Long-term Conservation Through Cryopreservation of Immature Seed of Mantisia Spathulata and Mantisia Wengeri; Two Endangered Plants of North-East India

A successful protocol for long-term conservation of two endangered plants viz. Mantisia spathulata and M. wengeri has been devised through cryopreservation of immature seeds. Immature seeds of both the species were precultured in 0.6 M Sucrose and 2 M Glycerol for 3 h at 24 ± 2ºC. Precultured seeds were then desiccated under the airflow of 27 ± 3 m min^-1 velocity inside laminar air flow cabinet for different time periods. The seeds were then cryostored in liquid nitrogen for an hour. A maximum of 40% and 36.6% seed germination was recorded after cryostorage at moisture contents of 26.0% and 16.2% for M. spathulata and M. wengeri respectively. To protect these rare plants against loss due to disease, insect damage, or natural disaster a back up collection has been established using the protocol and applied to a large number of immature seeds that were obtained from the ex situ plants growing in the experimental garden of the North-eastern Hill University, Shillong.