Inheritance of Tolerance to Hoe 23408 in Corn1
- J. L. Geadelmann and
- Robert N. Andersen2
We conducted experiments to determine the inheritance of tolerance in corn (Zea mays L.) to HOE 23408 (methyl-2-[4-(2,4-dichlorophenoxy) phenoxy]propanoate), an herbicide that has been effective in controlling volunteer corn in soybeans [Glycine max (L.) Merr.]. Three tolerant and three susceptible inbred lines, their 30 singlecross hybrids (Fl's) including reciprocals, and the sibbed Fl's (F2's) were grown in two adjacent experiments planted 4 weeks apart in 1975 near Rosemount, Minn. Each experiment contained three replications of pairedrow plots, and one row of each pair was sprayed over the top with 0.86 kg/ha of HOE 23408 when the corn had six to seven fully-expanded leaves. Percent control was rated 3 weeks after spraying.
Percent control did not differ significantly between experiments or among reciprocals. Genotype ✕ experiment interaction was significant but accounted for less than 5% of the variation among genotypes and experiments. Gene action for percent control was primarily additive, with 91% of the variation among F1 means accounted for by fitting only general combining ability effects. Analysis of F2 data also indicated a preponderance of additive gene action. Significant heterosis and nonadditive gene action were present, but they were not of major importance. Broad-sense heritability values (individual F2-plant basis) averaged 95.3%, and relative frequency distributions of percent control ratings on F2 plants indicated several loci controlled tolerance to HOE 23408. More than half of the F2 plants from tolerant ✕ tolerant and tolerant ✕ susceptible F1's were less than 75% controlled by HOE 23408. Therefore, satisfactory control of volunteer corn in soybeans by foliar application of HOE 23408 depends in part on the pedigree of corn hybrids grown the previous year.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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