Agriculture Reference
In-Depth Information
northern Europe for example,
Potato mop-top
virus
(PMTV) is an important cause, while in
temperate regions more generally,
Tobacco rattle
virus
(TRV) is often important. The disease syn-
drome that PMTV and TRV cause in tubers is
called “corky ringspot” in North America and
“spraing” in Europe (e.g. Harrison and Jones,
1971; Stevenson
et al
., 2001; Xu
et al
., 2004;
Santala
et al
., 2010). In the 1980s in Europe, a
tuber quality defect called potato tuber necrotic
ringspot disease (PTNRD) was recognized and
associated with PVY infection (e.g. Beczner
et al
.,
1984; Steinbach and Hamann, 1989). PTNRD
was subsequently found in North and South
America, Asia, Africa, and New Zealand (e.g.
McDonald and Singh, 1996; Oshima
et al
.,
2000; Boonham
et al
., 2002; Fletcher and Lister,
2004; Sawazaki
et al.
, 2009; Djilani-Khouadja
et al
., 2010; Gray
et al
., 2010; Kogovsek
et al
.,
2010). PVY has now become an important
cause of viral tuber necrosis disease in most
parts of the world. In Australia, potato tuber
necrosis caused by TSWV has always been im-
portant (e.g. Wilson, 2001), but PVY was trad-
itionally considered unimportant (e.g. Holmes
and Teakle, 1980; Wilson and Jones, 1990; Holland
and Jones, 2005). This situation may change
soon following the appearance of PTNRD caused
by PVY in the south-east of the continent in
2003 (Rodoni, 2005; Kehoe and Jones, 2011).
severe rugose virus
and
Tomato chlorosis virus
,
invaded potato plantings in southern Brazil (Souza-
Dias
et al
., 2008; Freitas
et al
., 2012). Three be-
gomoviruses,
Tobacco mottle Taino virus
(ToMoTV),
Tomato leaf curl New Delhi virus
(TLCNDV), and
Potato yellow mosaic virus
(PYMV), provide ex-
amples where the potato crop has been invaded
in subtropical zones outside South America. To-
MoTV and PYMV infect potato in the Caribbean
region, and TLCNDV in the Indian subcontinent
(Cordero
et al
., 2003; Urbino
et al
., 2004; Usharani
et al
., 2004; Valconen, 2007; Jones
et al
., 2009).
Like begomoviruses, tospoviruses also in-
vade new hosts readily. Initially, TSWV was the
only tospovirus known to infect potato, but over
the last two decades the number found infecting
the crop increased (
Table 12.1
). In the 1990s in
India,
Groundnut bud necrosis virus
(GBNV) was
recognized as the cause of a stem necrosis dis-
ease resulting in considerable losses in potato
crops (e.g. Pappu
et al
., 2009). Also in the 1990s,
Groundnut ringspot virus
and
Tomato chlorotic spot
virus
(TCSV) were found infecting potato in Ar-
gentina, and TCSV in Brazil (Nagata
et al
., 1995;
Granval de Mill ´n
et al
., 1998; Jeffries, 1998).
More recently,
Impatiens necrotic spot virus
(INSV)
and
Tomato yellow fruit ring virus
were both
found infecting potato in Iran (Golnaraghi
et al
.,
2008; Pourrahim
et al
., 2012), and INSV in
greenhouse-grown potato in North America
(Perry
et al
., 2005; Crosslin and Hamlin, 2010).
Begomoviruses and tospoviruses
Other viruses
Begomoviruses evolve rapidly (e.g. Navas-Castillo
et al
., 2011) and occur widely in subtropical re-
gions where potato is increasingly being grown
to help address food insecurity issues
(
Table
12.1
). There are increasing numbers of ex-
amples where begomoviruses invaded potato
after the crop was introduced to such regions.
Potato deforming mosaic virus
(PDMV) spread to
potato when it was grown in Argentina and
southern Brazil, where PDMV had been known
to occur for
60
years (Calderoni, 1965; Faria
et al
.,
1997). PDMV is now considered to be the same
begomovirus species as
Tomato yellow vein streak
virus
(Ribeiro
et al
., 2006). Thirty years ago,
So-
lanum apical leaf curl virus
invaded potato when
it was introduced to the subtropical high jungle
of Peru (Hooker and Salazar, 1983). Recently, two
new tomato-infecting begomoviruses,
Tomato
As the potato crop becomes more widely grown
in countries with warm climates, it will become
increasingly exposed to new encounters with
viruses spreading from native plants. Such new
encounters provide new opportunities for rapid,
adaptive virus evolution and host species jumps
(Woolhouse
et al
., 2005; Fargette
et al
., 2006;
Jones, 2009), so the number of viruses found in-
fecting the crop is likely to increase further. Also,
the increasing rapidity and volume of trade in
plant produce and movement of potato cultivars
around the world is likely to increase the distribu-
tion of potato viruses formerly of restricted distri-
bution. For example, several viruses that infect
cultivated and wild potato species in the Andean
region have not yet become established in other
