AUTHOR=Gou Ya-Nan , Aung Sein Lai Lai , Htun Aye Aye , Huang Cheng-Xin , Deng Jian-Xin 

TITLE=Alternaria species in section Alternaria associated with Iris plants in China

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1036950

DOI=10.3389/fmicb.2022.1036950

ISSN=1664-302X

ABSTRACT=<p>Plants of the <italic>Iris</italic> genus have been widely cultivated because of their medicinal, ornamental, and economic values. It commonly suffers from <italic>Alternaria</italic> leaf spot or blight disease leading to considerable losses for their commercial values. During an investigation of 14 provinces or municipalities of China from 2014 to 2022, a total of 122 <italic>Alternaria</italic> strains in section <italic>Alternaria</italic> were obtained from diseased leaves of <italic>Iris</italic> spp.. Among them, 12 representative strains were selected and identified based on morphological characterization and multi-locus phylogenetic analysis, which encompassed the internal transcribed spacer of rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (<italic>GAPDH</italic>), translation elongation factor 1 alpha (<italic>TEF1</italic>), RNA polymerase second largest subunit (<italic>RPB2</italic>), <italic>Alternaria</italic> major allergen gene (<italic>Alt a 1</italic>), an anonymous gene region (OPA10-2), and endopolygalacturonase gene (<italic>EndoPG</italic>). The strains comprised two known species of <italic>A. alternata</italic> and <italic>A. iridicola</italic>, and two new species of <italic>A. setosae</italic> and <italic>A. tectorum</italic>, which were described and illustrated here. Their pathogenicity evaluated on <italic>Iris setosa</italic> indicated that all the strains could induce typical <italic>Alternaria</italic> leaf spot or blight symptoms. The results showed that the virulence was variable among those four species, from which <italic>A. tectorum</italic> sp. nov. was the most virulent one, followed by <italic>A. setosae</italic> sp. nov., <italic>A. iridicola</italic> and <italic>A. alternata</italic>.</p>