Progress On Genetic Linkage Mapping in Diploid Buffalograss (Buchloe dactyloides (Nutt.) Engelm.).

Buffalograss genetic linkage mapping was initiated to construct a framework linkage map on progeny from a cross between a male and female diploid genotypes differing in gender expression, turf quality and internode length. The parents were crossed in the greenhouse, and were isolated from any other source of buffalograss pollen. The parents were polymorphic for SRAP and SSR markers, and 94 F1 progeny from the mapping population were genotyped for the same polymorphic markers.  These data were subjected to linkage mapping analysis using ‘OneMap’ (i.e. a package in R statistical Analysis Software), which was developed for outcrossing plant species.  Out of 54 informative SRAP and SSR markers, 43 markers aligned into nine linkage groups against the haploid chromosome number of diploid buffalograss (N=10).  The number of markers per linkage group ranged from 2 to 18, with 5 as the average.  The distance between the loci estimated from the recombination frequencies ranged from 0.009 cM to 33 cM.  Linkage group number 2 had the largest number with 18 loci linked.  It probably contains many genes that control various traits or may be the largest chromosome in the buffalograss genome.  This study has laid a foundation for defining the linkage groups of the diploid buffalograss genome that will serve as an avenue for future genetic analysis of important traits.