Abstract Detail

Population Genetics/Genomics

Wedger, Marshall [1], Olsen, Kenneth [2].

Genomic consequences of changing agricultural practices on weedy rice.

Changing agricultural practices have changed the selective pressures imposed upon agricultural weeds.  The introduction of herbicide resistant cultivars has, unsurprisingly, increased the strength of selection for herbicide resistance in the weeds.  At the same time, the introduction of hybrid cultivars has increased volunteer rates leading to elevated rates of hybridization between agricultural weeds and their cultivated relatives.  Weedy rice is a de-domesticated (feral) form of cultivated rice that infests rice fields world-wide.  If left unchecked, a weedy rice infestation of just eight plants per m2 can reduce yield by up to 80%.  In the present study we have collected 48 samples from Green County, Arkansas.  We have collected weedy rice samples from fields with three cropping histories, including Clearfield inbred (herbicide resistant), Clearfield hybrid, and non-Clearfield hybrid fields.  Whole genome sequences from these samples, combined with previously published whole genomes from weedy rice samples collected before these farming practices were implemented, should allow us to determine the genomic consequences of a changing agricultural landscape. Specifically, we ask 1) are levels of herbicide resistant weeds higher in those fields with a history of herbicide resistant crops? 2) given that these weeds were collected in fields that apply herbicides, are the mechanisms of resistance similar to the crop, suggesting that the weed gained resistance through rare outcrossing events? And 3) given that an herbicide resistant F1 hybrid is 50% crop and 50% weed, has natural selection preferentially selected one genome over the other?

1 - Washington University In St. Louis, Biology, 1 Brookings Drive, St. Louis, MO, 63130, United States
2 - Washington University, Biology Dept., Campus Box 1137, 1 Brookings Drive, St. Louis, MO, 63130, United States

Weedy Rice
Whole Genome Sequencing
Hybrid Rice.

Presentation Type: Poster This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPG008
Abstract ID:505
Candidate for Awards:None

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