The Westward Journey of Alfalfa Leaf Curl Virus.

Alfalfa leaf curl virus (ALCV), which causes severe disease symptoms in alfalfa ( L.) and is transmitted by the widespread aphid species, Koch, has been found throughout the Mediterranean basin as well as in Iran and Argentina. Here we reconstruct the evolutionary history of ALCV and attempt to determine whether the recent discovery and widespread detection of ALCV is attributable either to past diagnostic biases or to the emergence and global spread of the virus over the past few years.