Phylogenetic and Morphological Identification of the Novel Pathogen of Rheum palmatum Leaf Spot in Gansu, China.
10.5941/MYCO.2016.44.2.93
- Author:
Yan WANG
1
;
Amy O CHARKOWSKI
;
Cuiyun ZENG
;
Tiantian ZHU
;
Huizhen WANG
;
Honggang CHEN
Author Information
1. Gansu University of Chinese Medicine, Lanzhou 730000, China. gswangyan101@163.com
- Publication Type:Original Article
- Keywords:
Internal transcribed spacer rDNA;
Novel pathogen;
Rheum palmatum;
Taxonomy
- MeSH:
China*;
Classification;
Fungi;
Plants;
Polygonaceae;
Rheum*;
Spores, Fungal
- From:Mycobiology
2016;44(2):93-98
- CountryRepublic of Korea
- Language:English
-
Abstract:
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 pathogen. The fungus produced conidiomata pycnidia and the conidia were 2~5 septate, 61.2~134.1 µm in length and 3.53~5.3 µm in width, which is much larger than the known Spetoria species that infects Polygonaceae species. Phylogenic analysis of the internal transcribed spacer region confirmed that this Spetoria-like fungus is within the Spetoria genus but distinct from known Spetoria species. Together, these morphological and phylogenetic data support that the R. palmatum infecting Spetoria strain is a newly-described plant pathogenic species.
