Phylogeny and pathogenicity of Lasiodiplodia species associated with dieback of mango in Peru

Area of Science:

• Plant Pathology
• Mycology
• Tropical Agriculture

Background:

• Mango (Mangifera indica L.) is a vital tropical fruit crop in Piura, Peru.
• Dieback disease, caused by Lasiodiplodia species, poses a significant threat to mango production in the region.
• Previous research has not fully characterized the Lasiodiplodia species associated with mango dieback in Piura.

Purpose of the Study:

• To determine the incidence and prevalence of mango dieback in Piura, Peru.
• To identify the Lasiodiplodia species causing mango dieback using morphological and molecular methods.
• To evaluate the pathogenicity of identified Lasiodiplodia species on mango plants.

Main Methods:

• Field surveys were conducted across mango orchards in Piura to assess dieback incidence and prevalence.
• Fungal isolates were identified based on morphological characteristics, cultural traits, and DNA sequencing of the rDNA internal transcribed spacer (ITS) region and translation elongation factor 1-alpha (tef1-α) gene.
• Pathogenicity tests were performed on mango plants to confirm disease causation and assess isolate aggressiveness.

Main Results:

• Mango dieback was found in all surveyed orchards, with varying incidence across locations.
• Six Lasiodiplodia species were identified: L. brasiliense, L. egyptiacae (L. laeliocattleyae), L. iraniensis, L. pseudotheobromae, L. theobromae, and a potential hybrid Lasiodiplodia sp.
• L. theobromae was the most prevalent species; L. brasiliense, L. egyptiacae, L. iraniensis, L. pseudotheobromae, and the Lasiodiplodia sp. are newly reported from Peru, with L. iraniensis being a novel pathogen of mango.
• Pathogenicity trials confirmed the role of these species in mango dieback and demonstrated varying levels of aggressiveness.

Conclusions:

• This study provides the first comprehensive report on Lasiodiplodia species associated with mango dieback in Piura, Peru.
• The identification of multiple Lasiodiplodia species, including novel reports for Peru and mango, highlights the complex etiology of the disease.
• Understanding the diversity and pathogenicity of these fungi is crucial for developing effective disease management strategies to protect mango production in the region.