1) Genetic Architecture of Apomixis — My previous work has shown that apomixis in Erigeron is regulated by two separate loci. Additional experiments have explored the inheritance of these loci and demonstrated that apomictic development can be recreated by experimentally recombining the two separate gene regions. My pending proposal to the National Science Foundation (January 2006 – Biology: Genes and Genome Systems Cluster) is to develop two mapping populations (one based on maternal segregation and the other based on paternal segregation) as robust sources of markers linked to apomictic reproduction. These markers will provide a means to explore the genetic and physical structure of apomictic genome regions. My ultimate questions relate to the origin and evolutionary history of these regions.

Fig. 1. Genetic model. Apomixis in Erigeron annuus is controlled by two separate loci: ‘D’ causes diplospory (unreduced gametophyte formation); ‘F’ induces autonomous embryo and endosperm formation. These two factors segregate independently in crosses to yield four phenotype classes.

Fig. 3. Genetic map for apomixis in Erigeron annuus featuring separate linkage groups for ‘D’ and ‘F’. Map distances between AFLP markers given in centimorgans.