RESEARCH, ACQUISITION, MANAGEMENT, AND DOCUMENTATION OF PLANT GENETIC RESOURCES
Location: Plant Germplasm Introduction and Testing
Title: Genecology and seed zones for Indian Ricegrass across the southwest USA
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 2011
Publication Date: January 28, 2012
Citation: Johnson, R.C., Cashman, M.J., Vance-Borland, K. 2012. Genecology and seed zones for Indian Ricegrass across the southwest USA. Meeting Abstract. http://www.rangelands.org/spokane2012.
Restoration of rangelands is increasingly critical as biotic and abiotic stress compromise habitat quality. In the Western US, Indian ricegrass [Achnatherum hymenoides (Roemer & J.A. Schultes) Barkworth] is a native, widely distributed, highly desirable species in desert ecosystems. Yet there are no studies that match genetic variation in Indian ricegrass with climate across large areas of its natural distribution. Seeds from 106 locations across the Southwestern US were established in common gardens and phenological traits, production traits, and morphology traits were measured in 2007 and 2008. Analyses of variance revealed that all traits differed among collection locations, indicating genetic variation (P<0.01). Canonical correlation of garden traits and climate (annual and monthly temperature and precipitation) within phenology, production, and morphology categories resulted in one significant variate for phenology, two for production, and three for morphology (P<0.01). Linear correlations between monthly temperature and the first canonical variate for phenology, averaging r= 0.46, and production averaging r= -0.46 were all significant (P<0.01). However, correlation patterns for monthly precipitation for the same variates showed a strong seasonal pattern; highest during April, May, and June, averaging r= -0.43 and 0.48, respectively, and relatively weak in the summer and fall months. Regression models of three canonical variates with climate (R2 = 0.72, 0.59, and 0.49) resulted in 12 mapped seed zones representing much of the Southwestern US. We recommend utilization of the seed zone map to guide and broaden germplasm selection for future restoration needs.