First Report of Neodeightonia phoenicum As the Causal Agent of Date Palm Inflorescence Rot in Iraq

Abstract

The inflorescence rot disease is considered an important disease, caused by various pathogens, including Mauginiella scaettae, Fusarium spp. and Thielaviopsis paradoxa. In this study, the fungal pathogen Neodeightonia phoenicum was isolated from different date palm fields located in Basra Province, Iraq, as the causal agent of the inflorescence rot disease. The disease symptoms included brownish to grey inflorescences, yellowing, and withering, which under severe attack causes inflorescence death. The majority of the symptoms manifested were close to the inflorescence’s apex. Molecular identification was performed using the polymerase chain reaction (PCR) technique, and the identified isolate was registered in the National Centre for Biotechnology Information (NCBI) under the name N. phoenicum BYM-6 (Accession No. LC831993.1). In healthy palm pollen, N. phoenicum’s pathogenicity test clearly revealed rot symptoms of inoculated inflorescences, indicating a high pathogenic potential for causing inflorescence rot disease. To the best of our knowledge, this work represents the first identification of N. phoenicum as the causal agent of date palm tree inflorescence rot disease (Khamedj). Results obtained showed that Trichoderma longibrachiatum is capable to restrict the growth of N. phoenicum in vitro. Thus, it can potentially be used in biological control to reduce the incidence of inflorescence rot disease on date palms, but require further investigations.

Keywords:

Inflorescence rot, Iraq, date palm, khamedj, Neodeightonia phoenicum.