Fig. 1

Identification of the stem-end rot pathogen in citrus fruits. (A) Two fungal strains (HGC201, HGC286) resembling Colletotrichum fungi were isolated from stem-end rot orange fruits. Fungal strains were cultivated on PDA at 25 °C for 5 days for morphological analyses. (B) Molecular identification of strains HGC201 and HGC286 by ITS rDNA sequencing. The ITS sequences were compared to GenBank using the BLAST tool. The phylogenetic tree was constructed with MEGA X using the neighbor-joining method and 1000 bootstrap replications. Statistical support values at branch nodes of the tree, genetic distance scale, and accession numbers for the ITS sequences from other fungi are indicated. The ITS sequences for two C. gloeosporioides strains (HGC201 and HGC286) are deposited in GenBank with accession numbers OL739236−OL739237. (C) Reinfection of the isolated strains on citrus fruits to confirm their pathogenicity. Fungal spore suspensions (10⁶ spores/mL) were employed for the fruit infection assays. Negative control fruits (mock) were inoculated with SDW. The fruits were incubated in sterile plastic boxes for 10 days. Scale bars indicate the sizes of the images. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)