<figure><img src="image_1.png" /></figure>

# First report of *Lasiodiplodia brasiliense* causing mango dieback in Côte d'Ivoire

Y. S. Yéo<fnref n="1" />,<fnref n="2" /> | D. D. Dembélé<fnref n="3" /> | B. Camara<fnref n="1" />,<fnref n="2" /> | E. G. L. D. Amari<fnref n="1" />,<fnref n="2" /> | J.-Y. Rey<fnref n="4" />
D. Koné<fnref n="1" />,<fnref n="2" /> | D. Fernandez<fnref n="5" />

**Correspondence**

Y. S Yéo, UPR of Plant Physiology and Pathology, University Félix Houphouët-Boigny, UFR Biosciences, 22 BP 582 Abidjan 22, Côte d'Ivoire. Email: souleymaneyeo2@gmail.com

**Funding information**

Partnership for Skills in Applied Sciences, Engineering, and Technology - Regional Scholarship and Innovation Fund, Grant/Award Number: (PASET-RSIF)

**KEYWORDS**

Botryosphaeriaceae, *Mangifera indica*, mango decline, fungal disease

In 2020, surveys of mango (*Mangifera indica*) orchards across the departments of Boundiali (9°36′34.668″N, 6°41′16.1628″W), Korhogo (9°17′11.1228″N, 5°37′6.8016″W) and Odienné

(9°31′16.3992″N, 7°36′15.93″W) revealed the presence of mango dieback symptoms, such as leaf, twig and branch drying from the top of the tree downwards as well as death of the whole tree (Fig. 1). The disease incidence varied from 20 to 100%.

<figure><img src="image_2.png" /><figcaption>**FIGURE 1** Mango dieback symptoms observed in field: (a) leaf curling and drying; (b) dieback of young twig from the tip; (c) mango tree with dried out branches.</figcaption></figure>

<figure><img src="image_3.png" /><figcaption>**FIGURE 2** Morphological features of fungal colony isolated from a tree with mango dieback (isolate YANRSYA5): (a) front and (b) reverse.</figcaption></figure>

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

© 2024 The Author(s). *New Disease Reports* published by John Wiley & Sons Ltd on behalf of British Society for Plant Pathology.

<footnote n="1">¹UPR of Plant Physiology and Pathology, University Félix Houphouët-Boigny, UFR Biosciences, Abidjan, Côte d'Ivoire</footnote>

<footnote n="2">²Wascal / African Center of Excellence in Climate Change, Biodiversity and Sustainable Agriculture (CEA-CCBAD), University Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire</footnote>

<footnote n="3">³UFR Sciences Biologiques, Département de Biologie Végétale, Université Péléforo Gon Coulibaly (UPCG), Korhogo, Côte d'Ivoire</footnote>

<footnote n="4">⁴HortSys, Université Montpellier, CIRAD, Montpellier, France</footnote>

<footnote n="5">⁵UMR PHIM, Université Montpellier, IRD, CIRAD, INRAE, Institute Agro, Montpellier, France</footnote>
<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /><figcaption>**FIGURE 3** Morphological features of isolate YANRSYA5: (a) conidiomata formed on pine needles on water agar; (b) conidiogenous layer with conidiogenous cells and paraphyses; (c) hyaline immature conidia; (d-e) mature, brown and dark conidia in two different focal planes. Bars: b = 50 µm, c-e = 20 µm.</figcaption></figure>

<figure><img src="image_6.png" /><figcaption>**FIGURE 4** Maximum likelihood tree of *Lasiodiplodia brasiliense* (isolate YANRSYA5) based on ITS and *tef1-α* sequences dataset using Kimura 2-parameter model with 1,000 bootstrap replications. Strain accession numbers follow the species name, and the isolate from the current report is in red. The bootstrap support values >50% are given at the node. There were a total of 278 positions in the final dataset. *Diplodia mutila* (CMW7060) is used as the outgroup taxon. Evolutionary analyses were conducted in MEGA (Tamura et al. 2021).</figcaption></figure>

Isolation was performed on samples of diseased organs (leaf, twig, branch and trunk) on potato dextrose agar (PDA) medium and plates were incubated at 25°C in darkness for one week. A representative isolate YANRSYA5 was selected and transferred onto 2% water agar (WA) containing sterilised *Pinus nigra* needles. Plates were incubated at 25°C with an eight-hour photoperiod for four weeks to induce the formation of fruiting bodies and sporulation. Colonies produced dense aerial mycelium, initially white, which turned to dark brown and black (Fig. 2). At this stage, dark coloured pycnidia were formed (Fig. 3a).

Conidiogenous cells were hyaline, thin-walled or smooth. Conidia were subovoid to ellipsoidovoid, with the apex broadly rounded, thick-walled, and contents granular. Initially the conidia were hyaline and aseptate, then dark brown and one-septate with longitudinal striations (Fig. 3b-e). Conidia were 16.23-30.53 × 11.45-16.51 µm (mean ±S.D = 24.08 ±3.25 × 13.55 ±1.2 µm, L/W ratio = 1.77; n = 50). The cultural and morphological characteristics of the isolate were similar to those reported for the genus *Lasiodiplodia* (Phillips et al., 2013).
<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /><figcaption>**FIGURE 5** Pathogenicity of *Lasiodiplodia brasiliense* (isolate YANRSYA5) on mango plants 60 days after inoculation in a greenhouse: (a) control plants without symptoms, (b) leaves withered and desiccating, (c) brown to black discolouration and necrosis of vascular system (arrows show the inoculation site).</figcaption></figure>

Genomic DNA was extracted and the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) and translation elongation factor (tef1-α) were amplified by PCR and sequenced with ITS1/ITS4 and EF1-688F/1251R primers, respectively. A BLASTn search revealed 100 % identity with GenBank Accession Nos. JX464063.1 (ITS) and JX464049 (tef1-α) in GenBank corresponding to *Lasiodiplodia brasiliense* (Fig. 4). The ITS and tef1-α sequences of isolate YANRSYA5 were deposited in GenBank (OQ067216 and OQ269653 for ITS and tef-1α, respectively).

A pathogenicity test was performed according to Ismail et al. (2013). Plants were maintained subsequently in a greenhouse at 30 to 35°C for 60 days. The leaves of inoculated plants became withered and desiccated, whereas the control plants remained asymptomatic (Fig. 5). *Lasiodiplodia brasiliense* was re-isolated from all the inoculated plants, fulfilling Koch's postulates.

*Lasiodiplodia brasiliense* has been reported in several major mango-production regions, such as Mexico (Bautista-Cruz et al., 2019) and Peru (Rodríguez-Gálvez et al., 2017) causing canker and dieback symptoms. This study represents the first report of mango dieback disease caused by *Lasiodiplodia brasiliense* in Côte d'Ivoire. Further studies should be undertaken to assess variation among the isolates and

whether other species of *Lasiodiplodia* are associated with the disease in order to elaborate control strategies.

## ACKNOWLEDGMENT

This research was funded by Partnership for Skills in Applied Sciences, Engineering, and Technology - Regional Scholarship and Innovation Fund (PASET-RSIF). The authors acknowledge the support of the Fondation Louis Omer DECUGIS and the Société Internationale d'Importation (SIIM, France)

## ORCID

Y.S. Yéo https://orcid.org/0000-0001-8471-2897

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**How to cite this article:** Yéo, Y.S., Dembélé, D.D., Camara, B., Amari, E.G.L.D., Rey, J.-Y., Koné, D. et al. (2024) First report of *Lasiodiplodia brasiliense* causing mango dieback in Côte d'Ivoire. *New Disease Reports*, 50, e12299. https://doi.org/10.1002/ndr2.12299