The Role of Micropropagation In Hawaiian Plant Conservation

The diversity of native plant life within the Hawaiian Archipelago represents some of the most unique examples of insular evolution in the world. Hawaii’s native plant taxa represent a full one-third (303 of which 7 are extinct) of the nation’s federally listed endangered and threatened plants.  Another 268 unlisted taxa are presently in rapid decline and considered critically “at risk” of extinction. On the international level, over 200 of Hawaii’s native taxa are registered on the International Union for Conservation of Nature (IUCN) Red List, which provides information on taxa that are facing a high risk of global extinction. Since 1992, Lyon Arboretum’s research emphasis on conservation biology has led to the development of the Hawaiian Rare Plant Program (HRPP), which focuses on the rescue and recovery of Hawaii’s most critically endangered plants.  

The HRPP assists in the prevention of further extinction by providing a cooperatively administered, fully integrated ex situ plant recovery system, which works in tangent with Hawaii’s inter situ and in situ management programs. The HRPP’s ex situ activities complement statewide in situ plant conservation, by assisting in the augmentation of plant stocks for reintroduction and by maintaining onsite a genetically diverse germplasm bank composed of more than 11,300 in vitro cultures consisting of 218 native plant taxa.  Each year, the HRPP receives approximately 560 plant submissions of about 135 native Hawaiian species annually. To date, our in vitro laboratory and greenhouse facility has successfully grown more than 300 (136 federally endangered or threatened) of the 1400+ native Hawaiian plant taxa, through micropropagation and conventional horticultural methods.

Plant micropropagation has become an indispensable tool for plant genetic conservation especially where conventional propagation efforts have failed or proven to be difficult. Micropropagation is particularly useful in situations where seed propagules are collected immature, small, recalcitrant, or are rare. The seeds are germinated in vitro and stored as living germplasm collections or prepared for future restoration projects. When seed are unavailable, clonal propagules can be initiated, propagated, and maintained in vitro. The HRPP is the only facility of its kind in the State of Hawaii and holds Hawaii’s largest and most diverse collection of native Hawaiian plant taxa. Due to its propagation and germplasm banking specialization, the HRPP plays a critical role in the conservation and recovery of one of the most fragile floras in the world.