2012 Annual Report
1a.Objectives (from AD-416):
1. Collect germplasm from diverse sites and ecological areas across the Great Basin.
2. Establish common gardens studies at contrasting sites, determine adaptive plant traits, and assess genetic variation across the landscape.
3. Using regression modeling, relate plant traits to environmental factors and develop seed transfer zones.
4. Conserve and distribute collected germplasm available through the Western Regional Plant Introduction Station seed repository and the National Plant Germplasm System.
1b.Approach (from AD-416):
Seeds collected from diverse areas in the Great Basin will be used in common garden studies at Central Ferry, WA, and either at Reno or Fallon NV, cooperative with University of Nevada and the Fallon Plant Material Center. Each garden will consist of seeds collected from at least 100 diverse locations. For each location there will be two families represented in a randomized block design with 6 replications. This will result in 1200 to 1800 plants per site per species. Numerous traits describing plant growth and devleopment will be measured on each plant. Analyses of variance will be conducted for each trait to determine seed source variation. Previous work with Mountain Brome, Tapertip onion, Bluegbunch wheatgrass and Indian ricegrass all show strong genetic variation across the landscape. So this result is expected for most species and suggests differences in adaptation to local environments. Principal components will be used with regression analysis to model the relationship between plant traits and local environmental factors such as precipitation, temperature and elevation. This will provide the basis for mapping seed adaptation zones.
Indian Ricegrass (Achnatherum hymenoides) is a key native grass on arid Western rangelands for grazing, soil stabilization, and wildlife habitat. In common garden studies, genetic variation in morphological, phenological, and production traits in Indian ricegrass was linked with climatic variation resulting in 12 seed zones representing a total of 1,084,476 square kilometers across the Southwestern US. Genetic variation was generally distinguished between cooler and warmer regions, usually separating more northern, higher elevation areas from more southern, lower elevation areas. Currently available genetic resources for restoration were found inadequate to represent the genetic diversity and climates across the Southwest. The correspondence between climate and genetic variation suggested climate driven differences in natural selection, likely leading to adaptation. The seed zone map is recommended to guide and broaden germplasm collection and utilization for Indian ricegrass restoration. Another species under study is Basin wildrye (Leymus cinereus), which provides both forage and cover to livestock and wildlife throughout the Intermountain West. A comprehensive collection of 125 basin wildrye accessions has been evaluated in replicated common gardens at Pullman and Central Ferry, WA. Data on morphological, phenological, and production traits was collected in 2011 and 2012. Genetic variation was extensive both between and within octoploid and tetraploid accession types. Evaluation will continue in 2013 and then genecology (study of species and their genetic subdivision, their place in nature, and the genetic and ecological factor controlling speciation) studies and seed zone development completed for Basin wildrye. Common gardens of Thurbers' needlegrass (Achnatherum thurberianum) and Bottlebrush squirreltail (Elymus elymoides), both important for grazing and wildlife in Western rangelands, were established in 2012 at Central Ferry, WA, and Reno, NV. First year data collection was completed for both species with an additional evaluation planned for 2013. The data will be used for genetic characterization and seed zone development. This progress is related to Objective 3 of the parent project: Strategically characterize (“genotype”) and evaluate (“phenotype”) crop core subsets and other priority germplasm for molecular markers, morphological descriptors, and key agronomic or horticultural traits, such as general adaptation, phenology, and growth potential.