Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan.
Master Program for Plant Medicine and Good Agricultural Practice, National Chung Hsing University, Taichung 402, Taiwan.
Plant Dis. 2023 Oct;107(10):3222-3229. doi: 10.1094/PDIS-10-22-2338-RE. Epub 2023 Oct 23.
species cause algal spot diseases, also known as red rust diseases, on many plants, including fruit crops. Most algal species are defined based on their morphological characteristics. Recent phylogenetic studies of species showed that morphological determination was not congruent with phylogeny. Our study examined the phylogenetic congruence of the host invasion types (or growth habits), which are the most critical characteristics in the taxonomy of . To ensure that host invasion types and phylogenetic characteristics could be inferred from the same isolate, host invasion types were assessed using microanatomical observation, and rRNA sequences from the same algal spot and/or the derived algal cultures were compared. Host invasion types were found to be conserved classification traits and were congruent with phylogeny. The results also indicated that more than one species commonly grew on the same leaf or, in a few cases, the same algal spot, suggesting that identification using different algal spots could result in misidentification. The isolates were separated into two species complexes by host invasion types: the species complex (CVSC) with subcuticular host invasion type and the species complex (CPSC) with intercellular host invasion type. Molecular phylogenetic analysis indicated that isolates clustered into 14 clades of CVSC and three clades of CPSC. This study also identified 16 and eight new hosts of CVSC and CPSC in Taiwan, respectively.
物种会引起许多植物的藻斑病，也称为红锈病，包括水果作物。大多数藻类物种是根据其形态特征来定义的。最近对物种的系统发育研究表明，形态学鉴定与系统发育不一致。本研究检查了宿主入侵类型（或生长习性）的系统发育一致性，这是分类学中最关键的特征。为了确保可以从同一分离株推断出宿主入侵类型和系统发育特征，使用微观解剖观察评估了宿主入侵类型，并比较了来自同一藻斑和/或衍生藻培养物的 rRNA 序列。结果发现，宿主入侵类型是保守的分类特征，与系统发育一致。结果还表明，一种以上的物种通常在同一叶片上生长，或者在少数情况下，在同一藻斑上生长，这表明使用不同的藻斑进行鉴定可能会导致误鉴定。根据宿主入侵类型，将分离株分为两个物种复合体：具有次生表皮下宿主入侵类型的物种复合体（CVSC）和具有细胞间宿主入侵类型的物种复合体（CPSC）。分子系统发育分析表明，分离株聚类为 14 个 CVSC 分支和 3 个 CPSC 分支。本研究还在台湾分别鉴定出 CVSC 和 CPSC 的 16 个和 8 个新宿主。
