Spore germination, early development and some notes on the effects of in vitro culture medium on Frullania ericoides (Nees) Mont. (Frullaniaceae, Marchantiophyta)

Juliana Da Costa Silva-E-Costa,Cristiano Ferrara De Resende,Andrea Pereira Luizi-Ponzo,Paulo Henrique Pereira Peixoto

doi:10.1590/0102-33062016abb0336

Juliana Da Costa Silva-E-Costa, Cristiano Ferrara De Resende + Show 2 more

Open Access

https://doi.org/10.1590/0102-33062016abb0336

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Abstract

In bryophytes, establishment can occur by a sexual or asexual process, but the production of spores enables colonization of a wider range of habitats and substrates than can asexual propagules. Successful germination is critical for establishment in a new environment. This paper addresses germination and sporeling development in Frullania ericoides, a leafy liverwort species. Fresh spores were inoculated in vitro in different culture strengths of Knop’s nutrient solution (one-fourth strength, half strength, full strength, one and a half strength and double strength), in order to evaluate the effects of this solution on spore germination and on the development of external protonema. On the first assessment, spore germination was observed at all the concentrations. Germination was endosporic, with cell division and proliferation, resulting in a globular protonema, within the spore wall. Beginning at the fourth week, the development of tightly concave primordial leaves was observed in all but the double-strength medium. Throughout the period of study, the treatments with lower concentrations exhibited external protonema with greater lengths. The double-strength treatment was statistically different from other treatments in at least two parameters. The results of this study demonstrate the potential of in vitro culture techniques for bryophyte spore studies and germplasm preservation.

Highlights

Bryophytes are non-lignified cryptogamic plants that have a life cycle with alternating heteromorphic generations in which the gametophyte is the dominant phase (Gradstein et al 2001; Gradstein & Costa 2003; Goffinet et al 2009; Vanderpoorten & Goffinet 2009)
In view of the wide distribution of the species F. ericoides, ecological features and the scarcity of palynological and physiological studies concerning this species; and further the lack of studies to evaluate different concentrations of the same culture medium, our work aims to (1) describe the spore germination morphology, detailing phases of in vitro protonema development of Frullania ericoides and (2) evaluate the response of growth on different strength of culture media, based on a medium already used in the literature
In the first week of the analysis, there was development of a globular and multicellular protonema enclosed in the spore wall that expanded without cracking, a typical endosporic germination (Fig. 1A-L, 2A-H)

Summary

Introduction

Bryophytes are non-lignified cryptogamic plants that have a life cycle with alternating heteromorphic generations in which the gametophyte is the dominant phase (Gradstein et al 2001; Gradstein & Costa 2003; Goffinet et al 2009; Vanderpoorten & Goffinet 2009). The sporophyte, perennial, is responsible for the production of spores, which are considered the first cell of gametophytic stage (Schofield 1985) This reproduction by producing spores enables the colonization of new substrates through dispersal mainly by wind (Zanten & Pócs 1981; Longton & Schuster 1983; Wiklund & Rydin 2004; Longton 2006; Glime 2007). In order for establishment in a new environment to be effective, a successful spore germination processes is fundamental (Glime 2007)

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