Provenance and ecotype may be important in the selection of plants for use in habitat restoration projects. Asclepias syricaca (Common Milkweed), has a widely distributed ecotype, concentrating mostly in eastern regions North America. The concern of planting seeds of different ecotypes has risen. Scientists have indicated that doing this may induce hybridization and cause the loss of genetic diversity. This would cause the loss of successful reproduction in these specific environments.
For Common Milkweed to be used as habitat restoration, the establishment of productive propagation methods is necessary. It has been speculated that a longer, cold stratification period will break the seeds dormancy and prove productive. This idea has been generated due to the knowledge of the provenance of this plant in colder regions. The question is whether the widely distributed ecotypes of this plant will affect this propagation strategy and production. It is believed that a successful propagation, determined by average number of days until germination, percent germination, and measured growth, will be obtained with a longer cold stratification of seeds.
Asclepias syricaca seeds of three different ecotypes were obtained and weighed to determine seed mass. 10 seeds from each ecotype were stratified in petri dishes and 24 seeds from each ecotype stratified in soil. Moist stratification at room temperature and cold stratifications of 10 and 30 days were performed. After germination seeds in the soil will be allowed to grow for 30 and 60 says. Growth will then be determined by height, leaf density and biomass. Biochemical assay will be used to determine the amount of chloroplast produced at each level of stratification. PCR and electrophoresis will be used to determine genetic variation among ecotypes. An ANOVA will be performed to determine whether seed mass is variable between ecotypes.
Results/Conclusions
Seed mass of all seeds in each ecotype were calculated and an ANOVA was run to determine variability between ecotypes. The seeds from the three different ecotypes were shown to be significantly different in seed mass. After the maximum germination period of 14 days, the seeds in the petri dishes and soil in a moist room temperature environment did not germinate at room temperature. The results of this study indicate that seed mass may be a contributor to the productive propagation, of seeds of different ecotypes, in different environments, and the absence of germination without cold stratification indicate cold stratification may be needed for a productive yield.