Storage and in vitro germination of orchids (Orchidaceae) seeds from Atlantic Forest - Brazil.

Cristina R.B Franceschi,Eric C Smidt,Leila N Vieira,Luciana L.F Ribas

doi:10.1590/0001-3765201920180439

Cristina R.B Franceschi, Eric C Smidt + Show 2 more

Open Access

https://doi.org/10.1590/0001-3765201920180439

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Abstract

The orchid seed banks of Atlantic Forest may be considered a key strategy for the conservation of species threatened with extinction by indiscriminate collection or habitat destruction. The aim of this study was to evaluate the seed viability, to choose the best culture medium for the asymbiotic germination and evaluate germination, after storage for different periods and temperatures for the Brazilian native orchids: Gomesa praetexta (Rchb.f.) M.W.Chase & N.H.Williams, Gomesa forbesii (Hook.) M.W.Chase & N.H.Williams, Gomesa recurva R.Br. and Grandiphyllum divaricatum (Lindl.) Docha Neto. Knudson C (KC), Murashige & Skoog (MS), half-strength MS (1/2 MS macro- and micro-nutrients) and Woody Plant Medium (WPM) culture media were tested for germination. The WPM culture medium was the best for asymbiotic germination of all species evaluated, with high germination percentages and improved seedling development. Seeds of G. divaricatum, G. praetexta, G. recurva and G. forbesii indicated orthodox behavior, with high viability rates after 12 months of storage, being recommended the storage temperature of -80°C for the first three species and -20°C for G. forbesii. The protocol developed in the present study was efficient for seed bank storage, in vitro germination and seedling production of G. divaricatum and G. praetexta, contributing to conservation strategies of these species.

Highlights

Orchidaceae is one of largest and most species-rich families of flowering plants, their habitats are threatened throughout the world (IUCN/SSC Orchid Specialist Group 1996, Fay 2016)
We evaluated the seed viability and asymbiotic germination of four Brazilian native orchids, Gomesa praetexta, Gomesa forbesii, Gomesa recurva and Grandiphyllum divaricatum, after storage for different periods and at two temperatures, in order to establish a seed bank
Plants of G. recurva and G. forbesii were cultivated in the greenhouse “Frederico Carlos Hoehne” at the Institute of Botany, São Paulo, Brazil, and plants of G. divaricatum and G. praetexta were cultivated in the greenhouse of Departamento de Botânica da Universidade Federal do Paraná, Paraná, Brazil

Summary

Introduction

Orchidaceae is one of largest and most species-rich families of flowering plants, their habitats are threatened throughout the world (IUCN/SSC Orchid Specialist Group 1996, Fay 2016). STORAGE AND in vitro GERMINATION OF ORCHIDS SEEDS lead to over-collection for economic purposes, a serious threat to many orchid species. This current state of conservation requires the development of integrated conservation approaches, such as ecological and genetic studies, and in situ and ex situ conservation (Swarts and Dixon 2009). In many species of the Orchidaceae family, seeds tolerate dry storage at -20°C (Seaton et al 2010). Orchid seed banks may be considered a key strategy for the conservation of valuable genetic resources and possible further re-introduction into the original habitat (Seaton et al 2010)

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