Publication Date:
2024-03-06
Description:
Species in Diaporthe have broad host ranges and cosmopolitan geographic distributions, occurring as
\nendophytes, saprobes and plant pathogens. Previous studies have indicated that many Diaporthe species are associated with Citrus. To further determine the diversity of Diaporthe species associated with citrus diseases in China,
\nwe conducted extensive surveys in major citrus-producing areas from 2017\xe2\x80\x932020. Diseased tissues were collected
\nfrom leaves, fruits, twigs, branches and trunks showing a range of symptoms including melanose, dieback, gummosis,
\nwood decay and canker. Based on phylogenetic comparisons of DNA sequences of the internal transcribed spacer
\nregions (ITS), calmodulin (cal), histone H3 (his3), translation elongation factor 1-alpha (tef1) and beta-tubulin (tub2),
\n393 isolates from 10 provinces were identified as belonging to 36 species of Diaporthe, including 32 known species,
\nnamely D. apiculata, D. biconispora, D. biguttulata, D. caryae, D. citri, D. citriasiana, D. compacta, D. discoidispora,
\nD. endophytica, D. eres, D. fusicola, D. fulvicolor, D. guangxiensis, D. hongkongensis, D. hubeiensis, D. limonicola,
\nD. litchii, D. novem, D. passifloricola, D. penetriteum, D. pescicola, D. pometiae, D. sackstonii, D. sennicola, D. sojae,
\nD. spinosa, D. subclavata, D. tectonae, D. tibetensis, D. unshiuensis, D. velutina and D. xishuangbanica, and four
\nnew species, namely D. gammata, D. jishouensis, D. ruiliensis and D. sexualispora. Among the 32 known species,
\n14 are reported for the first time on Citrus, and two are newly reported from China. Among the 36 species, D. citri
\nwas the dominant species as exemplified by its high frequency of isolation and virulence. Pathogenicity tests indicated that most Diaporthe species obtained in this study were weakly aggressive or non-pathogenic to the tested
\ncitrus varieties. Only D. citri produced the longest lesion lengths on citrus shoots and induced melanose on citrus
\nleaves. These results further demonstrated that a rich diversity of Diaporthe species occupy Citrus, but only a few
\nspecies are harmful and D. citri is the main pathogen for Citrus in China. The present study provides a basis from
\nwhich targeted monitoring, prevention and control measures can be developed.
Keywords:
Citrus diseases
;
Diaporthe
;
new taxa
;
pathogenicity
;
phylogenetic analysis
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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