Data from: Combining ability of experimental maize lines for yield and aflatoxin in the southeastern USA

Aflatoxin contamination of maize (Zea mays L.) grain presents risks to
animal and human health and causes economic losses for growers,
particularly in the southeastern United States. Development of hybrids
with genetic resistance to aflatoxin contamination by Aspergillus
flavus will reduce these risks. Two factorial crossing experiments were
conducted to evaluate yield, agronomic traits, and aflatoxin in maize
hybrids. In Exp. 1, 18 aflatoxin-resistant (GT) lines were each crossed to
six testers. In Exp. 2, 13 of the same lines were each crossed to 10
different testers. Each experiment was conducted for two years at Tifton,
GA and commercial check hybrids were included for comparison. 
Ears were inoculated with A. flavus isolate NRRL 3357 using the
side-needle technique 14 d after silking. Aflatoxin was quantified after
harvest. Broad sense heritability for aflatoxin was low in Exp. 1 (H2 =
0.09) but was higher in Exp. 2 (H2 = 0.27). Heritability was moderate to
high for plant height (H2 = 0.49–0.51) and days to silking (H2 =
0.54–0.72).  Among experimental lines, GT1209 and GT1309 had
consistent positive general combining ability (GCA) for yield, whereas
GT1203 and GT1204 had consistent negative (favorable) GCA for aflatoxin.
Significant GCA effects, both positive and negative, for aflatoxin were
also observed among testers in both experiments. Some experimental hybrids
had yields that were comparable to commercial checks while also having
lower aflatoxin, demonstrating the progress made in improvement of both
traits in maize hybrids adapted to the Southern United States.