Morphological and Molecular Identification and Categorization of Aspergillus Isolates Associated with Different Crops from Delhi Market, India

Abstract

Aspergillus species infecting fruits (Apple & Brinjal) and crop seeds (Maize, wheat, beans, groundnut, paddy and
black gram) collected from the market of Delhi during 2008 were identified by using morphological and molecular
methods. Sixty-five diseased specimens of fruits and crops were collected from the market and isolations of the
pathogens were made. Twenty isolates of Aspergillus were separated on the basis of genus characters. The isolates
were further categorised into five different species based on their colony characters, viz. colony growth, color and
texture and microscopic observations,i.e. conidial head, conidiophore, vesicle, sterigmata and conidia. Random
amplified polymorphic DNA (RAPD) fingerprints using six arbitrary 10 mers primers clearly separated the species.
Morphological grouping and speciation matched with the molecular grouping for most of the isolates. The random
primer OPB11 gave reproducible and very stable result for strain delineation of five examined pathogenic
Aspergillus species (A. niger, A. flavus, A. parasiticus, A. terreus and A. ochraceus) in comparison to other primers
and this primer was used to develop species specific marker to identify Aspergillus flavus as it gave monomorphic
band for all the A. flavus isolates studied.