|Skinner, Daniel - Dan|
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2003
Publication Date: 7/15/2003
Citation: Steinau, A.N., Skinner, D.Z., Steinau, M. 2003. Mechanism of extreme genetic recombinaton in weedy amaranthus hybrids. Weed Science. 51(5):696-701. Interpretive Summary: Two different kinds of pigweeds are known to cross-pollinate and form hybrids. Some of the genetic material (DNA) in the hybrids are different from both parents. In this research, we found that some of these differences are because of pieces of DNA that are capable of physically moving to new locations in the genome. This finding indicates that the hybrid plants may provide variation to the pigweed population that is not present in either parent population, possibly providing new strains of pigweeds that can become problem infestations.
Technical Abstract: The genus Amaranthus includes approximately 60 species distributed throughout the world, including cultivated grain crops as well as weed species. Ten species are considered significant weeds. It previously was shown that interspecific hybridization of A. palmeri (Palmer amaranth) and A. rudis (Common waterhemp) produce hybrids with unique DNA fragments not found in either parent. The objective of this research was to investigate the mechanisms involved in the formation of these polymorphic fragments. Southern blot analysis using one of the novel fragments as probe revealed a consistent pattern of repetitive DNA that was species and biotype specific. Six novel fragments were cloned and sequenced. Five of the six were significantly similar to plant transposons, the sixth was similar to squamosa promoter binding proteins from other plant species. These results indicate that transposon-like elements may play an important role in the formation of new fragments in Amaranthus hybrids derived from interspecific hybridization.