ARS | Publication request: Fingerprinting the bad guys, SSR DNA-profiling of Nutsedge

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 25, 2009
Publication Date: N/A

Interpretive Summary: Determining genetic diversity among accessions of an invasive weed as purple nutsedge, its spatial spread, new introductions, possible hybridizations or herbicide resistance are key factors to implement effective management practices. We have developed the first molecular markers for this species which not only distinguish accessions from different countries but also can discriminate samples from continental USA. In addition we have observed a large level of genetic divergence and heterozygosity on three accessions originated from Arkansas and Mississippi, which could indicate higher environmental plasticity or potential adaptability of these populations.

Technical Abstract: Purple nutsedge (Cyperus rotundus L.), is considered among the world’s worst weeds and currently no information on the genetics of this species is available that could help determining diversity among accessions, spatial spread, new introductions, possible hybridizations or herbicide resistance. A total of 191 microsatellites were developed and tested on 13 accessions from 10 different countries. We identified 28 single-sequence repeat (SSR) markers that amplified all 13 accessions and were polymorphic. A large percentage of the markers (42%) amplified almost exclusively the sample from which the markers were isolated; this corroborates the clonality previously observed for this species. Heterozygous loci ranged from 24 to 60%. Genetic variation was observed among samples from around the world and also among samples from continental USA. We expect that these markers will become a useful tool in identifying biotypes or populations of purple nutsedge in order to implement management practices for the effective control of this weed.