Hard seed: the effects of seed scarification on germination rate in Callirhoe bushii (Bush's poppy mallow).

Chevalier, Cary

Callirhoe bushii, Bush's poppy mallow, is ranked as $2 (imperiled in the state because of rarity or because of some factor making it vulnerable to extirpation from the state) by the Missouri Department of Conservation. Previous propagation attempts have shown C. bushii seeds to germinate over long periods of time. In order to ensure the existence of C. bushii populations in Missouri, a reliable ex situ protocol for propagating the seeds is necessary. The effects of seed scarification techniques on germination rate in C. bushii were examined in this experiment. Three methods of scarification were tested in an attempt to break the physical dormancy of C. bushii seeds: wet heat, razor blade cut, and combined razor blade cut with a wet heat soak. Seeds in each of the treatment groups and a control group germinated. Treatment appears to have no significant effect on germination rate. Germinations continued to occur over 307 days from the time of sowing. Our results suggest that C. bushii seeds may have both physiological and physical dormancy.

* Gosejohan, M.C. and K.A. McCue. Department of Biology, University of Missouri-St. Louis and Missouri Botanical Garden.