Prevalence and morphological characterization of Aspergillus isolates of maize ear rot in Punjab

Abstract

Among six fungal species viz.Aspergillus spp., Fusarium spp., Penicillum spp., Rhizopus spp., Trichoderma spp. and Alternaria spp. isolated from maize ear rot samples collected from five different districts of Punjab, the incidence of A. flavus was highest (42.15%) followed by Penicillium spp. (20.75%). The maximum frequency of A. flavus (57.10%) was found in Hoshiarpur district, closely followed by Jalandhar. In all, thirty nine isolates of Aspergillus spp. (33 isolates of A. flavus and 6 isolates of A. niger) were characterized morphologically. Twenty isolates of A. flavus producing sclerotia were of L-type strains having sclerotia diameter >400 ?m. Isolates of A. flavusproduced yellowish green, dark green and light green colonies and isolates of A. niger produced dark black colonies. Sterigmata in all the isolates of Aspergillus spp. were of uniseriate type. Based on colony diameter and growth rate per day all the 39 isolates of Aspergillus spp. were grouped into fast, medium and slow growing categories. Based on multivariate cluster analysis, the isolates of A. flavus were grouped into three distinct clusters each having 13, 17 and 3 isolates respectively.In the present study, Aspergillus flavus was found predominantly associated species with the maize ear rot. Further, the morphological variation observed within Aspergillus flavus and A. niger indicated the need for proper surveillance and monitoring exclusively for the prevention of moulds in maize produce in Punjab before it reaches the consumer.