Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 8/12/2004
Publication Date: 10/5/2004
Citation: Jessup, R.W., Burson, B.L., Paterson, A.H., Hussey, M.A. 2004. Association mapping of Papo 1: The apomixis locus in buffelgrass [abstract]. American Society of Agronomy. 2004 CDROM. Interpretive Summary:
Technical Abstract: Apomixis (asexual reproduction through seed) is an important reproductive trait that has received much attention with the advancement of molecular tools. Linkage mapping studies have revealed that a single genetic locus exerts major control over apomixis in several grass species. However, suppressed genetic recombination in this region has prevented the production of high-resolution linkage maps required for map-based cloning. Association mapping has the potential to complement linkage studies by identifying polymorphisms within a candidate region. In this study, association testing was performed across 250 buffelgrass (Pennisetum ciliare [L.} Link syn. Cenchrus ciliaris L.) plant introductions for which flow cytometry had confirmed an euploid (2n=4x=36) chromosome number. Twenty markers distributed throughout the buffelgrass genome were used to identify distinct subpopulations, which were analyzed independently. Twelve markers within 4.6 cM of Papo1, the apomixis locus in buffelgrass, were evaluated for linkage disequilibrium within each subpopulation. This approach increased map resolution near the Papo1 locus and revealed the extent of linkage disequilibrium in this genomic region. Implications of this research towards map-based cloning of apomixis gene(s) will be discussed.