Micropropagation of the endangered shrub pondberry (Lindera melissifolia [Walt.] Blume)
A micropropagation protocol using shoot cultures is described for Lindera melissifolia, a federally listed endangered shrub endemic to the southeastern United States. Stock plants were harvested from native L. melissifolia populations growing in the lower Mississippi Alluvial Valley. In vitro proliferation was on woody plant medium supplemented with 1 um zeatin. After 6 weeks, zeatin level was increased to 5 um. Treatment of micropropagated shoots with a liquid auxin (2 indole-3-butyric acid : 1 1- naphthalenacetic acid) resulted in a low mean rooting percentage (144%) compared with rooting in the absence of auxins and on a pure peat medium ex vitro, which increased rooting to 280%. Time to rooting was 8 weeks. Plants were acclimatized for 2 weeks, then potted in a 2 peat : 1 perlite medium supplemented with superphosphate, 10N-10P-10K, and Milorganite. Micropropagated L. melissifolia stecklings have been successfully outplanted in both controlled and field studies at the Center for Bottomland Hardwoods Research (Stoneville, Miss.).