Location: Great Basin Rangelands Research
Project Number: 2060-22000-025-005-I
Project Type: Interagency Reimbursable Agreement
Start Date: Oct 1, 2016
End Date: Sep 30, 2021
Objective:
ARS-Reno and key collaborators will conduct laboratory, greenhouse and field
research on the biology, ecology, and genetics of medusahead (Taeniatherum
caput-medusae), cheatgrass (Bromus tectorum) and red brome (B. rubens), three
annual grass species of Eurasian origin that are invasive in the Great Basin and
Intermountain West, with the ultimate goal of discovering and developing effective biological control agents and other novel control strategies for these invasive grasses.
Approach:
ARS researchers and their collaborators will collect eriophyid mite species
and other natural enemies from medusahead, cheatgrass, and red brome
plants through native range surveys, followed by taxonomic, genetic and
biological (e.g. host-range) study of these natural enemies to assess their
suitability as classical biological control agents. Lineages of model eriophyid
mite species will be characterized using fine-scale DNA fingerprinting and
this data will be correlated with host-range traits and enable rapid screening
of field-collected mites. PCR-based genetic markers for the three targeted
grass species will be produced and utilized to describe relationships between
native and invasive populations, to understand weed invasion dynamics and
to identify putative native-range source regions for invasive weed
populations; all markers produced will be made available to the public. The
endophytic mycoflora of medusahead will be compared between its native
and invaded ranges to investigate possible roles of endophytes in the invasion
ecology of this grass. Selected target grass species populations will be
observed throughout their annual life cycles to identify and compare
important mortality trends between the native and invaded ranges.
