Tairo F, Mbewe W K, Mark D, Lupembe M, Sseruwagi P, Ndunguru J
Mikocheni Agricultural Research Institute, P.O Box 6226, Dar es Salaam, Tanzania.
School of Agricultural Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
Afr J Biotechnol. 2017;16(36). doi: 10.5897/AJB2017.16130. Epub 2017 Sep 6.
subsp. (Müll.Arg.) Allem., a wild relative of cassava, native to Brazil, is one of the popular agroforestry trees used for hedges and/or boundary plants surrounding homesteads and farms and also harbours cassava mosaic begomoviruses (CMBs) and cassava brown streak ipomoviruses. Sequences of the DNA-A component of (EACMV) isolates from subsp. (Müll.Arg.) Allem., collected from non-cassava growing areas of Tanzania were characterized. Thirteen full length DNA-A sequences were analysed together with 15 already reported EACMV sequences and six CMB species reference genomes. The results show 96 to 100% nucleotide sequence identity with EACMV isolates from Kenya. Phylogenetic analysis revealed that EACMV isolates from subsp. Müll.Arg.) Allem, belong to a single cassava mosaic begomovirus species. The EACMV monophyletic clade is distinct from all other CMB species. The presence of Cassava infecting begomoviruses in wild cassava relative growing from traditionally non cassava growing region serve as inoculum sources for cassava-infecting begomoviruses and therefore their eradication is key in the sustainable management of CMBs, especially in the non-cassava growing areas.
亚种（Müll.Arg.）Allem. 是木薯的野生近缘种，原产于巴西，是用于家园和农场周围树篱和/或边界植物的常见农林树木之一，并且还携带木薯花叶双生病毒（CMB）和木薯褐色条纹甘薯病毒。对从坦桑尼亚非木薯种植区采集的亚种（Müll.Arg.）Allem. 的东非木薯花叶病毒（EACMV）分离株的DNA-A 组分序列进行了特征分析。将13个全长DNA-A 序列与15个已报道的EACMV序列以及6个CMB物种参考基因组一起进行了分析。结果显示与来自肯尼亚的EACMV分离株具有96%至100%的核苷酸序列同一性。系统发育分析表明，来自亚种（Müll.Arg.）Allem. 的EACMV分离株属于单一的木薯花叶双生病毒物种。EACMV单系分支与所有其他CMB物种不同。在传统非木薯种植区生长的野生木薯近缘种中存在感染木薯的双生病毒，这是感染木薯的双生病毒的接种源，因此根除它们是CMB可持续管理的关键，特别是在非木薯种植区。
