Plant & Animal Genome IX Conference

Workshop: Forage & Turfgrass
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ALIGNMENT OF PENNISETUM CILIARE AND SORGHUM BICOLOR CHROMOSOMES BASED ON EST-ENRICHED GENETIC MAPS

¹ Center for Applied Genetic Technologies, Univ. of Georgia, Athens, GA 30602

² Dept. of Soil and Crop Sciences, Texas A & M Univ., College Station, TX 77843

³ USDA-ARS, College Station, TX 77843

The genetic map of buffelgrass (Pennisetum ciliare (L.) Link), a tetraploid forage grass has been developed using cDNA from an apomictic pistil library of the species and genomic clones from a number of other grass species. Detailed alignment of the buffelgrass map to the high density map of sorghum (containing approx. 2600 loci), has been established to facilitate molecular analysis of its complex genome. A total of 150 markers common to buffelgrass and sorghum have been mapped to both species covering all sorghum linkage groups (LGs). Based on parallel arrangement of these duplicated loci and using sorghum LGs as anchor, homologous groupings of buffelgrass LGs has been assembled. Notably, the apomixis gene region PApo1 identified in LG8b from buffelgrass PI 409164 (apomictic male parent) clearly corresponds to a region in sorghum LG-D. The two closest flanking markers to PApo1 in buffelgrass co-segregate in sorghum. Physical mapping in sorghum is in progress to identify a contig of BACs that encompasses this region and to identify candidate orthologs for apomixis genes. Utilization of the high density map of sorghum as a tool towards isolation of alleles conferring phenotypes unique to other closely related grass species will be discussed.