THE MYCOBIOTA FROM SEEDS OF SHRUNKEN-2 (SH2) SWEET CORN

Sixteen species of fungi were isolated from the pericarp, endosperm, s cutellum, and embryo of low (<75% germination), moderate (75-89%), and high vigor (>89%) seedlots of supersweet sweet corn (sh2) hybrids ove r two years. Most frequently isolated species were Penicillium oxalicu m, Rhizopus arrhizus (14.5%), and Rhizopus spp (17.4%). Fusarium monil iforme, a common inhabitant in field or dent corn, was isolated from o nly 2.4% of the samples. The low mean isolation values may be the resu lt of poor conditions for infection or the data may reflect the method s used including sterilization techniques or random tissue selection. Aspergillus niger, F. moniliforme, and P. oxalicum, were isolated at a significantly greater level than other fungi from the high vigor hybr ids at 0.89, 0.46 m and 4.46 respectively compared to 0.04, 0, and 1.8 2 for the low vigor hybrids. When Total Fungi were compared mean isola tions were significantly greater from the high vigor hybrids at 11.96, the moderate 8.79, or low 4.86 vigor groups. When data from seed sour ces for all vigor groups were compared, significantly greater mean iso lations were obtained from Illinois Foundation Seed hybrids for Clados porium sp, R. arrhizus, and Rhizopus spp., but greater rates were obta ined for Fusarium oxysporum from the Asgrow hybrids. Isolation frequen cies for the 16 species were not significantly different between the s eed tissue types from any of the hybrids evaluated during this investi gation. Results from this study showed that there is a diverse group o f fungi present within the sh2 seed and seed treatments must be develo ped which will minimize seed rot and seedling blight from both interna l seedborne and external pathogens.