Molecular diversity of ecologically distinct Mal de Río Cuarto virus isolates based on restriction fragment length polymorphism (RFLPs) and genome sequence analysis of segments 1, 7, 9 and 10

Abstract

Viruses of the species Mal de Río Cuarto virus (genus Fijivirus, family Reoviridae) cause significant economic losses in maize in Argentina. Genetic changes in the virus genome leading to better adaptation to diverse ecological conditions were postulated that would account for the increasing MRCV variability. The genomic differences between MRCV isolates from four ecologically different areas (Río Cuarto, RC; Pergamino, P; Jesús María, JM; and Tafí del Valle, TV) were studied. RT-PCR-amplified fragments comprising four genomic segments (Seg1, Seg7, Seg9 and Seg10) of MRCV isolates were compared by RFLPs and nucleotide sequences. The segments were chosen based on the proteins they encode: RNA-dependent-RNA polymerase, proteins putatively associated with tubular structures and viroplasm and the major outer capsid protein, respectively. Genetic comparison suggested that JM and TV isolates were genetically similar, but RC and P were different. Therefore, they were clustered in three genetic groups (JM = TV, RC and P). Together, nucleotide and amino acid sequence identities of the genomic segments were often above 96%. Seg1 was more variable (viral polymerase), whereas Seg7 (putative tubular structure) was the most conserved. Phylogeny analysis showed that MRCV isolates could be clustered in 'mountain area' and 'high production area' groups according to their geographical occurrence.

The Complete Genome Sequence of Two Isolates of Southern rice black‐streaked dwarf virus, a New Member of the Genus Fijivirus

“…2003). Four MRCV isolates from different regions in Argentina shared over 96% nucleotide identity (Giménez‐Pecci et al. 2007), and 25 FDV isolates from Australia, Papua New Guinea and Malaysia had more than 85% nucleotide identity (Jiang et al.…”

“…Thus, sequences of rice and maize RBSDV isolates from different geographical regions show more than 90% nucleotide identity (Zhang et al 2001a,b;Wang et al 2003). Four MRCV isolates from different regions in Argentina shared over 96% nucleotide identity (Gime´nez-Pecci et al 2007), and 25 FDV isolates from Australia, Papua New Guinea and Malaysia had more than 85% nucleotide identity (Jiang et al 2008). In addition, we recently sequenced the partial outer capsid protein gene of more than 100 SRBSDV isolates from different areas in China and Vietnam and found that the sequences were over 97% nucleotide identical (unpublished data).…”

呼肠孤病毒科斐济病毒属一新种: 南方水稻黑条矮缩病毒

“…dsRNA , GenBank RBSDV , S9 S10 90%( 4 7); , Giménez-Pecci [22] 4 MRCV S1, S7, S9 S10 , 96%; Jiang [23] 25 FDV…”