Impatiens necrotic spot virus
Cymbidium ringspot virus
(INSV) is a Tospovirus related to
(CymRSV) is a Tombusvirus. SympTSWV, but is distinct enough such
toms that appear are generally a
that it is a separate virus. Symptoms
chlorotic ring mottle pattern on the
and methods of transmission are
leaves. CymRSV can occur as a dual
similar to TSWV.
or triple infection with CymMV
Capsicum chlorosis virus - Phaand/or ORSV causing an intensifilaenopsis isolate (CaCV) is also a
cation of symptoms.
Tospovirus like TSWV and INSV.
Tomato ringspot virus (ToRSV) is
CaCV was originally found in pepa Nepovirus often spread by nemaper, but was found to infect orchids,
todes, though usually not for ororiginally Phalaenopsis from Taichids. The culprit nematodes generwan, where it may or may not have
ally inhabit soil only and are unlikely
truly originated. It had once been
to inhabit epiphytic media used for
known as “Taiwan Phalaenopsis
most orchids. Nematode transmisvirus” until proven as an isolate of
sion is more of a risk for terrestrial
CaCV.
orchids grown in soil and mechaniCucumber mosaic virus (CMV) is a
cal transmission is the more likely
Bromovirus which can be spread by
threat to most orchids. Symptoms
aphids. Orchid symptoms include
occurring on foliage include chloyellow streaks occurring lengthwise
rotic spots or rings with possible
on the foliage with mild color break
leaf deformation.
on the flowers. Leaves may be disTobacco rattle virus (TRV) is a Totorted in a long “shoe-string” manbravirus also associated with nemaner.
tode transmission. As described
Bean yellow mosaic virus (BYMV) Figure 3 - ORSV infected Cattleya species. with ToRSV, nematodes should only
is a Potyvirus with a wide host range
be a threat to terrestrial orchids and
Photo: Dr. R. McMillan, Homestead Florida
and can be aphid transmitted. Mascontaminated tools are the primary
devallia and Calanthe are believed
threat of TRV amongst orchid hobbyists. Symptoms generally
highly susceptible to some strains. Symptoms include patterns occur on foliage as yellow line patterns, ringspots, necrotic
of chlorotic spots or flecks on the foliage. Flower symptoms specks, or misshaped perhaps dry leaves.
may include color break or distortion. Other Potyvirus-group
There are many more viruses that have been found to make
viruses related to BYMV known to infect orchids include:
orchids their host, and probably many more to be discovered
Clover yellow vein virus (ClYVV); Dendrobium mosaic vi- in the future.
rus (DeMV); Phalaenopsis chlorotic spot virus (PhCSV); and
Turnip mosaic virus (TuMV)
Don’t make assumptions. You have testing options:
Vanilla mosaic virus (VanMV) is a similar Potyvirus. This ...Laboratory Based Testing: There are about thirty docuvirus was originally found in Vanilla orchids cultivated for mented orchid viruses, seventeen are confirmed. With the exvanilla beans which remain the only known hosts. However, ception of Orchid fleck virus (OFV), assays for the detection of
with the increasing interest amongst hobbyists to grow Va- the viruses we have talked about are readily found in the US.
nilla orchids, so increases the possibility of VanMV finding Some are laboratory based assays offered by agricultural diagits way into a collection. Symptoms on foliage often include a nostic facilities such as university diagnostic clinics or private
chlorotic or necrotic mosaic pattern.
companies such as Agdia, Inc/Agdia Testing Services. This
Carnation mottle virus (CarMV) is a Carmovirus spread by option is a way to screen your orchids for a large number of
mechanical transmission and notorious for remaining infec- viral pathogens. Samples submitted to Agdia Testing Services,
tious on tools or workbenches for long periods of time. Symp- requesting the Orchid Screen, would be tested for:
toms appear on foliage as chlorotic spots, often in a pattern
Cucumber mosaic virus - CMV
across the leaves.
Cymbidium mosaic virus - CymMV
8
Phalaenopsis | Fourth Quarter | Volume 23 | 2013