Disease Note. First Report of Tomato Spotted Wilt Virus in Manitoba and of Lathyrus sativus as a Host. R. C. Zimmer, Agriculture Canada Research Station, Morden, MB R0G 1J0. S. Haber, Agriculture Canada Research Station, Winnipeg, MB R3T 2M9. Plant Dis. 76:753. Accepted for publication 3 March 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0753A. In 1990 and 1991, severe outbreaks of a disease caused by Tomato
spotted wilt virus occurred in grass pea (Lathyrus sativus L.) and
field pea (Pisum sativum L.) (1) in greenhouses at the Agriculture
Canada Research Station, Morden, Manitoba, Canada. The virus can
be transmitted by the western flower thrip (Frankliniella occidentalis
(Pergande)), which was abundant. Infection with the impatiens strain
of Tomato spotted wilt virus (TSWV-I) was confirmed by enzyme-linked
immunosorbent assay. In 1991, TSWV-I also was confirmed
by ELISA in ornamental impatiens at the conservatory greenhouse,
Assiniboine Park, Winnipeg, and in potato, tomato, petunia, and
Nicotiana sp. in the research station greenhouses at Morden. On L.
sativus, the most conspicuous symptom was purplish discoloration
of the pod. Straw-colored areas appeared on stems, extending from
the node up and down the stem. Severe infection resulted in complete
ovule abortion, especially at the top node. Symptoms on field pea,
in addition to ovule abortion, included tan or light green wilted areas
with a purplish tinge on leaves, purplish brown streaks of variable
lengths on stems, and irregular purplish areas or purple ring spots
on pods. |