Abstract
In 2022, 56 Phoenix canariensis palms were surveyed and sampled in Mexico City. Rot disease symptoms were observed in nine of the palms (19.412600 N, -99.195685 W). Early symptoms were brown discolouration along one or both sides of the petiole and/or rachis of the oldest (lowest) fronds (Fig. 1a). Elongated lesions extended along the petiole and rachis (Fig. 1b) leading to the lower fronds wilting and drying. The fronds remained erect and did not droop down around the trunk (Fig. 1c). Internal symptoms were a rotted and dark brown discolouration of the petiole and rachis (Fig. 2). As the disease progressed upwards, the terminal bud collapsed and the palm died. To isolate the pathogen, tissue pieces (5-mm cubes) were taken from the inner parts of the rachis and petiole, surface disinfected with 1.5% sodium hypochlorite for two minutes, rinsed three times with sterilized distilled water for one minute, plated onto potato dextrose agar (PDA) medium, and incubated at 24°C with a 12-hour photoperiod for three days. A black filamentous fungus was isolated from all nine palms with rot disease symptoms but not from the other sampled palms. Colonies on PDA were initially white with abundant fluffy aerial mycelium, which gradually turned olivaceous to black after 10 days (Fig. 3a). Pycnidial conidiomata were black and formed after 20 days (Fig. 3b). The mycelia formed chlamydospores, which were brown to dark brown (Fig. 3c-d). The conidia were thick-walled, ovoid to ellipsoid, initially hyaline and aseptate and transitioned to 1-septate with a dark brown, striated appearance (Fig. 3e), measuring 19.1-24.6 µm × 9.8-11.5 µm (mean 21.7 × 10.6, n = 100). These morphological characteristics resembled those of Neodeightonia phoenicum A.J.L. Phillips & Crous (Phillips et al., 2008). Genomic DNA was extracted from one representative isolate. The internal transcribed spacer (ITS) region, and translation elongation factor (EF-1α), and β-tubulin (TUB) genes were amplified, sequenced and deposited in GenBank (Accession Nos. ITS: PP997452.1; EF-1α: PQ621046.1; β-tubulin: PQ621047.1). A BLASTn search of the ITS sequence showed 96.95% nucleotide identity with a N. phoenicum isolate causing rot on P. canariensis in Greece (JX456475.1; Ligoxigakis et al. 2013); EF-1α had 99.67% identity with a N. phoenicum isolate causing fruit rot of coconut in Iran (PP094285.1; Habibi & Ghaderi, 2024); β-tubulin had 99.55% identity with a N. phoenicum strain causing leaf spot on P. roebelenii in China (OK338070.1; Zhang & Song, 2022). Based on the morphological and molecular data, the fungus was identified as N. phoenicum. A pathogenicity test was done twice with the representative isolate on five 5-year-old P. canariensis plants. The petioles of older fronds were surface disinfected with 75% ethanol and wounded with a sterilized scalpel. A mycelial disc of a one-week-old PDA culture of the fungus was placed on each wounded site. Five plants were inoculated with a sterile PDA plug without fungal mycelium and served as controls. All plants were maintained at 22 ±2°C with a 12-hour photoperiod. Thirty-five days after inoculation, all the inoculated fronds showed the same symptoms as those observed in the field, whereas control plants remained healthy. Fifty days after inoculation, all inoculated plants had died, and abundant pycnidia and conidia had developed on the stem and petiole (Fig. 4). The fungus was re-isolated and confirmed as N. phoenicum. To our knowledge, this is the first report of N. phoenicum causing rot disease of Phoenix canariensis in Mexico. The spread of this pathogen could have a significant ecological impact and along with other phytopathogens such as Nalanthamala vermoesenii (García-Díaz et al., 2023) and phytoplasmas (16SrIV-D subgroup) (Ortiz-García et al., 2024), previously reported in Mexico, could cause the death of a larger number of palms if timely management measures are not applied. We thank the Secretary of Education, Science, Technology and Innovation of Mexico City for financing the research project (SECTEI/212/2021): “Agents associated with the decline and death of palms in Mexico City”.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Rot symptoms occurred in nine of 56 surveyed palms in Mexico City.
- Taxon
- Phoenix canariensis
Phoenix canariensise0 - Outcome
- Rot disease symptomse0
- Value
- nine of the palmse0
- Setting
- Mexico Citye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“56 Phoenix canariensis palms were surveyed and sampled in Mexico City. Rot disease symptoms were observed in nine of the palms”
t0“Phoenix canariensis”
Claim · model-written summary
The rot produced brown petiole and rachis discoloration, elongated lesions, and wilting and drying of lower fronds.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Organ / stage
- oldest (lowest) frondse0
- Outcome
- brown discolouratione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Early symptoms were brown discolouration along one or both sides of the petiole and/or rachis of the oldest (lowest) fronds (Fig. 1a). Elongated lesions extended along the petiole and rachis (Fig. 1b) leading to the lower fronds wilting and drying.”
t0“Phoenix canariensis”
Claim · model-written summary
Disease progression caused terminal bud collapse and palm death.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Organ / stage
- terminal bude0
- Outcome
- terminal bud collapsed and the palm diede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“As the disease progressed upwards, the terminal bud collapsed and the palm died.”
t0“Phoenix canariensis”
Claim · model-written summary
A black filamentous fungus was isolated from all nine symptomatic palms but not other sampled palms.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Interactor
- A black filamentous funguse0pathogen
- Outcome
- A black filamentous fungus was isolatede0
- Value
- all nine palmse0
- Comparator
- other sampled palmse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A black filamentous fungus was isolated from all nine palms with rot disease symptoms but not from the other sampled palms.”
t0“Phoenix canariensis”
Claim · model-written summary
Morphological and molecular evidence identified the fungus as N. phoenicum.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Interactor
- N. phoenicumNeodeightonia phoenicume0pathogen
- Outcome
- identified as N. phoenicume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Based on the morphological and molecular data, the fungus was identified as N. phoenicum.”
t0“Phoenix canariensis”
Claim · model-written summary
Inoculated fronds developed field-like symptoms after 35 days whereas controls stayed healthy.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Treatment
- inoculatione0
- Outcome
- all the inoculated fronds showed the same symptomse0
- Qualifier
- Thirty-five days after inoculatione0
- Comparator
- control plantse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thirty-five days after inoculation, all the inoculated fronds showed the same symptoms as those observed in the field, whereas control plants remained healthy.”
t0“Phoenix canariensis”
Claim · model-written summary
All inoculated palms died by 50 days and developed abundant pycnidia and conidia.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Treatment
- inoculatione0
- Outcome
- all inoculated plants had diede0
- Qualifier
- Fifty days after inoculatione0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fifty days after inoculation, all inoculated plants had died, and abundant pycnidia and conidia had developed on the stem and petiole”
t0“Phoenix canariensis”
Claim · model-written summary
The fungus was re-isolated and confirmed as N. phoenicum after the pathogenicity test.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Interactor
- N. phoenicumNeodeightonia phoenicume0pathogen
- Outcome
- re-isolated and confirmed as N. phoenicume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The fungus was re-isolated and confirmed as N. phoenicum.”
t0“Phoenix canariensis”
Claim · model-written summary
The authors report N. phoenicum rot of Phoenix canariensis in Mexico for the first time.
- Taxon
- Phoenix canariensisPhoenix canariensist0
- Interactor
- Neodeightonia phoenicumNeodeightonia phoenicumt0pathogen
- Outcome
- rot diseaset0
- Setting
- Mexicot0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“First report of Neodeightonia phoenicum causing rot disease of Phoenix canariensis in Mexico”