Location: Forage and Range ResearchTitle: The merits of artificial selection for the development of restoration-ready plant materials of native perennial grasses
|CHIVERS, I - Australian National University|
|BROADHURST, LINDA - Commonwealth Scientific And Industrial Research Organisation (CSIRO)|
Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2015
Publication Date: 3/1/2016
Citation: Chivers, I.H., Jones, T.A., Broadhurst, L.M., Larson, S.R., Mott, I.W. 2016. The merits of artificial selection for the development of restoration-ready plant materials of native perennial grasses. Restoration Ecology. 24:174-183.
Interpretive Summary: As the building blocks of ecological restoration, plant materials must be increasingly effective in establishing and persisting in challenging restoration environments. Artificial selection of plant materials for critical functional traits is one way to increase their efficacy. Because plant materials offered by a seed industry are subject to the market forces of supply and demand, successful plant materials provide economic incentives to both seed growers and restoration practitioners. Only plant materials that are both adapted to the challenging restoration environments where they will be used and display favorable economic characteristics are truly 'restoration-ready.' Plant materials that are not restoration-ready will fail to persist in the marketplace and ultimately provide little value.
Technical Abstract: While seed harvested from remnant stands of grass can be used for restoration in temperate regions, seed recovery in semi-arid and arid environments is often unreliable and of low yield and quality. In addition, ongoing harvest of indigenous populations can be unsustainable, especially for those that are small. Dependable and repeatable broad-scale restoration of degraded grasslands requires sufficient and consistent supplies of reliable, cost-effective seed sources that can only be consistently obtained from intensively managed cultivated stands. However, does the harvest of intensively managed seed-production fields inadvertently compromise genetic diversity, thereby adversely affecting the restoration outcome? That is, are seed-production systems a part of the solution for restoration, or do they create new unintended management issues? This paper discusses the likely impacts of cultivated seed-production systems and recurrent artificial selection for specific traits on genetic integrity and performance of native-species populations. Although genetic shift resulting from cultivated seed production may be inevitable, genetic shifts that change phenological expresion may be limited if seeds exhibit a non-shattering mechanism. Artificial selection can improve plant material performance under the often harsh conditions of sites targeted for restoration, but sufficiently high effective population sizes (Ne) must be maintained to conserve genetic diversity, thereby precluding inbreeding depression, which can compromise plant performance. Potentially useful traits that respond to artificial selection include seed production, shattering tolerance, seedling establishment, competetitive ability against weeds, and herbicide tolerance. Potential trade-offs between traits should also be given consideration to avoid undesirable inadvertent responses to selection.