Diversity among Lasiodiplodia Species Causing Dieback, Root Rot and Leaf Spot on Fruit Trees in Egypt, and a Description of Lasiodiplodia newvalleyensis sp. nov.

Abstract

Lasiodiplodia (family Botryosphaeriaceae) is a widely distributed fungal genus that causes a variety of diseases in tropical and subtropical regions. During 2020–2021, a routine survey of fruit tree plants was conducted in five Egyptian Governorates, and fresh samples exhibiting dieback, decline, leaf spot and root rot symptoms were collected. Collection from eight different symptomatic leaves, twigs, branches and roots of fruit trees yielded 18 Lasiodiplodia-like isolates. The sequencing data from the internal transcribed spacer region (ITS), partial translation elongation factor 1-alpha (tef1-a) and β-tubulin (tub2) were used to infer phylogenetic relationships with known Lasiodiplodia species. Two isolates obtained from black necrotic lesions on Phoenix dactylifera leaves were identified as a putative novel species, L. newvalleyensis sp. nov., and were thus subjected to further morphological characterization. The results of isolation and molecular characterization revealed that L. theobromae (n = 9) was the most common species on Mangifera indica, Citrus reticulata, C. sinensis, Ficus carica, Prunus persica, Prunus armeniaca and Pyrus communis trees. Lasiodiplodia pseudotheobromae (n = 5) was isolated from M. indica, Prunus persica and C. sinensis. Lasiodiplodia laeliocattleyae (n = 2) was isolated from C. reticulata. Pathogenicity test results suggested that all Lasiodiplodia species were pathogenic to their hosts. The present study is considered the first to characterize and decipher the diversity of Lasiodiplodia species associated with fruit trees in Egypt, using the multi-locus ITS, tef1-a and tub2 sequence data, along with morphological and pathogenic trials. To our knowledge, this is the first report of L. newvalleyensis on Phoenix dactylifera and L. laeliocattleya on C. reticulata in Egypt and worldwide.

Identification and Characterization of Fungal Pathogens Contributing to Citrus Twig Dieback in Kerman Province, Iran

“…An Egyptian study identified Lasidiplodia spp. as a causative agent of citrus mortality (El-Ganainy et al, 2022). These studies show that citrus dieback is a multifactorial disease that requires further investigation and management.…”

Lasiodiplodiaspecies associated with mango (Mangifera indicaL.) decline in Burkina Faso and influence of climatic factors on the disease distribution

“…For example, eight distinct Lasiodiplodia species were identified on table grape dieback in Brazil [28]. Four species of Lasiodiplodia were associated with M indica, Citrus reticulata, C. sinensis, Ficus carica, Prunus persica, Prunus armeniaca and Pyrus communis trees dieback [29]. Taking adavantge of new sequencing methods could be useful for accurately detecting and analyzing the microbiota associated to diseased orchards.…”

Identification of Secondary Metabolites from the Mangrove-Endophyte Lasiodiplodia iranensis F0619 by UPLC-ESI-MS/MS

“…Historically, studies on Lasiodiplodia have focused on pathogenic species, likely due to the agroeconomic impact of the fungus. Additionally, the high morphological variability among species makes it difficult to reliably distinguish differences between Lasiodiplodia species [ 39 , 46 ]. Macro and micromorphology identification were performed to support the phylogenetic reconstruction.…”