Potato Tuber Necrotic Ringspot Disease Occurring in Japan: Its Association with Potato virus Y Necrotic Strain

Abstract

Unfamiliar necrotic symptoms on or within potato tubers of cultivars Nishiyutaka and Dejima were observed in Nagasaki prefecture, Japan, in 1992. Symptoms were typically on the surface of the tuber, which either protruded at first and then became sunken, or showed necrotic spots, with necrosis within the tubers. Symptoms sometimes appeared at harvesting but more often appeared after storage for several months. Investigations revealed that the causal agents of the disease were isolates of Potato virus Y necrotic strain (PVYNTN) and the disease was potato tuber necrotic ringspot disease (PTNRD), previously reported in Europe and Lebanon. Five potato cultivars were inoculated with an isolate from necrotic tubers. The highest percentage of progeny tubers showing PTNRD was found in cv. Nishiyutaka (23.3%). In contrast, cvs. Shima-bara, Mayqueen, and Danshaku showed a low percentage of PTNRD. Additional potato tubers with PTNRD were also observed after storage of the tubers. To investigate the relatedness between isolates of PVYNTN and of necrotic strain PVYN, previously isolated in Japan, Nishiyu-taka was inoculated with an isolate of PVYN, which also induced PTNRD. Nucleotide sequences of coat protein (CP) genes of six PVYNTN isolates were determined. The CPs were 267 amino acids in length, with a substitution of one or no amino acid among each of the six isolates. The phylogenetic relationship based on nucleotide sequences of CP genes showed that these six PVYNTN isolates clustered together with PVYN isolates. This is the first report of PTNRD caused by PVYNTN isolates in Asia.

Incidence of potato viruses and characterisation of Potato virus Y variability in late season planted potato crops in Northern Tunisia

“…to the presence of necrotic lesions on tubers making them unmarketable for export, fortunately only on cv Monalisa which is not widely cultivated (BoukhrisBouhachem et al 2008). Recent outbreaks of this disease in the last twelve years have occurred in France (Crouau and Gokelaere 1997), Italy (Tomassoli and Lumia 1998), Greece (Bem and Varveri 1999), Japan (Ohshima et al 2000), Peru (Salazar et al 2000), USA and Canada (Crosslin et al 2002).…”

Potato virus Y: An Evolving Concern for Potato Crops in the United States and Canada

“…1 . PVY NTN isolates were originally named for their ability to cause potato tuber necrosis in addition to tobacco veinal necrosis (2,6,48,65,93). They apparently arose from both recombination (32) and mutation events (45,59).…”

Potato cv. Romano reaction to primary and secondary infection with potato necrotic strain Y virus (PVYNTN)

“…PVY NTN , which belongs to PVY N , only causes symptoms of ringspot necrosis on tubers . PVY N and PVY O have been shown to have recombined to the form PVY NTN that causes PTNR (Boonham et al, 1999(Boonham et al, , 2002Gray et al, 2010;Ohshima et al, 2000;Singh et al, 2008). Subsequent biological characterization of PVY NTN isolates on cvs.…”

“…First symptoms were detected on the Monalisa cultivar in Hungary (Beczner et al, 1984), then in other regions of Europe (Bem et al, 1999;Blanco-Urgoiti et al, 1998;Buturović & Kus, 1989;Kus, 1995;le Romancer & Nedellec, 1997;Serra & Weidemann, 1997), and finally spread worldwide -in North and South America (McDonald & Singh, 1996;Salazar et al, 2000), New Zeland * (Hay, et al, 1989) and Japan (Ohshima et al, 2000).…”