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Bootstrap consensus tree constructed using the neighbor-joining method from 489 bp of ribosomal internal transcribed spacer DNA obtained from the TCM-6 and Septoria population. The tree was rooted to Dividiella tassiana. The isolate TCM-6 are indicated in bold font.
Source publication
A new leaf spot disease was observed on leaves of Rheum palmatum (Chinese rhubarb) in Northwest China (Gansu Province) starting in 2005. A Septoria-like fungus was isolated and completion of Koch's postulates confirmed that the fungus was the casual agent of the leaf spot disease. Morphology and molecular methods were combined to identify the patho...
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Context 1
... were revealed from the analysis. One clade includes S. cucubali (GU214698), S. matthiolae voucher (KM975409), S. create (KF251233), S. lavandulae, S. polygonorum (KF373078), S. polygonorum (KF251505), S. rumicum (KF251529). The other clade includes three strains of Mycosphaerella brassicicola (AF297227, EU167607, and AF297223) and TCM-6 as well (Fig. 3). The strain has high similarity with M. brassicicola, we assume that the sexual stage of TCM-6 is Mycosphaerella ...
Citations
Peach shoot blight (PSB), which kills shoots, newly sprouted leaf buds and peach fruits, has gradually increased over the last ten years and has resulted in 30-50% of the total production loss of the peach industry in China. Phomopsis amygdali has been identified as the common causal agent of this disease. In this study, two new species, Phomopsis liquidambaris (strain JW18-2) and Diaporthe eres (strain JH18-2), were also pathogens causing PSB, as determined through molecular phylogenetic analysis based on the sequences of the internal transcribed spacer region (ITS), translation elongation factor 1-α (EF1-α) and beta-tubulin (TUB), and colony and conidial morphological characteristics. Biological phenotypic analysis showed that the colony growth rate of strain JW18-2 was faster than that of strains JH18-2 and ZN32 (one of the P. amygdali strains that we previously found and identified). All three strains produced α-conidia; however, JW18-2 could not produce β-conidia on alfalfa decoction and Czapek media, and the β-conidia produced by strain JH18-2 were shorter in length and thicker in width than those produced by strain ZN32. Pathogenicity tests showed that JW18-2 presented the strongest pathogenicity for peach fruits and twigs and was followed by strains JH18-2 and ZN32. The results shed light on the etiology of PSB and provide a warning that P. liquidambaris or D. eres might develop into dominant species after a few years, while also potentially benefitting the development of effective disease control management strategies.
Chinese rhubarb (Rheum palmatum) is an important crop that has been used in traditional Chinese medicine for over 2000 years. The main cultivation areas are the Chinese provinces of Gansu, Qinhai, Tibet and Sichuan. Various fungal diseases threaten Chinese rhubarb, the most common of which is leaf smut. In literature, the causal agent of this disease is described as Thecaphora schwarzmaniana. We present morphological data and molecular phylogenetic data of two rDNA loci (ITS1‐5.8S‐ITS2 and 28S D1‐D2) which, however, justify the classification of the causal agent as a distinct species. Here we describe the new species Thecaphora dahuangis for the leaf smut pathogen of Chinese rhubarb.
