New Insights on Pollinia Germination and Cryopreservation of a Decalepis arayalpathra - A Critically Endangered Taxon

Abstract

Decalepis arayalpathra, (Apocynaceae s. l.) a critically endangered and narrow endemic taxa confined to Southern Western Ghats, Tamil Nadu and Kerala. The plant has a potential resource for ethno medicinal, phytochemical, economical and biological importance. The present work was assessed on the pollen morphology, cryopreservation (-196°C), pre- and post-in vitro germination studies, under different temperature regimes (-20°C and -80°C) and standardization of germination medium to preserve the pollinia. Each single pollinia consist of 12-22 pollen tetrads. The maximum germination of pollen was achieved in PGM2 15% (Brewbaker-Kwack medium) in absence of potassium nitrate. The results obtained by the process of cryopreservation resulted that the fresh pollen attained 52.86% of germination as compared with those pollen stored under temperature regimes -20°C and -80°C, which literally failed to germinate beyond 2^nd and 5^th day, respectively. However, the germination percentage of cryopreserved pollens was 52% when stored under -196⁰C until 30 days of a month. The present investigation offers the possibility of establishing a pollen preservation protocol for breeding and conservation of this narrow endemic species.