Submitted to: International Symposium on Molecular Breeding of Forage Crops Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2000
Publication Date: N/A
Technical Abstract: The first genetic map of buffelgrass (Pennisetum ciliare (L.) Link Syn. Cenchrus ciliaris L.), an important apomictic forage species, is reported. Female- and male-derived maps were constructed using RFLPs in a population of 87 F1 hybrids segregating for method of reproduction (apomictic vs. sexual). A survey of 862 cDNAs and gDNAs from across the Poaceae, as well as 443 buffelgrass cDNAs, yielded 100 and 360 polymorphic probes, respectively. The female parent's map included 409 RFLPs, 47 linkage groups, and was 3464 cM in length, while the male parent's map contained 300 RFLPs, 42 linkage groups, and was 2757 cM. Approximately 70-80% of the buffelgrass genome was covered, with average marker spacings of 10.8 and 11.1 cM on the respective maps. While the finding of repulsion within many linkage groups supports cytological reports that the species is a segmental allotetraploid, greater preferential pairing in the female parent than the male parent was indicated across linkage groups (55% vs. 38%) and loci (48 vs. 15%). Comparison of interval lengths in 15 allelic bridges suggested significantly less meiotic recombination in gametes of the male parent. Current efforts include saturating the map with additional markers, joining the maps, and placing traits of interest onto the map.