In vitro spore germination of Pityrogramma calomelanos - A medicinal fern

Ferns have a great economic value based upon the good ornamental qualities of foliage. Pityrogramma calomelanos (L.) Link. commonly known as ‘Silver fern’, belongs to the family Pteridaceae and is a terrestrial or lithophytic herbaceous fern distributed in the tropical and subtropical regions of the world. It is a medicinally important ornamental fern. The spore germination and developmental pattern of prothallium has been dealt herein with particular emphasis on gametophyte, emergence of antheridia as well as archegonia, their fertilization and turnover of sporophytes. The spores started germinating just after 5 days, whereas thespores sown after 25 days in the similar composition of culture media did not show any germination, emancipating full loss of spore viability. The study of this medicinal fern includes spore germination, gametophyte growth, differentiation sex ontogeny and development of sporophytes. The effect of kinetin and IBA with KC media yielding a high number of sporophyte formations. In addition to the normal turnover of sporophytes in above sets of experiment, it was also observed that the dense spore sowing developed usually small, uniseriate, very occasionally broadened, abnormal gametophytes rather than normal cordate one, which always failed to produce any sporophyte. In vitro raised plants showed 54% of establishment during hardening in the field. The present study has established the reproducible protocol for the ex situ conservation of this Medicinal fern.