Inheritance of Pericarp Thickness in Corn Belt Maize
1972
Helm, J. L. | Zuber, M. S.
Corn (Zea mays L.) pericarp strips were excised and thickness of the strips measured with a plunger type micrometer at six positions: upper, middle, and lower areas on the germinal and abgerminal surface. The inheritance of pericarp thickness was studied in two experiments. Experiment 1 consisted of six inbred lines ranging in pericarp thickness from 84 to 160 microns, and the 15 possible single crosses and reciprocals among them making a total of 30 F₁ hybrids. Experiment 2 was composed of six inbred lines ranging in pericarp thickness from 55 to 114 microns, their 30 F₁ hybrids, 15 F₂ progenies, 30 first and 30 second generation backcrosses. The experiments were grown at two locations in Central Missouri in 1965. Highly significant mean squares were obtained for estimates of lines, line heterosis, and specific heterosis using Gardner and Eberharts analysis II, but mean squares for lines were many fold times the mean squares for line heterosis and specific heterosis in both experiments. Reciprocal effects were of small magnitude. Heterosis was meager and inbreeding depression small. Heritability estimates in the narrow sense were very high, (80%). We conclude that breeding procedures that would take advantage of the large proportion of line effects should be successful in selection for either thin or thick pericarp
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