An international team of researchers has sequenced the genomes of the Mexican avocado, Persea americana var. drymifolia and the common commercial hybrid cultivar, Hass. As the researchers report this week in the Proceedings of the National Academy of Sciences, they also resequenced Guatemalan and West Indian avocado varieties to find that the Hass cultivar is the result of a Guatemalan variety introgressed onto a Mexican avocado background.
The researchers also traced back the phylogenetic history of the avocado to try to determine the relationship between avocados and flowering plants, finding that the magnoliids — the group of plants to which avocados belong — may predate the eudicot and monocot lineages. "Because magnoliids diverged from other major flowering plant groups so rapidly and so early on, at a time when other major groups were also diverging, the whole thing is totally damn mysterious," author Victor Albert from the University at Buffalo says in a statement. "We made contributions toward finding an answer by comparing the avocado genome to the genomes of other plant species, but we did not arrive at a firm conclusion."