ABSTRACT In Oman, vegetable crops, especially tomatoes, have been severely infected by geminivirus disease, with symptoms observed in both the south and north. A comprehensive survey confirmed the presence of Tomato leaf curl diseases (ToLCD), caused by various begomoviruses (family: Geminiviridae ). This study reports the characterisation of viruses isolated from tomato exhibiting ToLCD symptoms in both regions. Forty‐nine sequences of seven viruses (six monopartite and one bipartite begomoviruses) were analysed. The identified viruses include Tomato yellow leaf curl virus ‐Oman (TYLCV‐OM; Begomovirus coheni ), Tomato leaf curl Barka virus (ToLCBrV), Tomato leaf curl Liwa virus (ToLCLwV; Begomovirus solanumliwaense ), Tomato leaf curl Sudan virus ‐Oman (ToLCSDV‐OM; Begomovirus solanumsudanense ), Cotton leaf curl Gezira virus ‐Albatinah (CLCuGeV‐AB; Begomovirus gossypigeziraense ), Chilli leaf curl virus ‐Oman (ChLCV‐OM; Begomovirus chillicapsici ) and Mungbean yellow mosaic India virus (MYMIV; Begomovirus vignaradiataindiaense ). All clones exhibited high nucleotide identity with the corresponding virus isolates reported previously. The ChLCV‐OM clones exhibited 93.54% to 100% nucleotide identity to each other, indicating they belong to the same begomovirus species. Among these, five isolates grouped separately as G1 share 93.54% to 94.08% identity with the remaining 11 isolates grouped as G2. This indicates the occurrence of two strains of ChLCV‐OM in tomato in Oman. Twenty‐one potentially full‐length clones of Tomato leaf curl betasatellite (ToLCB) were also characterised, associated with different ToLCD‐infecting begomoviruses. Notably, ToLCLwV and ToLCSDV‐OM with ToLCB were also reported, which was not the case previously. The phylogenetic analysis results based on viruses and betasatellites formed closed clusters with the respective viruses and the betasatellites. The findings of this study confirm the significance of geminivirus diseases on tomato crop in Oman and highlight the evolving complexity of ToLCD association.
Akhtar et al. (Tue,) studied this question.