Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 29, 1996
Publication Date: N/A
Technical Abstract: This research contrasts the aflatoxin and ergosterol levels of BGYF kernels from different corn varieties as a strategy for identifying potential sources of chemical and biochemical resistance to Aspergillus flavus infection and aflatoxin contamination of the germ or endosperm region. Individual BGYF kernels offer proof that A. flavus gained entry to the seed proper, infected the germ, and produced kojic acid. Corn varieties susceptible to 'seed coat tearing' thus provide a meaningful way to learn if the seed proper (germ and endosperm) shows any resistance to A. flavus infection and aflatoxin contamination of preharvest corn. Commercial corn hybrids and inbreds showing numerous undamaged BGYF kernels were identified in aflatoxin resistance trials conducted at Mt. Vernon, IN (1995). BGYF kernels were removed from each grain sample (harvested row), milled, and analyzed for aflatoxin (ppb) and ergosterol (ppm). There was substantial variation in the amount of aflatoxin accumulation in BGYF kernels from hybrids (e.g. 90-4800 ppb) and inbreds (e.g. 12-1294 ppb). Likewise, estimated actual ergosterol values showed substantial variation among corn varieties (hybrids = 1.3-21 ppm; inbreds = 1.4-281 ppm). This is further evidence that corn varieties differ in their internal resistance to pre-harvest A. flavus infection and aflatoxin contamination. Our goal is to produce hybrids that combine resistance to seed coat tearing with germ and endosperm resistance to A. flavus infection and aflatoxin biosynthesis.