Submitted to: Plant Animal and Microbe Genomes Conference
Publication Type: Abstract only
Publication Acceptance Date: 10/24/2012
Publication Date: 1/12/2013
Citation: Johnson, R.C. 2013. Genecology of Indian ricegrass in the Southwest. Plant Animal and Microbe Genomes Conference. https://pag.confex.com/pag/xxi/webprogram/Paper4897.html. Interpretive Summary:
Technical Abstract: The USDA National Plant Germplasm System (NPGS) maintains extensive collections of cool-season perennial grasses available though the Plant Germplasm and Testing Unit at Pullman, WA. Among these are rangeland grasses, essential for ecosystem function, but threatened by invasive weeds and frequent fires. Research linking quantitative genetic variation in rangeland grasses with climate across the landscape is generally lacking and needed to provide guidance for choosing the most suitable germplasm for restoration. The NPGS collection of Indian ricegrass [Achnatherum hymenoides (Roemer & J.A. Schultes) Barkworth], representing 106 collection locations from the southwestern US were evaluated in common gardens. Four phenological traits (Phen) (such as blooming date), six production traits (Pro) (such as dry weight), and 8 morphology traits (Morph) (such as leaf dimensions) were measured in 2007 and 2008. Analyses of variance revealed that all basic garden traits differed among source locations (P<0.01), indicating widespread genetic variation. Within Phen, Pro, and Morph categories, canonical correlation between basic garden traits and source location temperature and precipitation resulted in six significant (P<0.01) variates. Using regression modeling between significant variates and climate, a map with 12 seed zones was developed encompassing more than a million square-km in the southwestern US. The correspondence between climate and quantitative variation suggested climate driven differences in natural selection, likely leading to adaptation. This seed zone approach is being pursued in other key grasses to guide rangeland restoration and broaden germplasm collection and utilization.