Molecular and Biochemical Tools for Characterization and Cultivar Improvement of Anthurium andraeanum Hort

The most striking and commercially attractive feature of the popular cut flower and potted plant Anthurium andraeanum Hort. is its spathe, a modified leaf typical of members of the family Araceae. Spathes are produced  in hues of pink, red, orange, coral, white and green.  However, the genetics governing spathe color, which is comprised of varying levels of the anthocyanidin pigments pelargonidin and cyanidin, are still not completely understood, making germplasm selection for breeding and prediction of spathe color in progeny for new cultivar development difficult.  Recently, we have embarked on a project to develop methods to measure biochemical variation responsible for the various spathe colors as well as to identify the associated genetic determinants to create diagnostic tools that would support cultivar improvement by molecular breeding and biotechnological approaches.  Towards this goal we are developing high throughput protocols to obtain pigment profiles from spathes using LC/MS, enabling detailed characterization of underlying biochemical phenotypes across sample populations.  In a second approach we have been examining potential sources of genetic determinants for observed spathe color variation by sequencing a gene encoding dihydroflavonol reductase (DFR) a key enzyme in the anthocyanin biosynthesis pathway. DFR is found in multiple copies throughout the eudicot and monocot genomes and it is known that sequence variation within a conserved region of the gene confers substrate-specificity.  To date we have identified distinct DFR genomic DNA sequences and present data of their distribution within and among Anthurium cultivars with very different pigment profiles as a model for identifying molecular markers for spathe color.  Finally, we have examined species in the genus Anthurium for their genome capacity in the context of phylogenetic relationships to better understand the evolutionary origins of genetic, floral and horticultural variation.