Biological and nutritional aspects involved in fern multiplication

Gametophytes of several species of ferns were mechanically triturated and t he resulting homogenates cultured in vitro for propagation purposes. Differ ences in the time period from spore culture to sporophyte development were perceivable between species. For those species with a fast life cycle and h igh sporophyte production such as Woodwardia virginica and Dryopteris affin is sp. affinis, homogenization of gametophytes can be considered to be exce llent method for propagation, yielding hundreds of sporophytes in a short p eriod of time. Sporophyte formation was inhibited in O. regalis by the succ esive application of homogenization to gametophytes regenerated by this tec hnique. The effect of the culture medium composition on fern production was also studied in O. regalis and P. ensiformis gametophytes. In these specie s, sporophyte formation increased when the gametophytes were cultured in a medium containing water+0.7% agar. Addition of sucrose inhibited gametophyt e development and induced their necrosis. The 1/2 dilution of Murashige and Skoog basal medium, without sucrose, favoured leaf expansion in P. ensifor mis sporophytes.