Cryopreservation of excised embryonic axes of <i>Nothapodytes nimmoniana</i> (Graham) Mebberly—A vulnerable medicinal tree species of the Western Ghats

Abstract

435-437Desiccation sensitivity and freezing tolerance of excised embryonic axes from the seeds of Nothapodytes nimmoniana (Graham) Mebberly and their cryopreservation were examined. Zygotic embryos with cotyledons excised from fully ripened fruits possessed 55.7% moisture content (MC) and 86.67% of them germinated in Murashige and Skoog (MS) medium devoid of plant growth regulators (PGR). Dehydration under laminar airflow for 120 min reduced the MC of the embryos to 19.6% and germination to 68%. Subsequent reduction in MC to 15.4, 14.2 and 12.1% also reduced the germination. Embryos dehydrated for 120 min after 1-wk-storage in Liquid nitrogen (LN) showed 60% germination, which was the optimum condition obtained in the study. The LN treated embryos developed into healthy seedlings after 30-60 d of inoculation in MS basal medium similar to desiccated control. Prolonged desiccation damaged the plumule where only root formation was observed. The study reveals the possibility of long term ex situ conservation of N. nimmoniana, which produces large and intermediate type of seeds, through zygotic embryo cryopreservation