Plant & Animal Genomes XV Conference Plant & Animal Genomes XV ConferenceJanuary 13-17, 2007
Town & Country Convention Center
San Diego, CA
Michael Bevan1 , Neil McKenzie1 , Martin Trick1 , John Snape1 , Todd Mockler2 , John Vogel3 , David Garvin4
Establishing a genetic map of Brachypodium distachyon Bd21 is an important initial project of the International Brachypodium Initiative. Genetic maps will provide anchor points linking the genome of Brachypodium with those of rice, wheat and bioenergy crops, and they will establish chromosome- scale orders of whole genome shotgun sequences and physical maps of BACs. The mapping populations currently comprise several hundred F2 lines derived from a cross of Bd21 and Bd3-1 inbred lines. These will be taken to F6 to establish NILs that can be used as a common mapping resource by the community. Several approaches have been taken to identify polymorphisms. First, conserved orthologous (COS) markers derived from wheat and millet were used to identify a set of 80 confirmed polymorphisms between these two lines. Another strategy used the sequences of Bd21 ESTs (generated by John Vogel and his colleagues) to identify more polymorphisms. The most productive approach has been to predict introns in Brachypodium based on comparison of Bd21 EST sequence to the annotated rice genome sequence. Nearly 500 introns were predicted, and nearly all of these generate PCR products. So far over 80% all the PCR products are polymorphic among the 5 inbred diploid lines screened on denaturing gels, and about 20-25% are polymorphic between Bd21 and Bd3-1. Currently we are working through these predictions, which may yield up to a 100 useful markers. Thus we anticipate having generated approximately 200 markers for mapping. Currently we are screening about 200 F2 lines from a Bd21- Bd3-1 cross and results will be presented at the Workshop.