Caterpillar-Repelling Corn Now Available
By Jan Suszkiw
May 9, 2002
Agricultural Research Service scientists
are accepting requests for seed of two dent corn populations that produce
plants whose silks contain maysin, a natural repellent against hungry
Crossing the maysin-rich corn with elite commercial lines should enable
plant breeders to eventually provide farmers with hybrids that withstand attack
by corn earworms, according to Neil Widstrom, a geneticist at ARS
Crop Genetics and Breeding
Research Unit in Tifton, Ga.
Farmers main defense against the caterpillar pest in sweet corn is to
spray the crop with insecticides, sometimes as often as 30-40 times a season.
But a crop of maysin-rich corn could cut farmers insecticide use by about
half, scientists predict.
Maysin works by binding up certain proteins in the earworms gut so
that it cannot grow. Humans, other animals and beneficial insects face no such
danger, according to Widstrom. He and colleagues used conventional plant
breeding and back-crossing techniques to produce the high-maysin corn. First,
they selected plants whose silks produce enough maysin to stop earworms from
feeding after just a few bites. Second, they also chose plants with tight husks
so the pest is forced to chew the silks before the kernels, which dont
contain maysin. The researchers also showed its possible to transfer the
high-maysin trait from dent corn to sweet corn.
Registration of EPM6 (a high-maysin, purple-kerneled dent corn) and SIM6 (a
yellow- kerneled dent corn) in the November-December issue of the journal Crop Science marks 23 years of
maysin research by scientists at ARS labs in Berkeley, Calif.; Columbia, Mo.;
and Tifton in cooperation with the University of
Georgia, notes Widstrom.
ARS Tifton lab will honor requests for breeder seed for five years,
adds Widstrom. Samples are limited to 300-500 seeds per request. A longer story
about the maysin corn appears in the
issue of Agricultural Research.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.