CIRAD, UMR BGPI, 34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France.
CIRAD, UMR BGPI, 34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France.
Virus Res. 2018 Jan 15;244:235-251. doi: 10.1016/j.virusres.2017.11.019. Epub 2017 Nov 21.
Cacao swollen shoot virus is a member of the family Caulimoviridae, genus Badnavirus and is naturally transmitted to Theobroma cacao (L.) by several mealybug species. CSSV populations in West African countries are highly variable and genetically structured into several different groups based on the diversity in the first part of ORF3 which encodes the movement protein. To unravel the extent of isolate diversity and address the problems of low titer and mixed viral sequences in samples, we used Illumina MiSeq and HiSeq technology. We were able to reconstruct de novo 20 new complete genomes from cacao samples collected in the Cocoa Research Institute of Ghana (CRIG) Museum and from the field samples collected in Côte d'Ivoire or Ghana. Based on the 20% threshold of nucleotide divergence in the reverse transcriptase/ribonuclease H (RT/RNase H) region which denotes species demarcation, we conclude there exist seven new species associated with the cacao swollen shoot disease. These new species along with the three already described leads to ten, the total number of the complex of viral species associated with the disease. A sample from Sri Lanka exhibiting similar leaf symptomology to West African CSSD-affected plants was also included in the study and the corresponding sequence represents the genome of a new virus named cacao bacilliform SriLanka virus (CBSLV).
可可肿枝病毒是呼肠孤病毒科、Badnavirus 属的一员,通过几种粉蚧自然传播给可可(Theobroma cacao(L.))。西非国家的 CSSV 群体具有高度的变异性,并根据编码运动蛋白的 ORF3 第一部分的多样性,在遗传上分为几个不同的组。为了阐明分离株多样性的程度,并解决样品中滴度低和混合病毒序列的问题,我们使用了 Illumina MiSeq 和 HiSeq 技术。我们能够从头构建 20 个新的完整基因组,这些基因组来自加纳可可研究所(CRIG)博物馆收集的可可样本和科特迪瓦或加纳田间样本。基于逆转录酶/核糖核酸酶 H(RT/RNase H)区域 20%的核苷酸差异阈值,该阈值表示物种划分,我们得出结论,存在与可可肿枝病相关的七种新物种。这些新物种加上已经描述的三种,总共与该疾病相关的病毒物种有十种。一个来自斯里兰卡的样本表现出与受西非 CSSD 影响的植物相似的叶片症状,也被纳入了研究,相应的序列代表了一种新病毒的基因组,命名为可可杆状斯里兰卡病毒(CBSLV)。