<i style="">In vitro</i> developmental ontogeny and life cycle of a rare fern species— <i style="">Thelypteris confluens </i>(Thunb.) Morton

Abstract

The conservation of <i style="">Thelypteris confluens</i>, which was under the list of rare and endangered ferns of Western Ghats of South India, is the major concern of this work. The <i style="">in vitro</i> life cycle starting from spore germination, followed by micromorphological changes and the reproductive biology with regard to the monocultures of this species was thoroughly studied in simple medium. The fern showed specific germination and growth pattern of <i style="">Vittaria</i> and <i style="">Drynaria </i>type. Sex organs in male, female and hermaphroditic gametophytes underwent fertilization and the sporophytes developed with sprouting leaves within 120 d in the cultures. Harderning and acclimatization procedures responded very well to the sea level as well as to high altitudes of 1800-2400 m and proved to be having a very good propagating potential with regard to spore culture. The regeneration of miniature gametophytes from the old male prothalli as filamentous structures indicates the autotrophy and rejuvenating potential of this species. Results of micromorphology, gender analysis and reproductive potential justify the rarity of this species.