Abstract:
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.
摘要:
水稻黄斑驳病毒(RYMV)一直是非洲水稻生产的主要生物限制因素。然而,加纳没有关于RYMV流行病的数据,尽管它是一个密集的水稻生产国家。调查于2010年至2020年在加纳的11个水稻种植区进行。症状观察和血清学检测证实RYMV在大多数这些区域中循环。外壳蛋白基因和完整的基因组测序显示,加纳的RYMV几乎完全属于S2菌株,这是覆盖西非面积最大的菌株之一。我们还检测到S1ca菌株的存在,这是首次在其起源区域之外进行报道。这些结果表明,加纳的RYMV具有复杂的流行病学史,并且最近将S1ca扩展到了西非。在过去的40年中,系统地理分析在加纳重建了至少五个独立的RYMV介绍,可能是由于西非水稻种植的集约化导致了RYMV的更好流通。除了确定加纳RYMV分散的一些途径外,这项研究有助于RYMV的流行病学监测,并有助于设计疾病管理策略,特别是通过水稻抗病育种。