The genetics of restoration: A reciprocal transplant experiment with winterfat (Krascheninnikovia lanata)

Local adaptation and outbreeding depression are factors that could affect the success of revegetation projects. The source of seed used to plant a restoration site may affect project success because seeds are best adapted to the area from which they were collected. Seed planted in distant locales may not germinate or flower at the correct time, thus leading to decreased survival and seed set, which would reduce the vegetative recovery of the site. In addition, such maladapted individuals may interbreed with locally-adapted individuals, eventually reducing the mean population fitness (outbreeding depression). Little is known about how far seeds can be planted from their collection source before exhibiting reduced vigor. I have set up a reciprocal transplant experiment in New Mexico using winterfat (Krascheninnikovia lanata, Chenopodiaceae) as the study species. 13,824 seeds (6 sites x 3 plots per site x 24 maternal families per plot x 8 replicates per family x 4 seeds per pot) were sown in the greenhouse in January 2006. Origin of the seed had a significant effect on time to germination and time to flowering. Approximately 2,600 of these seeds were grown to plants that were reciprocally transplanted between sites. Individuals originating from a site have the highest survival and growth at that site. Source population also affects flowering time. These results indicate the potential for local adaptation effects on revegetation with winterfat. Further experiments will explore the role of outbreeding depression.