Just spotted this in the news:
http://science.sciencemag.org/content/355/6323/391
A chemical genetic roadmap to improved tomato flavor
"Commercially available tomatoes are renowned these days for sturdiness, but perhaps not for flavor. Heirloom varieties, on the other hand, maintain the richer flavors and sweeter tomatoes of years past. Tieman
et al. combined tasting panels with chemical and genomic analyses of nearly 400 varieties of tomatoes. They identified some of the flavorful components that have been lost over time. Identification of the genes that have also gone missing provides a path forward for reinstating flavor to commercially grown tomatoes."
Unfortunately, could not get free access to the paper.
Hope a copy will turn up elsewhere.