Solanaceae

Wang Y, Diehl A, Wu F, Vrebalov J, Giovannoni J, Siepel A & Tanksley SD 2008 Sequencing and comparative analysis of a conserved syntenic segment in the Solanaceae. Genetics 180:391-408.

• despite their great phenotypic diversity, all Solanaceae derived ~40 million years ago (MYA) from an ancestral diploid with x = 12 chromosomes
• nearly all family members have maintained this chromosome number
• members of the related family Rubiaceae (coffee family) are also diploid with x = 11 or x = 12
• any WGD in the history of the Solanaceae ad the Rubiaceae occurred before their divergence ~85 MYA

• the increased conservation of gene content observed in the Solanaceae is at least in part due to the absence of a recent WGD, as would be predicted by theory