Sporophyte induction studies in ferns in vitro

Sporophytes induction from spore-derived gametophytes and the morphogenic potential of homogenised sporophytes were performed in several ferns: Adiantum capillus-veneris, Asplenium adiantum-nigrum, Ceterach officinarum, Davallia canariensis, Dicksonia antarctica, Dryopteris dilatata, Dryopteris filix-mas, and Polypodium cambricum. The influence of growth rate, the formation of sexual organs, and the homogenisation of the gametophyte on sporophyte formation were studied. Gametophytic growth and sporophyte development were not antagonistic events and no correlation was found between the proportion of sexual phenotypes and rate of sporophyte formation. A pre-treatment of the rhizome with BAP exhibited swelling and upon transferral to Murashige and Skoog (MS) basal medium developed numerous fronds. Homogenised sporophytes of A. capillus-veneris, D. canariensis, and P. cambricum cultured on MS basal medium regenerated sporophytes while on MS with 4.4 μM BAP favoured formation of aposporous gametophytes and/or dedifferentiated cellular aggregates. In A. adiantum-nigrum, BAP induced either aposporous gametophytes or sporophytes.