Location: Forage and Range Research2012 Annual Report
1a. Objectives (from AD-416):
The objectives of this cooperative research agreement are: 1) Analyze the plant nutritional components of fescue grasses with and without fungal endophytes which have been subjected to drought, heat, and salt stress; 2) Analyze the water soluble carbohydrates of orchardgrass and ryegrass experimental lines which have been subjected to drought and temperature stress; and 3) Determine the concentration of selenium (Se) and other toxic heavy metals of native plant species after being grown in soils from various degraded mining sites. Results will allow for the identification of novel stress tolerant plant materials that will thereafter be selected for pre-requisite traits (persistence, productivity) for public release.
1b. Approach (from AD-416):
This project will focus on response of native and non-native (introduced) plant species when challenged by several abiotic stresses (drought, salt, temperature, and heavy metals). This research will have field, laboratory, and greenhouse components and will involve the mineral analysis of plant species to define their responses to abiotic stress challenge. The response of plant populations and experimental lines (the result of previous breeding from ongoing plant improvement programs) that have been identified in preliminary experiments to possess tolerance and susceptibility to abiotic stresses will be subjected to stresses in replicated trials and will be prepared for analysis by mass spectrometry. For fine-leaf fescue analysis, clonal plants which are + and - endophytes will be evaluated for their response under controlled field (rainout shelter) and greenhouse (overhead delivery system) for water and salt stress challenge, respectively. For orchardgrass and ryegrass experimentals challenged with water (line source) and temperature (cold) stress, whole and biochemical analysis coupled with near-infrared spectroscopy of leaves will be accomplished by wet chemistry to determine water soluble carbohydrate concentration. For plants subjected to heavy metal challenge either in the field or greenhouse, mass spectrometry will be employed to determine the effect of animal manure, sulfur, and denwoody cap treatments on different forms of heavy metals (e.g., Se in Se overburdened soils).
3. Progress Report:
During FY-2011: Perennial grasses are regularly used to rehabilitate soils contaminated with heavy metals and other phytoxic minerals such as selenium (Se). This report serves to document the work to date on the third objective, which is to determine the concentration of selenium (Se) and other toxic heavy metals of native plant species after being grown in soils from various degraded mining sites. Study 1: A quantitative trait loci (QTL) study was conducted using containers filled with phytoxic soil from the Clark Fork River floodplain of western MT (largest U.S. Superfund Site). Clark Fork soil has toxic levels of Cd, Cu, Mn, Pb, Zn, and As conducted on a soil from the North Fork of the Anaconda Superfund clean-up to identify genetic markers controlling the uptake and exclusion of heavy metals. The greenhouse portion of the study is complete. The samples will be ground and run through the ICP-OES (optical emission spectrum) for Cd, Cu, Mn, Pb, Zn, and As uptake concentrations. QTL markers associated with the uptake and accumulation of heavy metals will be used in MAS to develop forage grasses that increase grazing safety on contaminated soils Study 2: A germination study was completed comparing germination rates of ‘Luna’ intermediate wheatgrass (WG), ‘Vavilov II’ Siberian WG, ‘Recovery’ western WG, ‘FirstStrike’ slender WG, ‘Bozoisky II’ Russian wildrye, ‘Bromar’ mountain brome, ‘Cache’ meadow brome, ‘Sherman’ big bluegrass, Prairie junegrass, ‘Nortran’ tufted hairgrass at a control, cap material, 16_ppm Se, 35_ppm Se, and 70_ppm. Germination rates across all grasses ranged from 13.9 in Luna intermediate WG to 6.2 seedling germination per day in tufted hairgrass. There was a significant decline in germination rate at 70_ppm while germinate rates in the other Se levels were not significantly different. Study 3: A greenhouse tube study is currently under comparing the grass species in Study 2 ability to uptake Se. Treatments include a control, 6 inch cap material with 35_ppm Se soil below, 12 inch cap, 18 in cap, and straight 35_ppm soil. Forage harvests at 35 and 70 days have been completed. The study will continue for 180 days and then ground forage samples will be analyzed using the ICP-OES (optical emission spectrum) for Se.