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Bean yellow mosaic virus (BYMV, Potyvirus, Potyviridae) causes serious disease in Gladiolus spp. In this work, the possibility of obtaining BYMV free plant material from virus infected gladiolus corms was studied. Thermotherapy, meristem-tip culture and combination of both techniques on infected corms/meristem-tip explants (0.5–1 mm in length) resulted in BYMV elimination up to 15.38, 78.04 and 86.66%, respectively, as determined by double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) and reverse transcription-polymerase chain reaction (IC-RT-PCR). Individual virus-free shoots readily rooted in vitro and were transferred to corm formation medium. The results showed that thermotherapy promotes the survival rate of explants during meristem-tip culture steps (except regeneration step) and also plantlet acclimatization. Statistical analysis showed that the BYMV elimination in gladiolus corms was significantly (P ≤ 0.01) affected by thermotherapy treatment of infected corms. Thermotherapy combined with meristem culture can greatly improve BYMV elimination efficiency from infected gladiolus corms, resulting in the production of BYMV free gladiolus plants.

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Cucumber mosaic virus (CMV; genus Cucumovirus, family: Bromoviridae) has the widest host range of any known plant viruses. Seven virus isolates, originated from different ornamental plant species and greenhouses, were biologically purified, mechanically inoculated onto test plants and their serological differences were assayed based on reactivity with 11 CMV-specific monoclonal antibodies. Following total RNA extraction, coat protein (CP) coding region of CMV isolates was amplified. Based on biological, serological and phylogenetic analysis, only one isolate belonged to CMV subgroup II and other six isolates were equally distributed among the two IA and IB subgroups. Aphid transmission assay showed that no significant difference was observed between transmission efficiency of CMV subgroups IA, IB and II members by Aphis gossypii. The genetic variation and evolution of CMV in Iran was studied by sequence analysis of the CP gene and comparison with equivalent sequences of isolates from other continents that exhibited low genetic diversity and close evolutionary relationships among isolates in subpopulations. Analysis of various population genetics parameters and distribution of synonymous and nonsynonymous mutations revealed that most of the amino acid sites were under negative selection and only one site was under positive selection.