West Africa Centre for Crop Improvement (WACCI), College of Basic and Applied Sciences, University of Ghana, PMB 30, Legon, Accra, Ghana; National Agricultural Research Organisation (NARO), Buginyanya Zonal Agricultural Research and Development Institute, P. O. Box 1356, Mbale, Uganda.
Council for Scientific and Industrial Research - Crops Research Institute (CSIR- CRI), Fumesua, P. O. Box 3785, Kumasi, Ghana; Department of Plant Resources Development, CSIR College of Science and Technology, Fumesua, Kumasi, Ghana.
Virus Res. 2023 May;329:199106. doi: 10.1016/j.virusres.2023.199106. Epub 2023 Mar 30.
Rice yellow mottle virus (RYMV) has persisted as a major biotic constraint to rice production in Africa. However, no data on RYMV epidemics were available in Ghana, although it is an intensive rice-producing country. Surveys were performed from 2010 to 2020 in eleven rice-growing regions of Ghana. Symptom observations and serological detections confirmed that RYMV is circulating in most of these regions. Coat protein gene and complete genome sequencings revealed that RYMV in Ghana almost exclusively belongs to the strain S2, one of the strains covering the largest area in West Africa. We also detected the presence of the S1ca strain which is being reported for the first time outside its area of origin. These results suggested a complex epidemiological history of RYMV in Ghana and a recent expansion of S1ca to West Africa. Phylogeographic analyses reconstructed at least five independent RYMV introductions in Ghana for the last 40 years, probably due to rice cultivation intensification in West Africa leading to a better circulation of RYMV. In addition to identifying some routes of RYMV dispersion in Ghana, this study contributes to the epidemiological surveillance of RYMV and helps to design disease management strategies, especially through breeding for rice disease resistance.
稻黄花叶病毒（RYMV）一直是非洲水稻生产的主要生物限制因素。然而，尽管加纳是一个水稻种植密集的国家，但加纳没有关于 RYMV 流行的数据。我们于 2010 年至 2020 年在加纳的 11 个水稻种植区进行了调查。症状观察和血清学检测证实，RYMV 在这些地区的大部分地区都有传播。外壳蛋白基因和全基因组测序显示，加纳的 RYMV 几乎完全属于 S2 株，这是在西非分布面积最大的株系之一。我们还检测到了 S1ca 株的存在，这是该株系首次在其起源地以外的地区被发现。这些结果表明，RYMV 在加纳存在复杂的流行历史，以及 S1ca 株最近向西非的扩张。系统发育分析重建了过去 40 年里加纳至少有 5 次独立的 RYMV 传入，这可能是由于西非水稻种植的集约化，导致 RYMV 的传播更好。除了确定 RYMV 在加纳的一些传播途径外，本研究还有助于 RYMV 的流行病学监测，并有助于制定疾病管理策略，特别是通过培育水稻抗病性。
