Vol. 4, Issue 3 (2019)
Molecular diagnosis of different isolates of Aspergillus niger isolated from grapes
Author(s): Haider A Al-Issawi, Sabah L Alwan, Aqeel N AL-Abedy
Abstract: This study was carried out in the Plant Virology laboratory of the Plant Protection Department at the College of Agriculture, University of Karbala, Iraq in order to isolate and diagnose ten isolates of Aspergillus niger isolated from stems, branches, leaves, and small grape clusters showing symptoms of black mold disease. These fungal isolates were identified using the polymerase chain reaction (PCR) technique and determining the nucleotide sequences of the amplified-PCR products using the primer pair ITS1 and ITS4. PCR amplification of DNA extracted from these A. niger isolates showed the possibility of amplifying DNA products with sizes ranging between 600bp and 700bp. Analysis of the nucleotide sequences of the PCR products amplified from A. niger isolates using the Basic Local Alignment Search Tool (BLAST) showed that all fungal isolates identified in this study belong to the fungus A. niger. A phylogenetic tree constructed using nucleotide sequences of the ten A. niger isolates was composed of three main clades. Among the A. niger isolates, the isolate (2) appeared in a separated clade with similarity percentage of nucleotide sequence ranged between 87-91% with other A. niger isolates. It was also demonstrated that the A. niger isolate (3) appeared in a separated clade along with the isolates 6 and 8 with nucleotide sequence similarity reached 99 %.