Molecular Characterization and Pathogenicity Analysis of Alternaria alternata Associated with Leaf Spot Disease of Toona sinensis in China
Year: 2025
Type: article
Abstract: The tree species of Toona sinensis has been cultivated in China for over 2,000 years with multiple purposes. In 2022, leaf spots were detected on the leaves of T. sinensis in a germplasm resource nursery in Zhejiang Province, China. Symptomatic leaves were collected and fungal isolation was conducted. Four fungal isolates resembling Alternaria were isolated from the diseased leaves. These isolates were identified as Alternaria alternata, combining the morphological characteristics and multigene phylogenetic analysis. To fulfill Koch’s postulates, pathogenicity of the selected isolate YKHH was tested on 2-year-old container seedlings of T. sinensis. Disease symptoms basi-cally consistent with those observed in the field developed 12 days after inoculation (DAI) when either conidia or mycelia were used as the inoculum. Nevertheless, no visible symptoms devel-oped on the leaves of the control groups. The fungi were reisolated from the diseased leaves, and both the morphological characteristics as well as the three gene sequences (GAPDH, RPB2, and TEF1-α) of the reisolated fungi were consistent with those of the original YKHH isolate. Suscepti-bility trial results showed that family 55 of T. sinensis (F55) had the highest susceptibility to A. al-ternata, while family 28 of T. sinensis (F28), family 52 of T. sinensis (F52), and Toona ciliata var. pu-bescens (TCP) exhibited equal susceptibility to A. alternata. To the best of our knowledge, this is the first report of leaf spot disease caused by A. alternata on T. sinensis in China.
Source: Horticulturae
Authors: Xiansheng Geng, Huyun Mvchir, Jun Liu, Keda Hua, Qiang Miu, Jinping Shu
Language: English
Subfield: Cell Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $2,654
Funder: Chinese Academy of Forestry
OpenAlex ID: W4408219511