Researchers have sequenced the genome of the microorganism that devastated the Irish potato crop in the 1840s — the first time the genome of a historical plant pathogen has been decoded.

Kentaro Yoshida at the Sainsbury Laboratory in Norwich, UK, and his colleagues identified the strain of Phytophthora infestans, which causes potato late blight, from nineteenth-century dried leaves. The researchers sequenced DNA from 11 historical specimens, which had been stored in herbaria, and from 15 modern strains of P. infestans. The famine strain was closely related to another strain that is still prevalent around the world, and the researchers suggest that the two strains diverged in the early 1800s. The famine strain may now be extinct, the authors say.

eLIFE http://dx.doi.org/10.7554/elife.00731 (2013)