Chauhan Ravendra P, Hamon Hayden F, Rajakaruna Punsasi, Webb Mark A, Payton Mark, Verchot Jeanmarie
Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater 74078.
Department of Statistics, Oklahoma State University, Stillwater 74078.
Plant Dis. 2015 Feb;99(2):188-194. doi: 10.1094/PDIS-05-14-0538-RE.
Cannas grow from rhizomes to produce colorful foliage that ranges from deep burgundy, bronze, green, purple veined, and variegated. Bean yellow mosaic virus (BYMV), Canna yellow streak virus (CaYSV), and Canna yellow mottle virus (CaYMV) are problematic viruses infecting cannas. Their disease characteristics have been reported in green-leaved varieties. This study investigated if rhizome planting stocks can be a source of virus infection. PCR and RT-PCR tests identified BYMV, CaYSV, and CaYMV sequences in 20 canna rhizomes and newly emerging leaves. Immunosorbent electron microscopy tests identified filamentous potyvirus particles in rhizome and leaf tissue. In addition, disease characteristics were examined in a subset of red-leaved varieties 'Australia', 'Burning Ember', and 'Red Futurity' planted in pots in the greenhouse. Plants were assigned identifying codes, visual disease ratings, and samples were taken for RT-PCR and PCR virus detection assays. Statistical analysis was carried out to compare disease ratings with RT-PCR and PCR test results. Visual assessment was found to be not a reliable indicator of virus infection in 'Australia' and 'Burning Ember' plants. 'Red Futurity' produced the most obvious pattern of mosaic disease and virus symptoms were easier to identify in this variety. This study demonstrated that visual assessment was an ineffective method for disease identification for the red-leaved varieties. Growers would be well advised to utilize molecular testing to identify infected plants to aid in the clean-up of the crop.
美人蕉从根茎生长而来，能长出色彩斑斓的叶子，颜色范围从深紫红色、青铜色、绿色、带紫色叶脉到杂色。菜豆黄花叶病毒（BYMV）、美人蕉黄条病毒（CaYSV）和美人蕉黄斑病毒（CaYMV）是感染美人蕉的有问题的病毒。它们的病害特征已在绿叶品种中有所报道。本研究调查了根茎种植材料是否会成为病毒感染源。PCR和RT-PCR检测在20个美人蕉根茎和新长出的叶子中鉴定出了BYMV、CaYSV和CaYMV序列。免疫吸附电子显微镜检测在根茎和叶片组织中鉴定出丝状马铃薯Y病毒颗粒。此外，还对种植在温室花盆中的红叶品种‘澳大利亚’、‘燃烧的余烬’和‘红色未来’的一个子集进行了病害特征检查。给植株分配了识别代码、视觉病害评级，并采集样本进行RT-PCR和PCR病毒检测分析。进行了统计分析以比较病害评级与RT-PCR和PCR检测结果。结果发现，视觉评估在‘澳大利亚’和‘燃烧的余烬’植株中不是病毒感染的可靠指标。‘红色未来’出现了最明显的花叶病模式，且该品种的病毒症状更容易识别。本研究表明，视觉评估对于红叶品种的病害鉴定是一种无效方法。建议种植者利用分子检测来识别受感染植株，以帮助清理作物。
