Gogile Ashebir, Kebede Misrak, Kidanemariam Dawit, Abraham Adane
Department of Biotechnology, College of Natural and Applied Sciences, Addis Ababa Science and Technology University, P.O.Box 16417, Addis Ababa, Ethiopia.
Department of Biology, College of Natural and Computational Sciences, Wolaita Sodo University, P.O.Box 138, Wolaita Sodo, Ethiopia.
Heliyon. 2024 Feb 15;10(5):e26387. doi: 10.1016/j.heliyon.2024.e26387. eCollection 2024 Mar 15.
Yam ( spp.) is a staple food crop with cultural, nutritional and economic significance for millions of small-scale farmers in sub-Saharan Africa. While various virus-like symptoms such as mosaic and chlorosis are frequently observed in yam fields in Ethiopia, little information is available on the prevalence, distribution, and molecular characteristics of viruses causing these symptoms. The aim of this study was to investigate the incidence and distribution of yam viruses and determine the primary cause of yam mosaic diseases (YMD) in Ethiopia. Both symptomatic (n = 280) and asymptomatic (n = 110) yam leaf samples were collected and tested for potyviruses using ACP-ELISA. In addition, the symptomatic leaf samples were screened for yam mosaic virus (YMV), yam mild mosaic virus (YMMV), and cucumber mosaic virus (CMV) by DAS-ELISA. Subsequently, total RNA was extracted from 130 leaf samples comprising 94 symptomatic and 36 asymptomatic samples representing the different study areas. The representative RT-PCR amplicons (n = 6) were Sanger sequenced. The ACP-ELISA and DAS-ELISA results showed 9.2%, and 12.9% YMV infection, respectively, while the RT-PCR analysis showed 28.5% YMV positivity rate. Both CMV and YMMV were not detected in any of the samples tested. Thus, YMV is confirmed as the primary cause of YMD in Ethiopia. YMV isolates from Ethiopia shared 92-93% nucleotide identity among themselves and 85-99% with other YMV isolates from the GenBank. Phylogenetic analysis revealed that YMV isolates from Ethiopia, South America, and west-central Africa have the most recent common ancestor, while isolates from China and Japan are clustered as sister groups. This study enhances our understanding of YMV's genetic diversity and provides valuable information regarding the first report of YMV in Ethiopia.
薯蓣（薯蓣属物种）是一种主食作物，对撒哈拉以南非洲数百万小规模农户具有文化、营养和经济意义。虽然在埃塞俄比亚的薯蓣田中经常观察到各种类似病毒的症状，如花叶病和黄化病，但关于引起这些症状的病毒的流行情况、分布和分子特征的信息却很少。本研究的目的是调查埃塞俄比亚薯蓣病毒的发病率和分布情况，并确定薯蓣花叶病（YMD）的主要病因。采集了有症状（n = 280）和无症状（n = 110）的薯蓣叶片样本，并用抗黄瓜花叶病毒（ACP）-酶联免疫吸附测定法（ELISA）检测马铃薯Y病毒属病毒。此外，通过双抗夹心ELISA（DAS-ELISA）对有症状的叶片样本进行了山药花叶病毒（YMV）、山药轻花叶病毒（YMMV）和黄瓜花叶病毒（CMV）的筛查。随后，从130个叶片样本中提取了总RNA，这些样本包括94个有症状样本和36个无症状样本，代表了不同的研究区域。对代表性的逆转录-聚合酶链反应（RT-PCR）扩增子（n = 6）进行了桑格测序。ACP-ELISA和DAS-ELISA结果显示，YMV感染率分别为9.2%和12.9%，而RT-PCR分析显示YMV阳性率为28.5%。在所有测试样本中均未检测到CMV和YMMV。因此，YMV被确认为埃塞俄比亚YMD的主要病因。埃塞俄比亚的YMV分离株彼此之间的核苷酸同一性为92%-93%，与GenBank中其他YMV分离株的同一性为85%-99%。系统发育分析表明，来自埃塞俄比亚、南美洲和中西部非洲的YMV分离株有最近的共同祖先，而来自中国和日本的分离株聚为姐妹群。本研究增进了我们对YMV遗传多样性的理解，并提供了关于埃塞俄比亚首次报道YMV的有价值信息。
