Study of seed-borne microflora of previously stored Sorghum vulgare seeds in Rajasthan, India
An experiment was conducted at Rajasthan to determine the type of seed borne fungal pathogens associated with farmer-saved sorghum seeds. The sorghum seeds were obtained from sorghum farmers in five districts (Ajmer, Alwar, Jaipur, Jodhpur and Nagaur) of Rajasthan State. Isolation and identification of stored seed microflora by using blotter and agar plate method. Seven fungal species associated with five genera and two bacterial genera were isolated from the seed samples. Higher percent incidence of fungi was of Aspergillus niger followed by A. flavus, Curvularia lunata, A. fumigatus, Penicillium chrysogenum, Fusarium oxysporum, Helminthosporium pennisetii and bacteria E. coli, Pseudomonas aeruginosa. The most frequently isolated fungal species from seed samples each from blotter as well as agar plate method were Aspergillus niger followed by A. flavus, A. fumigatus, Curvularia lunata, Penicillium chrysogenum, Helminthosporium pennisetii and Fusarium oxysporum. It is clear from the survey that the yields of Sorghum vulgare are declining in the arid and semi-arid regions of the state. This is because, the naturally occurring seeds are not healthy (with reduced viability) and generally either infected with disease causing pathogen or such microflora which damage the seeds resulting into biodeterioration under storage conditions.