Morphological and pathogenic variabilities among Aspergillus niger isolates associated with Groundnut (Arachis hypogaea L.)

Aspergillus niger is a serious pathogen of many crops and four Aspergillus niger samples were analyzed for morphological and pathogenic nature on groundnut crop. Results revealed the predominance of Aspergillus as four isolates of Aspergillus niger viz. isolates AN-01, AN-02, AN-03 and AN-04. Significant differences were detected among four isolates in their pre and post mortality. Two isolates were rated as highly pathogenic, one as slow pathogenic, and the rest as medium pathogenic. Two fungal isolates appeared to be least virulent, whereas two isolates of diverse origin proved to be virulent on groundnut crop. These morphological and pathogenic variations in various isolates of A. niger were considered important in disease management systems and may be useful in breeding programmes of groundnut cultivars resistant to collar rot.