First Report of Cockscomb Root Rot Caused by Fusarium solani in Iraq

Abstract

Cockscomb ( Celosia argentea L.) is one of the most important ornamental plants in Iraq. In August 2021, severe root rot of cockscomb plants was observed, with an incidence of 30%, in all of the nurseries surveyed in the Karbala and Babylon provinces, Iraq. The symptoms appeared as severe leaf chlorosis and wilting with brown discoloration of the stem vascular bundle associated with dark brown lesions on the root that extended to the root collar and became extensive rot. The morphological features of 50% of the fungal colonies were identical and similar to those of Fusarium spp. The internal transcribed spacer, translation elongation factor, RNA polymerase I and II, beta-tubulin 1, and mitochondrial small-subunit ribosomal RNA genes were amplified and sequenced. BLASTn analysis of these genetic markers’ sequences found 99.84 to 100% similarity with the corresponding global sequences of Fusarium solani (Mart.). This identification was confirmed by phylogenetic analysis of the concatenated sequences of the genetic markers. Although F. solani has caused economic damage to a broad range of commercially important plants in Iraq, to our knowledge, this is the first report of F. solani causing root rot of cockscomb ( C. argentea) in Iraq.