Genetic Diversity Using Random Amplified Polymorphic DNA (RAPD)Analysis for Aspergillus niger isolates

Abstract

This study includes isolation, purification, and identification of Aspergillus niger
from different sources (soil, Seeds, powdered milk and factory waste water) by
traditional methods (macroscopic and microscopically). and study the relationships
of genetic among the A. niger isolates based PCR (RAPD) technique (find the DNA
fingerprint). The results of this study revealed that genetic diversity and
relationships among twenty four isolates were determined by using the random
amplified polymorphic DNA (RAPD) technique. Genomic DNA of each isolates
was extract at final concentration of (115-959) μg /l per (2-3) gm of wet mycelium,
and at a purity (1.7-1.9). Each DNA of isolates were amplified with each 24 primers
and the products were resolved electrophoretically on 1.2% agarose gel, stained with
ethidium bromide and photographed under UV light. Ten primers failed to amplify
DNA of A. niger isolates but the rest 14 primers produced 367 bands, of these bands
99.4% (365) bands were polymorphic. The size of the amplified bands ranged
between 130-2840 bp. The genetic polymorphism value of each primer was
determined and ranged between 86-100%. All primer have given unique bands. The
primers were fingerprinted 21 of the 24 isolates. Genetic distances ranged from
0.11496 to 0.68088 between A. niger isolates. Also, cluster analysis of genetic
distances between these isolates have divided into groups according to the source,
which isolated them and this indicates the presence of a high level of genetic kinship
samples isolated from the same source at the same time which indicates the
presence of a high level of genetic distance between samples isolated from different
sources.