2019 ASHS Annual Conference

There is a growing demand for sustainable horticultural crops, and more specifically, drought -tolerant native plants. However, some native plants are difficult to cultivate due to lack of seed availability, poor quality or expensive seed, lack of propagation knowledge and hard-to-propagate seed properties. Sphaeralcea coccinea is native to arid regions of the Western United States and Canada and has many valuable characteristics as a horticultural crop, but it is a hard-to-propagate species due to its hard seed coat and impermeable substances within the seed. Plant tissue culture technology, specifically in vitro embryo culture, is an effective method to quickly break seed dormancy and provide plantlets for transplant to soil and growth to maturity. For this study we evaluated the effect of MS media modified with five levels of gibberellic acid (GA) (1µm, 2µm, 4µm, 8µm, and 16µm) on S. coccinea embryos. Seeds were first subjected to a 40 minute sulfuric acid (18M) soak to dissolve the seed coat for dissection and excision of the embryo under sterile conditions. Excised embryos were transferred to petri dishes containing sterile MS media (control) and MS modified with sterile filtered GA. Petri dishes were maintained at 24+/-1 °C in the dark. Germination was judged by radical expansion of 2mm in length and recorded daily for 7 days. It is hypothesized that increasing rates of GA will lead to increased germination rates.