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Simoes-Costa M.C.,Jardim Botanico Tropical | Moura I.R.,Jardim Botanico Tropical | Silva M.J.,Jardim Botanico Tropical | Duarte M.C.,Jardim Botanico Tropical
Acta Horticulturae | Year: 2015

Woodwardia fimbriata Smith is a fern species belonging to the family Blechnaceae. It is native from western North America and known by the common name of giant chain fern. The present study reports Woodwardia fimbriata in vitro spore germination, gametophyte and sporophyte development and subsequent acclimatization of young plants to ex vitro conditions. Spores of W. Fimbriata were obtained by exchange with other botanical gardens (via Index Seminum). Spores were successfully surface sterilized with commercial bleach and germination took place in liquid culture medium, consisting in half-strength Murashige and Skoog mineral salts and 2% sucrose. For sporophyte induction and development, gametophytes were transferred to different semi-solid (0.25% gelrite) culture media, consisting on half-strength Murashige and Skoog mineral salts and 2% sucrose, supplemented with five concentrations of NaH2PO4 (0, 50, 100, 150 and 200 mg/L) or to peat:perlite (1:1) sterile substrate. Two different photon flux density levels were also compared during the process. Best results concerning sporophyte number were observed on peat:perlite substrate (3.92 sporophytes/gametophytic cluster) and 75 μmol/m2/s. Well-developed sporophytes were potted in peat:perlite (1:1) compost and transferred to acclimatization conditions. Survival rates ranged from 90 to 95%. © 2015 ISHS.


Moura I.R.,Jardim Botanico Tropical | Simoes-Costa M.C.,Jardim Botanico Tropical | Silva M.J.,Jardim Botanico Tropical | Duarte M.C.,Jardim Botanico Tropical
Acta Horticulturae | Year: 2015

Ferns are a group of plants particularly vulnerable to threats, largely resulting from their sensivity to environmental disturbances. Herbarium exsiccate are potentially valuable repositories of living spores and may allow the recovery of fern species considered threatened or extinct in the wild. Anogramma leptophylla (L.) Link, Cheilanthes acrostica (Balb.) Tod. And Cosentinia vellea (Aiton) Tod. Subsp. Vellea (Pteridaceae) are hygrophytic (the first) and xerophytic (the last ones) ferns with high ecological value. C. Vellea subsp. Vellea is considered as probably endangered in the archipelago and is included in the Cape Verde Red List. In the present work, spores from six- and eight-year-old exsiccate (LISC Herbarium) of A. Leptophylla and eight-year-old exsiccate of C. Acrostica and C. Vellea, collected in Cape Verde islands, were cultured in vitro. Surface sterilised spores were sown in liquid culture medium consisting on 1/2 strength Murashige and Skoog mineral salts, supplemented with 2% sucrose. Two months after culture initiation well-developed gametophytes were observed in the cultures of the three fern species under study. Only A. Leptophylla eight-year-old spores failed to germinate. Gametophyte development after transfer to different semi-solid media (0.25% gelrite) supplemented or not with 150 mg/L of NaH2PO4 and four different levels of sucrose (0 to 2%) was evaluated. Sucrose content in the culture medium influenced gametophyte growth and proliferation. In terms of sporophyte development, first sporophytes were observed in A. Leptophylla cultures four months after establishment, on medium supplemented with 2% sucrose and 150 mg/L of NaH2PO4. In C. Acrostica cultures, first sporophytes were observed during the fifth month of culture on media supplemented with sucrose and NaH2PO4 while in C. Vellea cultures first sporophytes were only observed after eight months on culture medium devoid of sucrose and on culture medium supplemented with 0.5% sucrose. © 2015 ISHS.

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