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Evaluation of performance of corn yield trails in a commercial corn breeding program in the United States corn belt: Measurement of genetic gain
Abstract
The evaluation of the genetic gain or response from selection in the different stages of hybrid development is a very important practice in a yield trial program. This practice allows plant breeders to measure and adjust breeding programs on the basis of their performance. The objectives of this research were to compare the magnitudes and differences of genetic parameters in hybrids at early, intermediate, and advanced stages of hybrid development. In addition to selection differential, predicted and genetic gain for grain yield and moisture were compared as well as differences in genetic gain between the two corn (Zea mays L.) heterotic groups, Stiff Stalk (SS) and Non-Stiff Stalk (NSS), of the US Cornbelt. This evaluation was conducted in a corn yield trial program of a commercial company with most locations being in Nebraska. Results indicate that SS hybrids at early stage showed as much as seven times bigger genetic variance for grain yield than the NSS hybrids. The mean grain yield for the SS hybrids was 0.51 t ha−1 higher than the one for the NSS hybrids. At the intermediate stage, hybrids showed components of variance for genetic, location, genotype by location interaction, and error very similar for both heterotic groups. SS hybrids yielded 1.85 t ha−1 more than the NSS hybrids. At the advanced stage SS hybrids yielded 1.16 t ha−1 more than the NSS hybrids. The genetic gains for, grain yield of selected hybrids in Phase I (early to intermediate stages) and Phase II (intermediate to advanced) were 0.09 and −0.26 t ha−1 respectively. At Phase I, a significant linear relationship at the 90% probability level was found using pooled data of both heterotic groups for the relationship between genetic gain and genetic variance for grain yield. At Phase II, genetic gain regressed on grain yield of selected hybrids in combined data of both heterotic groups gives a positive and significant relationship between these two variables.
Subject Area
Agronomy|Genetics|Plant propagation
Recommended Citation
Saldivar-Davila, Jesus Demetrio, "Evaluation of performance of corn yield trails in a commercial corn breeding program in the United States corn belt: Measurement of genetic gain" (1998). ETD collection for University of Nebraska-Lincoln. AAI9917857.
https://digitalcommons.unl.edu/dissertations/AAI9917857