Native forbs are underutilized in ecological restoration, which has negative consequences on species that are dependent on their presence. The most notable affected species are pollinators, especially bees and butterflies, but other species, like the imperiled greater sage grouse, are affected by native forb presence and diversity. Forbs are underutilized because of our limited knowledge about their biology and ecology, which determines how they are propagated and deployed on the landscape.
Currently, eight widespread forb species (or species complexes) have been selected for genetic analyses. Selection criteria for these species were based on:
Tissue collections by Forest Service, Bureau of Land Management and US Fish and Wildlife field crews have been ongoing and DNA sequencing has commenced for three of the forbs, Machaeranthera (Dieteria) canescens, Erigeron speciosus and Crepis accumata. Some selected species are known or suspected to have polyploidy (genome duplication). Polyploidy is relatively common in plants and can strongly affect the growth, physiology, mating compatibility and adaptive capacity. Therefore, known polyploid species are being screened for levels of ploidy (e.g., triploidy, tetraploidy and hexaploidy) using flow cytometry. This technique measures nuclei size from a leaf sample.
DNA sequence data and ploidy information will be used to identify:
Barriers to gene flow can occur from a number of environmental factors including geographic distance, mountain ranges, deserts, presence or absence of pollinator species and ploidy, to name a few. Results from flow cytometry have shown distinct levels of polyploidy in Chaenactis douglasii (Figure 1).
Findings from this research will also be used interpret results from common garden experiments conducted in tandem with this study. Together the genetic data will help inform land managers in collection, seed increase and deployment of native forbs for restoration.