In Vitro and Cryobiotechnology Approaches to Safeguard Lupinus rivularis Douglas ex Lindl., an Endangered Plant in Canada

Conservation of threatened flora in genetic collections ex situ using in vitro culture and cryopreservation is receiving an increasing recognition as a complementary strategy to in situ conservation in natural habitats. The present study is focused on an integrated approach which involves conservation and propagation, emphasizing the usefulness of cryopreservation techniques for germplasm conservation of streambank lupine (Lupinus rivularis Douglas ex Lindl.), an endangered species in Canada. This included in vitro seed germination on Murashige and Skoog basal medium supplemented with 1 µM thidiazuron to induce multiple shoot formation, micropropagation on a medium with 5 µM benzylaminopurine, and in vitro rooting on medium with 20.0 µM indole-3-butyric acid. Cryopreservation of seeds and shoot tips of in vitro grown plants was successful with over 60% seed germination and 62% regrowth of cryopreserved shoot tips, respectively. Plants developed from cryopreserved seeds had chlorophyll contents in leaves and the growth characteristics including the development of inflorescence, similar to plants raised from non-cryopreserved seeds. These results provide further evidence that the combination of micropropagation with cryopreservation of seeds and vegetative parts may effectively facilitate long-term preservation of L. rivularis and other endangered species.