Comparisons among isolates of Sweet potato feathery mottle virus
using complete genomic RNA sequences
Received: 5 October 2009 / Accepted: 19 January 2010 / Published online: 25 March 2010
Ó Springer-Verlag 2010
Abstract We determined the complete or partial nucleo-
tide sequences of eight Sweet potato feathery mottle virus
(SPFMV) isolates and compared them with 12 other partial
SPFMV sequences. The genome organization of the isolate
Bungo (strain group C) was very different from those of
isolates in the russet crack, ordinary (O), and east Africa
groups. 10-O appeared to be a recombinant of isolates S
and O, with a recombination site within the P1 gene. This
study will help to provide a better understanding of the
taxonomy and biology of SPFMV and how these features
relate to virulence.
Keywords Potyvirus Á Recombination Á Sequence Á
Sweet potato feathery mottle virus (SPFMV) belongs to the
genus Potyvirus  and causes russet crack (RC) and skin
discoloration of the storage roots of sweet potato (Ipomoea
batatas). SPFMV is one of the most damaging viruses that
affect sweet potato worldwide . The partial nucleotide
sequences of 122 SPFMV isolates have been determined
and deposited in the DDBJ/EMBL/GenBank database.
They have been classiﬁed into four distinct strain groups,
RC, ordinary (O), common (C) and east Africa (EA) [5,
15]. To date, ﬁve isolates, S, O, T, 10-O, and Bungo have
been identiﬁed in Japan. S, O, 10-O, and Bungo were
placed in the RC, O, O, and C strain groups, respectively
[16, 17]. The strain group to which T belongs is unknown.
S causes RCs and severe skin discoloration of the roots.
Although O resembles S serologically, it induces only mild
skin discoloration, while infections with T and Bungo are
asymptomatic. The isolate 10-O causes no RCs or obvious
root skin discoloration. Furthermore, 10-O protects I. batatas
plants from S infection by cross-protection .
Studies of the molecular taxonomy of plant viruses
including potyviruses have mostly been done using coat
protein (CP) regions. The SPFMV isolates have been
classiﬁed into strain groups based on their 3
nucleotide sequences, which include the CP genes [5, 15].
Recent studies of mutations and recombination in viruses,
using complete nucleotide sequences, have helped to pro-
vide a better understanding of viral taxonomy and the
biological properties of viruses . These studies are
The nucleotide sequence will appear in the DDBJ, EMBL, and
GenBank nucleotide sequence databases under the accession number
AB439206, AB465608, AB509453, AB509455, AB509456,
AB509457, AB509458, AB509459, AB509460, AB509461,
AB509462, AB509463 and AB509464.
Electronic supplementary material The online version of this
article (doi:10.1007/s00705-010-0633-0) contains supplementary
material, which is available to authorized users.
S. Yamasaki (&) Á S. Kamisoyama Á K. Emoto
Oita Prefectural Agriculture, Forestry and Fisheries Research
Center, Kitausa, Usa, Oita 872-0103, Japan
National Agricultural Research Center for Tohoku Region,
Faculty of Bioresource Sciences, Akita Prefectural University,
Faculty of Agriculture, Saga University, Saga, Japan
National Agricultural Research Center, Ibaraki, Japan
Arch Virol (2010) 155:795–800