Fungal infection and mycotoxin contamination in mustard oilseeds during storage in India

摘要

To assess the quality of mustard seed during storage, an extensive survey was carried out in four mustard growing states of northern India i.e. Rajasthan, Haryana, Uttar Pradesh and Punjab. Mycoflora, surface characters and ultrastructure of freshly harvested and one year old stored seeds were investigated. Fungus induced damage in the seed coat was studied by scanning electron microscopy. Freshly harvested seeds were spherical and brown with reticulations on the surface. Growth of fungi on poorly stored seed leads to degradation of protective cuticular covering, exposing the small pores in seed coat. One year old stored seeds were often found to be heavily infected with diverse fungi. These seeds appeared to be unhealthy and discoloured due to fungal infection. Cells of the seed coat were shriveled and distorted. Transmission electron microscopy revealed degradation of oil and protein bodies in cotyledonary cells. Cytoplasm of the cells of fresh, mature seeds was packed with protein and lipid bodies,which constitute the nutrient reserves. Seed-borne mycoflora was isolated by plating the seed on Czapek's Dox agar medium.Thirty five fungal species were isolated from the seeds.