Use of Allozymes as Genetic Markers for Predicting Performance in Maize Single Cross Hybrids1
- O. M. Frei,
- C. W. Stuber and
- M. M. Goodman2
The possible use of allozymes in inbreds of maize (Zea mays L.) for predicting single cross performance has been proposed by many maize breeders. This potential use was evaluated in an experiment involving a large group of publicly available inbreds. The six testers, B73 and B14A (Stiff Stalk type), Mol7 and Oh43 (Lancaster type), K55 (from ‘Pride of Saline’), and T8 (from ‘Jarvis’) were chosen, each representing different germplasm sources (populations). Based on allozyme genotypes at 21 enzymeloci, a genetic relatedness measure of 406 inbreds with the six tester lines was generated and line pairs were classified into similar (SA) or dissimilar (DA) allozyme groups. A second genetic relatedness measure was based on pedigrees. Lines derived from the same population were considered to have similar pedigrees (SP); lines derived from different populations were classified as having dissimilar pedigrees (DP). Each tester was crossed to a set of lines (usually five) from each of the four allozymepedigree combinations. Different sets of lines were used for the single crosses with each of the testers. These single crosses were field tested in seven environments. Significantly higher yield (10%) was observed in the DA class than in the SA class. The DP class outyielded the SP class by 37%. In spite of the highly significant main effects of allozymes and pedigrees, allozyme dissimilarity was associated with higher yield only when the pedigree background was similar (SP-class). In hybrids of lines from different populations (DP-class) the allozymes showed no association with yield. Neither allozymes nor pedigrees were associated with yield in crosses to B73, indicating that exceptions from the general associations occur, depending on the tester.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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