Production of discernible disease phenotypes in C anna by five plant viruses belonging to the genera P otyvirus , C ucumovirus and B adnavirus

Cannas are tropical and subtropical flowering perennial plants. The genus contains many species but most commercially grown cultivars are interspecific hybrids selected for their attractive foliage and flowers. Canna production is so lucrative that there are farmers and nurseries dedicated solely to its production. The specific issue that the canna industry faces is virus diseases. In this study, rhizomes of 24 canna cultivars were gathered and diagnostics conducted to detect Bean yellow mosaic virus ( BYMV , Potyvirus ), Canna yellow mottle virus (Ca YMV , Badnavirus ), Canna yellow streak virus (Ca YSV , Potyvirus ), Cucumber mosaic virus ( CMV , Cucumovirus ) and Tomato aspermy virus ( TAV , Cucumovirus ). Visual assessment of disease symptoms and diagnostic tests were carried out to identify the prevalent diseases and describe the symptoms that are associated with virus infection. BYMV , Ca YMV and Ca YSV caused severe mosaic and necrosis either in the leaf lamina or veins of infected leaves. Potyvirus infection suppressed red colouration in the foliage of some varieties. Ca YMV and Ca YSV often appeared in the same plant, suggesting they might represent a viral complex. CMV and TAV were rarely seen in these populations. Interestingly, Ca YMV but not Ca YSV could be mechanically inoculated to P haseolus vulgaris plants.