Alternaria phoenicis sp. nov. and Alternaria ouedrighensis sp. nov. (Pleosporales, Pleosporaceae): Two new species associated with leaf spot and blight diseases of date palm (Phoenix dactylifera L.)

Abstract

Date palm (Phoenix dactylifera L.) is one of the oldest fruit crops grown in the semi-arid and arid regions, playing significant ecological, environmental and socio-economic roles. Recently, palm leaf spot and blight diseases have indeed emerged as significant threats to phoeniciculture. They reduce yield and quality of dates leading to economic losses.

Therefore, a survey was conducted in four palm groves located in the Biskra and Ghardaia provinces of Algeria. This investigation revealed two new Alternaria species associated with leaf spot and blight symptoms on date palm. These newly identified species are designated as A. phoenicis sp. nov. and A. ouedrighensis sp. nov., which belong to the Ulocladioides and Embellisia sections, respectively.

The isolates were phylogenetically identified using the key genetic markers of the genus including the large subunit ribosomal DNA (LSU), internal transcribed spacer region of the ribosomal RNA (ITS), glyceraldehyde- 3 - phosphate dehydrogenase (GAPDH), RNA polymerase II subunit (RPB 2), translation elongation factor (TEF 1) and plasma membrane (ATPase) genes and illustrated based on the morphological characteristics.