Abstract Detail

Population Genetics/Genomics

Tamrakar, Rubin [1], Bailey, C. Donovan [2], Lehnhoff, Erik [1], Sahd, Kyle [3].

An Assessment of Genetic Variation Associated with Differential Response to Fire Among Populations of Cheatgrass (Poaceae, Bromus tectorum).

The invasive grass Bromus tectorum (cheatgrass; downy brome) has been a longstanding problem in the western grasslands of the United States. Native to North Africa and Eurasia, the historical records suggest cheatgrass seeds were introduced into the US via imported grains and seed for novel grazing grass experiments in the mid-1800s. It has subsequently spread as a result of seed dispersal by livestock, agriculture and other anthropogenic activities.  The Great Basin and Colorado Plateau are some of the regions experiencing the greatest impacts because of ideal habitat suitability, particularly temperature and precipitation patterns. Using 25 allozyme markers on population samples, Pawlak et al. (2014) previously found that the US populations display lower inter- but higher intra-population variation when compared to populations from the native range. The combination of those findings suggest that a mixture of several founder populations contributed to invasive genotypes in the US. Thus, genetic variation clearly exists across the landscape, but few studies have looked to see how that variation may partition within and between populations from the same general region. In northern New Mexico, BLM land managers have observed populations of cheatgrass that appear to vary in their response to fire, suggesting potential genetic differentiation between populations. Here we investigate whether the observed differential response to fire is associated with underlying genetic variation. The project involves the use of a population genomic markers (Angiosperm 353) derived from 25 individuals for each of six populations from northern NM.  The sampling also includes 17 herbarium samples from across the state to represent historical patterns of introduction to the state. Findings from this study will ideally guide land management decisions related to prescribed fire regimes and cheatgrass management, while also providing a basic understanding of genetic variation within and between a number of geographically proximate populations of cheatgrass.  

1 - New Mexico State University, 1780 E University Ave, Las Cruces, NM, 88003, United States
2 - New Mexico State University, Biology, Rm 120 Foster Hall (Stores), Dept Of Biology - New Mexico State University, Las Cruces, NM, 88003, United States
3 - Bureau of Land Management, 6251 College Blvd., Suite A, Farmington, NM, 87402, USA

genetic variation

Presentation Type: Poster
Session: P, Population Genetics/Genomics Posters
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 5:00 PM Time and date to be determined
Number: PPG008
Abstract ID:674
Candidate for Awards:None

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