Curvularia verruculosa as new causal pathogen of common bean leaf spot disease in China. (December 2022)

• Record Type: Journal Article
• Authors: Wei, Tianpeng; Luo, Mingyan; Zhang, Hong; Jia, Weiyu; Zeng, Yan; Jiang, Yulan
• Is Part Of: Crop protection. Volume 162(2022)
• Publication Date: 2022-12
• Subjects: Common bean -- Curvularia verruculosa -- Leaf spot -- Pathogenicity; Plants, Protection of -- Periodicals; 632.05
• DOI: 10.1016/j.cropro.2022.106091
• Languages: English
• ISSNs: 0261-2194

Abstract

Abstract: Common bean is extensively grown and consumed worldwide and it is considered a nutraceutical food and an important source of protein. Leaf spot is one of the most devastating diseases of common bean in tropical and subtropical production areas. In May 2021, this destructive disease was observed in the Guizhou Province of China and resulted in serious economic losses for local agricultural production. Foliar symptoms appeared as small circular tan-colored spots, which then turned dark brown and coalesced into irregular water-soaked necrotic lesions, often leading to leaf wilt or abscission. Fungal isolates were obtained from symptomatic common bean plants and a detailed morphological analysis was performed. Concatenated phylogenetic reconstruction was conducted by amplifying and sequencing the internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase ( gapdh ) and translation elongation factor 1-alpha ( tef1-α ) genes. Based on morphological characters and phylogenetic analyses, the pathogen was identified as Curvularia verruculosa . In addition, the pathogenicity tests of the isolates reproduced the same symptoms as those observed in the field, and Koch's postulates were confirmed by pathogen re-isolation and identification. To our knowledge, this is the first report of C. verruculosa causing leaf spot on common bean in the world. The current study can provide a foundation for developing effective management strategies, and reducing economic losses in common bean production. Highlights: The occurrence of leaf spot of common bean was observed in Guizhou Province, China. Pathogen diagnosis was based on morphology and multi-locus phylogenetic analyses. Koch's postulates proved the association of C. verruculosa with common bean leaf spot. First report of C. verruculosa as the causal pathogen of leaf spot on common bean. This study contributes to establish the control strategies for common bean diseases.