EPPO Global Database

EPPO Reporting Service no. 05 - 1993 Num. article: 1993/95

Tomato big bud MLO transmitted by Circulifer tenellus

It is still not absolutely resolved if tomato big bud MLO is just a synonym of potato stolbur MLO (EPPO A2 quarantine organism) or a distinct disease. Experiments in California, US, were carried out to investigate the causal agent of the disease and its vector.

It was established, by using biological and genetic data, that the causal agent of tomato big bud disease is the beet leafhopper-transmitted virescence agent MLO. The leafhopper Circulifer tenellus was able to acquire the MLO from field-collected symptomatic tomato plants and transmit it to healthy tomato plants which consequently developed typical big bud symptoms. The aster leafhopper Mocrosteles fascifrons failed to transmit the MLO to healthy tomato plants and tomatoes inoculated with western aster yellows MLO did not develop floral gigantism or virescence.


Shaw, M.E.; Kirkpatrick, B.C.; Golino, D.A. (1993) The beet leafhopper-transmitted virescence agent causes tomato big bud disease in California.
Plant Disease 77; 290-295.