Symptoms and pathogens diversity of Corn Fusarium sheath rot in Sichuan Province, China

• Published in: Scientific reports Vol. 11; no. 1; p. 2835
• Main Authors: Wang, Wei, Wang, Bo, Sun, Xiaofang, Qi, Xiaobo, Zhao, Conghao, Chang, Xiaoli, Khaskheli, Muhammad Ibrahim, Gong, Guoshu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.02.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326; 692/699; China; Corn; Fusarium; Fusarium - genetics; Fusarium - isolation & purification; Fusarium - pathogenicity; Humanities and Social Sciences; Mixed infection; multidisciplinary; Pathogenicity; Pathogens; Phylogeny; Physical characteristics; Plant Diseases - microbiology; Science; Science (multidisciplinary); Species; Virulence; Zea mays - microbiology; China
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-82463-2

To elucidate the symptoms and pathogens diversity of corn Fusarium sheath rot (CFSR), diseased samples were collected from 21 county-level regions in 12 prefecture-level districts of Sichuan Province from 2015 to 2018 in the present study. In the field, two symptom types appeared including small black spots with a linear distribution and wet blotches with a tawny or brown color. One hundred thirty-seven Fusarium isolates were identified based on morphological characteristics and phylogenetic analysis ( EF1-α ), and Koch’s postulates were also assessed. The results identified the isolates as 8 species in the Fusarium genus, including F. verticillioides , F. proliferatum , F. fujikuroi , F. asiaticum , F. equiseti , F. meridionale , F. graminearum and F. oxysporum , with isolation frequencies of 30.00, 22.67, 15.33, 7.33, 6.00, 5.33, 3.33 and 1.33%, respectively. Fusarium verticillioides and F. proliferatum were the dominant and subdominant species, respectively. Two or more Fusarium species such as F. verticillioides and F. proliferatum were simultaneously identified at a mixed infection rate of 14.67% in the present study. The pathogenicity test results showed that F. proliferatum and F. fujikuroi exhibited the highest virulence, with average disease indices of 30.28 ± 2.87 and 28.06 ± 1.96, followed by F. equiseti and F. verticillioides , with disease indices of 21.48 ± 2.14 and 16.21 ± 1.84, respectively. Fusarium asiaticum , F. graminearum and F. meridonale showed lower virulence, with disease indices of 13.80 ± 2.07, 11.57 ± 2.40 and 13.89 ± 2.49, respectively. Finally, F. orysporum presented the lowest virulence in CFSR, with a disease index of 10.14 ± 1.20. To the best of our knowledge, this is the first report of F. fujikuroi , F. meridionale and F. asiaticum as CFSR pathogens in China.