Yellowing of leaf tissue and strongly deformed shoots were observed in common mugwort (Artemisia vulgaris L.) growing in a nature reserve in Southern Poland. Similar foliage chlorosis together with abnormal shoot proliferation was noticed on alder tree (Alnus glutinosa Gaertn.) growing next to the common mugwort. DNA specific fragments coding 16S rRNA and ribosomal proteins (rp) were amplified from mugwort and alder samples using direct and nested PCR (Polymerase Chain Reaction) assays. Phylogenetic relationships inferred from 16S and rps3 genes indicated that strains infecting mugwort and alder were most closely related to phytoplasmas of subgroups 16SrV‐C and 16SrV‐D. Based on the restriction fragment length polymorphism (RFLP) analysis of the 16S rDNA, the investigated phytoplasma strains were classified to subgroup 16SrV‐C. Two sequence variants of the rps3 gene which differed by a single nucleotide were detected in all analysed samples by pairwise analysis of the aligned reads. Taking into account that this single‐nucleotide polymorphism (SNP) occurs among 16SrV‐C and 16SrV‐D related phytoplasmas and that the phytoplasmas have a single copy of rp operon, we concluded that each plant species was infected by two distinct, closely related phytoplasma strains. To the best of our knowledge, this is the first report of group 16SrV‐C related phytoplasmas infecting common mugwort worldwide, adding a new host species that is possibly linked to the spread of the alder pathogen in Eastern Europe. Although alder yellows phytoplasma has been frequently found in Europe, this is the first detection of phytoplasmas associated with alder in Poland.

中文翻译：

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寻常蒿（Artemisia vulgaris）是感染波兰黑al木的16SrV-C植物质体相关菌株的新宿主

在波兰南部自然保护区生长的普通艾蒿（艾蒿）中，观察到叶片组织发黄并严重变形。在常见艾蒿旁边生长的al木（Alnus glutinosa Gaertn。）上也观察到类似的叶子萎黄和异常的芽增殖。使用直接和巢式PCR（聚合酶链反应）分析从艾蒿和mug木样品中扩增出编码16S rRNA和核糖体蛋白（rp）的DNA特异性片段。从16S和rps3推断系统发生关系基因表明感染艾蒿和al木的菌株与亚群16SrV-C和16SrV-D的植原体关系最密切。根据16S rDNA的限制性片段长度多态性（RFLP）分析，将所研究的植物原浆菌株分类为16SrV-C亚组。rps3的两个序列变体通过对比对的读数进行成对分析，在所有分析的样品中检测到仅一个核苷酸不同的基因。考虑到这种单核苷酸多态性（SNP）发生在16SrV‐C和16SrV‐D相关的植物质浆中，并且该植物质浆具有rp操纵子的单个副本，因此我们得出结论，每种植物物种都感染了两种截然不同，密切相关的植物质浆株。据我们所知，这是第16SrV‐C组相关植物质体感染全球普通艾蒿的第一份报告，并增加了一种新的寄主物种，该物种可能与东欧der木病原体的传播有关。尽管在欧洲经常发现al木黄色植物质体，但这是波兰首次发现与al木相关的植物质体。