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- In vitro minimum growth for conservation of Drosophyllum lusitanicumPublication . Gonçalves, Sandra; Romano, AnabelaThe present paper reports a protocol for minimum growth conservation of Drosophyllum lusitanicum (L.) Link. in vitro. Double-node cuttings were maintained for 4, 8 and 12 months at 5 or 25 ºC in the dark. The effects of sucrose either alone at 5, 20, 30, 40 and 60 g dm-3 or at 20, 40 and 60 g dm-3 in combination with 20 g dm-3 mannitol, on survival and post-storage shoot multiplication efficiency were investigated. The cultures could effectively be conserved under minimum growth at 5 ºC for 8 months on Murashige and Skoog’s medium supplemented with 60 g dm-3 sucrose, 20 g dm-3 mannitol and 0.91 μM zeatin. Following extended conservation, the cultures could be successfully regenerated into new shoots, and they were morphologically similar to those of non-stored controls.
- Micropropagation of Drosophyllum lusitanicum (Dewy pine), an endangered West Mediterranean endemic insectivorous plantPublication . Gonçalves, Sandra; Romano, AnabelaIn this work, in vitro clonal propagation of Drosophyllum lusitanicum (Dewy pine) was obtained from seedlings germinated in vitro. Seeds were collected in various populations identified in the Algarve region and germinated in vitro on MS medium supplemented with 0.5 mg l 1 BA (6-benzyladenine) and 0.1 mg l 1 GA3 (gibberellic acid). The obtained shoots were used in several multiplication assays. The best results were observed in MS medium supplemented with 0.2 or 0.5 mg l 1 zeatin. The highest rooting frequency (83%) was observed on 1/4MS medium supplemented with 0.2 mg l 1 IBA (indole-3-butyric acid). Fifty percent of the plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. Plans are underway to reintroduce the in vitro produced plants from this study in selected locations in their natural habitat.
- In vitro micropropagation of endangered Rhododendron ponticum L. subsp. baeticum (Boissier & Reuter) Handel-MazzettiPublication . Almeida, Rosália; Gonçalves, Sandra; Romano, AnabelaIn vitro propagation of Rhododendron ponticum L. subsp. baeticum, an endangered species present in limited and vulnerable populations as a Tertiary relict in the southern Iberian Peninsula, was attained. Several cytokinin:IAA ratios and a range of zeatin concentrations were evaluated for their effect on shoot multiplication from apical shoots and nodal segments. The type of cytokinin and the origin of the explant were the most important factors affecting shoot multiplication. The highest shoot multiplication rate was obtained from single-nodal explants on medium supplemented with zeatin. Increasing zeatin concentration promotes shoot multiplication independently of explant type, although this effect tends to decrease with higher zeatin concentration. Shoot growth was higher in apical shoots and it was not stimulated by the presence of auxin. A number of experiments were conducted to identify suitable procedures for rooting of in vitro produced shoots. The best results in terms of in vitro rooting were obtained with Anderson’s modified medium with macrosalts reduced to one-half, regardless of the auxin or its concentration in the medium. Although rooting frequency rose to 97% by basal immersion of shoots in auxin concentrated solution followed by in vitro culture on an auxin-free medium, the survival of the plants after 6 months of acclimatization was poor (50%). Best results (100% rooting and survival) were observed for ex vitro rooting. The micropropagated plants from this study were successfully reintroduced into their natural habitat (87% of survival after 8 months).