Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/14/2003
Publication Date: 11/2/2003
Citation: Jessup, R.W., Burson, B.L., Renganayki, K., Hussey, M.A. 2003. Fine mapping of papol: The apomixis locus in buffelgrass [abstract]. Agronomy Abstracts. Paper No. CO7-Jessup246797.
Technical Abstract: Apomixis (asexual reproduction through seed) is a trait of agronomic importance that has received much attention with the advent of modern molecular technologies. Mapping studies have revealed that a single genetic locus exerts major control over apomixis in several grass species. However, detailed mapping efforts have been complicated by suppressed recombination in this region. Several approaches have been taken to dissect the apomixis locus, PApo1, in buffelgrass (Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.). First, bulked-segregant-analysis (BSA) was used to saturate the region where PApo1 is located. In addition to 2 previously identified RFLPs, 1 SSR and 10 AFLPs were closely linked to PApo1. Second, the buffelgrass mapping population was increased from 87 to 200 hybrids in order to identify additional recombinant genotypes. Only one more recombinant genotype was identified in the additional hybrids, which kept the map resolution relatively constant near PApo1. Third, association mapping of markers linked to PApo1 was conducted across 250 buffelgrass plant introductions. This approach identified additional recombination events flanking the PApo1 locus that have occurred during the evolution of buffelgrass, and these have increased the map resolution around the locus. Implications this research has towards map-based cloning of the apomixis gene(s) will be discussed.