| Abstract
| - Utilization of the major corn (Zea mays) reserve materials (free saccharides, starch, triglycerides,and zein) was monitored during infection of detached kernels by Aspergillus flavus (A. flavus) overa 12-day period. Inoculated whole kernels were compared to noninoculated kernels. Concentrationsof sucrose and raffinose in inoculated seed decreased to nearly zero at 6 days, whereas concentrationsof these saccharides in noninoculated seed dropped at a considerably slower rate, and significantlevels remained at the end of the incubation period. Triglyceride concentrations remained unchangedin the noninoculated seed but dropped continuously after 2 days in the inoculated seed. Starch andzein concentrations did not change during the 12-day incubation period. Aflatoxin B1 was first detectedafter 2 days and increased to about 20 μg/g (20,000 ppb) after 12 days. Very low aflatoxinconcentrations were detected in the noninoculated seed. Significant concentrations of erythritol,arabitol, and mannitol were produced during infection, with peak concentrations occurring at 8 days.Whole seed and germ tissue appeared to support good fungal growth and aflatoxin production,whereas ground tissues and endosperm did not. A. flavus preferentially utilized saccharides as initialcarbon substrates followed by triglycerides. When invading nonwounded corn kernels, the fungusselectively targets the germ tissue where these materials are localized in the highest concentrations. Keywords: Aflatoxin; Aspergillus flavus; cornstarch; raffinose; sucrose; sugar alcohols; triglycerides;Zea mays; zein
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