Molecular Identification of Fungal Pathogens of Date Palm Root Rot in Egypt

Abstract

In tropical and subtropical regions, date palm is a highly significant fruit tree, known for its more than 3,000 different varieties found around the world. However, in Egypt, date palms are susceptible to infection by root rot disease (RRD) caused by various harmful soil borne fungi. This leads to significant damage to both trees and their offshoots. The most harmful fungi found in Egypt included: Fusarium oxysporum, which causes deterioration of palm roots, as well as F. moniliforme, F. solani, Thielaviopsis paradoxa, Botryodiplodia theobromae and Rhizoctonia solani. A survey and collection of date palm samples was carried out in five districts (Kharga, Baris, Balat, Dakhla and Frafra) within New Valley Governorate, Egypt were carried out. Pathogenicity tests and disease severity confirmed the presence of 15 fungal species belonging to six genera, which identified as Acrocalymma vagum, Curvularia australiensis, C. lunata, C. spicifera, Exserohilum rostratum, F. oxysporum, F. solani, Marasmius palmivorus and Talaromyces pinophilus. Through molecular identification using internal transcribed spacers (ITS), it has been determined that these eight new pathogenic fungal isolates, were not previously identified in date palms in Egypt, belong to the species: A. vagum, A. vagum, C. australiensis, C. lunata, C. spicifera, E. rostratum, M. palmivorus, T. pinophilus. This finding represents the first documented association of these eight fungi with date palm RRD in Egypt.