Diversity Among Potato virus Y Isolates Obtained from Potatoes Grown in the United States

Abstract

Potato field isolates (Solanum tuberosum) of Potato virus Y (PVY) collected from the midwestern and western United States were characterized using serological, molecular, and biological assays. PVY field isolates were grouped into the previously defined categories: PVY(O), European PVY(NTN), North American PVY(NTN), and PVY(N:O) recombinant and four previously undefined groups. Studies reported here agree with published reports from Europe and elsewhere in North America as PVY isolates capable of causing veinal necrosis in tobacco indicator plants appear in high frequency. In contrast to European experiences, PVY tuber necrosis isolates have a PVY(O) coat protein rather than that of PVY(N). Several PVY(N:O) recombinant isolates induced potato tuber necrotic ringspot disease (PTNRD) in the highly susceptible potato cv. Yukon Gold. The PTNRD symptoms produced by these PVY(N:O) recombinants were atypical compared with lesions found on the same cultivar infected with either the European or North American PVY(NTN) isolates. These PVY(N:O) isolates produced a roughly circular, sunken necrotic lesion on the surface of the tuber instead of the typical external sunken ring pattern displayed by PVY(NTN) isolates. This study establishes the complex nature of PVY populations within the U.S. potato industry and clearly demonstrates the diverse nature of PVY in the United States.

Physiological and Infectious Characters of Potato virus Y-Egyptian isolate

“…white burly. The observed typical external symptoms were leaf crinkle, mottling severe mosaic and stunting meanwhile, Piche et al (2004) reported that, 58 PVY field isolates transmitted to tobacco, 11 isolates produced a mild mosaic symptom and the remaining 47 field isolates induced varying degrees of leaf necrosis including venial necrosis, severe stunting and leaf death. An Indian PVY o common strain isolated from field-grown potato plants was maintained in N. glutinosa in an insect-free green-house (Gawande et al, 2011).…”

“…P1 gene, and known recombination junction sites of the PVY genome has led to the separation of isolates recovered from Europe from those isolated in North America (Piche et al, 2004 The Egyptian PVY isolate was clearly classified within group I and was more closely related to PVY NTN strains. Ten nucleotide substitutions resulted in 3 conserved amino acid substitutions resulted in 3 conserved amino acid substitutions (V 1 ® I, G 7 ® E, M or V and S 8 ® G) and were able to differentiate between both groups.…”

Ocorrência de vírus em batata em sete estados do Brasil

“…A primeira descrição da ocorrência desses subgrupos foi feita há mais de duas décadas, na Hungria (Beczner et al, 1984). Posteriormente sua ocorrên-cia foi relatada em vários outros países da Europa (Alemanha, Áustria, Bélgica, Dinamarca, França, Holanda, Polônia) (Beczner et al, 1984;Kerlan & Le Romancer, 1992;Kus;Steinbach & Hamann, 1989;van den Heuvel et al, 1994), no Líbano (Le Romancer et al, 1994), na América do Norte (Piche et al, 2004;Nie et al, 2004) e Japão (Oshima et al, 2000).…”

“…PVY NTN pode induzir sintomas nos tubérculos de batata (Souza-Dias, 2001) na forma de anéis, letras e números, embora nem sempre exista uma associação direta, pois os tubérculos infectados podem permanecer assintomáticos (Singh et al, 2008). Sabe-se que o armazenamento de tubérculo-semente em câmara fria é um fator que aumenta a incidência dos sintomas em tubérculos (Fonseca, 2003 (Piche et al, 2004;Nie et al, 2004;Singh et al, 2008).…”

“…Com relação ao vírus, a virulência dos isolados associada à alta concentração viral em muito favorece o surgimento de novos recombinantes (Nie et al, 2004). Adicionalmente, os sintomas causados pela estirpe necrótica na batatateira são mais brandos que aqueles causados por PVY O e podem passar despercebidos a campo.…”