Abstract
Yellow mosaic disease is a major limiting factor for jute (Corchorus capsularis L.)
cultivation in Bangladesh. We have cloned and sequenced three isolates of Corchorus
golden mosaic virus (CoGMV) collected from different regions in Bangladesh. DNA A
sequence of CoGMV-[BD:Mym:10] (BD1) shared highest identity (94.2%) with the
Vietnam isolate of CoGMV, whereas DNA B shared a lower level of sequence identity
(<73%) with the CoGMV isolates reported from Vietnam and India. Complete genome
sequences of CoGMV-[BD:Ran:10] (BD2) and CoGMV-[BD:Din:10] (BD3) showed at
least 97% sequence identity with Indian isolates of CoGMV. The fact that the examined
DNA A components of three isolates of CoGMV lack the AV2 open reading frame,
indicated that BD1-3 share genetic features of New World begomoviruses. The
pathogenicity of CoGMV-[BD:Din:10] (BD3) isolate was confirmed by agroinoculation
and infectious clones of DNA A and DNA B induced characteristic yellow mosaic
symptoms in jute plants. This is a first experimental demonstration of Koch's postulate
for a begomovirus associated with jute yellow mosaic disease. In situ hybridization
was used to analyze the distribution pattern of Corchorus golden mosaic virus (CoGMV)
CoGMV-[BD:Din:10] in jute plants. When CoGMV was inoculated onto the leaf petiole
of a plant, it replicated and trafficked to sink. CoGMV was absent from shoot apical
meristems. In the flowers of infected plants, CoGMV was present in the sepals, petals,
stamens and ovary. The replicative form of CoGMV was detected in the phloem and
seeds. Tomato leaf curl virus (ToLCV) has emerged as serious problem for tomato in the
recent past, frequently in tropical and subtropical region of the world. Here, we have
identified and characterized two isolates of tomato leaf curl virus (ToLCV) responsible
for the leaf curl disease of tomato in Bangladesh. The complete genome sequences of
ToLCV-[BD:Mym:11] and ToLCV-[BD:Mym2:11] shared the highest nucleotide
sequence identities at 95.04 and 92.38 %, respectively, with Indian isolate of ToLCRaV
and ToLCPaV-[Tob]. Complete nucleotide sequence analysis of two betasatellite clones
(one each from (ToLCV-[BD:Mym:11] and (ToLCV-[BD:Mym2:11]) in BLAST search
revealed 95.51 and 86.30% identity with ToLCBB and ToLCPaB, respectively.