Response of spores and young gametophytes of Cyathea delgadii Sternb. (Cyatheaceae) and Blechnum brasiliense Desv. (Blechnaceae) to different light levels

Abstract

Light is a limiting factor for fern stablishment because it controls germination of light sensitive spores. The aim of this work was to study the effect of light levels on spore germination in two ornamental ferns native to the Atlantic forest, under natural conditions. Cyathea delgadii is a tree fern and Blechnum brasiliense, a subarborescent fern. The effect of light levels was analyzed in April and July/2003, in Florianópolis, Santa Catarina state, Brazil. Sterilized spores were sown in Erlenmeyer flasks containing mineral culture medium with macronutrients, iron, and benomyl 0.01%. The Erlenmeyer flasks were kept in 50 cm³ boxes covered with black shade netting, which gave 5, 22, 42, and 62% natural light. Irradiance and temperature were scored daily at 14:00 h during the study period. Higher percentages of germination were observed at 5 and 22% light for both species. Germination of Cyathea delgadii spores at 22% light reached 76% and mean germination time was 19.7 days; at 5% light, germination reached 83.5% and mean germination time was 20.16 days. Germination of Blechnum brasiliense at 22% light reached 76% and mean germination time was 9.06 days; at 5% light, germination reached 84% and mean germination time was 13.18 days. The highest light levels inhibited spore germination and the gametophytes died during the test period.

Somatic embryogenesis in ferns: a new experimental system

“…can be cut, transported and replanted, and can still continue to grow, as long as the crown remains intact (FPA Biodiversity Program 2012 ). Over the last few years, the propagation of tree fern species from spores has become the priority area for ex situ conservation studies (Simabukuro et al 1998a , b ; Arens 2001 ; Hiendlmeyer and Randi 2007 ; Rechenmacher et al 2010 ; Ranil et al 2011 ; Martíez et al 2014 ). Conversely, methods of in vitro culture have been exploited for the propagation of tree ferns by gametophyte multiplication and sporophyte regeneration.…”

Spore Germination of Three Tree Fern Species in Response to Light, Water Potential, and Canopy Openness

“…and the tree fern Cyathea delgadii Sternb. in a subtropical rainforest in Brazil (Brum and Randi, 2002;Hiendlmeyer and Randi, 2007). A study on the spore germination of five tree-fern species from subtropical forests in Mexico showed a strong relationship between species distribution and their temperature tolerance (Pérez-García and Riba, 1982).…”

“…In angiosperms, it was found that interspecific competition may be reduced when seeds germinate in conditions associated with the habitat where the species grows, and with this, the coexistence of species in tropical forests is favored (Daws et al, 2002;Pearson et al, 2003). It has been demonstrated that recruitment differs among some fern species, and that terrestrial fern species colonization and distribution could depend on micro-habitat availability, plant competition and life history attributes (De Groot et al, 2012;Flinn, 2007;Hiendlmeyer and Randi, 2007;Peck et al, 1990;Testo and Watkins, 2013;Watkins et al, 2007).…”

Do fern gametophytes have the capacity for irradiance acclimation?

“…It has been demonstrated that PFD affects the germination of spores (Hiendlmeyer and Randi 2007) and density of terrestrial gametophytes (Watkins et al 2007b). However, photosynthetic responses to PFD remained to be established.…”