty et al 2006b). In situ seed germination on tree bark also works for tropical epiphytic orchids using pouches of fungus-inoculated peat moss (Shao et al 2017).…”