Hybrid Corn Seed
Development and Production
Breeders produce hybrid
corn seed by cross-pollinating inbred lines. Inbred lines are produced by
self-pollinating (pollinating silks with pollen from the plant's own tassel)
selected plants with desirable characteristics. Since field corn is naturally
cross-pollinated (silks are pollinated by pollen from other plants' tassels),
special processes are used to ensure self-pollination of inbreds. Tassels
and ears are covered with a bag before silk emergence to collect pollen
and to prevent accidental cross-pollination, respectively. Pollen collected
in the tassel bag is dusted over the silk, and the tassel bag is fastened
over the ear to ensure self-pollination. Commercial hybrid production involves planting male and female inbred lines in separate rows in an isolated field where possibility of foreign pollen contamination is rare. The female inbred is normally mechanically detasselled before pollen shed to ensure cross-pollination by the male inbred. Male inbred rows are destroyed following pollination to prevent seed mixture during harvest. Ears from the cross-pollinated female inbred are harvested, processed, and sold to the producer to plant as hybrid seed.
Different crosses may be used to produce hybrid seed. Single-cross hybrids result from crossing two unrelated inbreds (A x B). Crossing the progeny of a single cross with an unrelated inbred results in a three-way cross hybrid [(A x B) x C]. Crossing the progeny of two unrelated single crosses results in a double-cross hybrid [(A x B) x (C x D)]. The vast majority of commercial hybrids are single-cross hybrids. Single-cross hybrids generally have higher grain yield and less variability in appearance and maturity than do the three-way and double crosses because they are genetically uniform.
For a graphic representation of the types of hybrids, contact your county Extension office and ask for a copy of Information Sheet 1549, Hybrid Corn Seed Development and Production.
By Dr. Erick J. Larson, Extension Agronomist
Mississippi State University does not discriminate on the basis of race, color, religion, national origin, sex, age, disability, or veteran status.
Information Sheet
1549
Extension Service of Mississippi State University, cooperating with U.S.
Department of Agriculture. Published in furtherance of Acts of Congress,
May 8 and June 30, 1914. RONALD A. BROWN, Director
Copyright by Mississippi State University. All rights reserved.
This document may be copied and distributed for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.
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Last Modified: Wednesday, 11-Feb-09 14:06:17
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