In vitro Spore Germination, Gametophyte Development, and Reproductive Biology of Pteris vittata L.

Abstract

Aims: This study investigated the reproductive biology of Pteris vittata L. under in vitro conditions, focusing on spore morphology, germination, gametophyte development, gametangial differentiation, and sporophyte formation. Study Design: An experimental in vitro culture study. Place and Duration of Study: Department of Botany, G. M. Momin Women’s College, Bhiwandi, Thane, Maharashtra, India. The study involved laboratory culture and periodic observation of spore germination and reproductive development. Methodology: Fertile fronds of Pteris vittata L. were collected from naturally growing sporophytes in Maharashtra, India. Spores were collected, stored at 4 °C, and surface-sterilised with 2% sodium hypochlorite for 2 min. Sterilised spores were cultured on modified Knop’s medium supplemented with Nitsch’s trace elements. Cultures were maintained at 25 ± 2 °C under a 16 h light/8 h dark photoperiod. Spore germination, gametophyte development, and gametangial differentiation were periodically observed microscopically. Results: Sporangia contained 64 spores per sporangium. The spores were brown, tetrahedral, and trilete. Spore germination was observed 4 days after inoculation on modified Knop’s medium. Spore germination followed the Vittaria type, whereas gametophyte development followed the Ceratopteris type. Germination commenced 4 days after inoculation, followed by the formation of a uniseriate germ filament with 3–4 chlorophyllous cells by 7 days. Two-dimensional growth began at 10–12 days. Gametophytes progressed through spatulate, lopsided, semi-cordate, and mature cordate stages, reaching maturity by 45 days. Antheridia appeared at 46 days and archegonia at 51 days. Sporophytes appeared at 90 days in the composite population and 110 days in the isolated population. Conclusion: In vitro spore culture on modified Knop’s medium supplemented with Nitsch’s trace elements supported progressive reproductive development of P. vittata from spore germination through gametophyte maturation and early sporophyte formation.