Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Progress from ear-to-row selection in two corn (Zea mays L.) populations
Abstract
Evaluation of progress from recurrent selection by using the modified ear-to-row method in Hays Golden and Exotic Composite populations is reported in this research study conducted at Lincoln, Nebraska. Fourteen and eight cycles of selection in Hays Golden and Exotic Composite, respectively, were evaluated under irrigated and dryland environmental conditions in 1986 and 1987. This experiment was performed in order to estimate the realized gain of the above two populations. The half-sib families of C14 and C8 of Hays Golden and Exotic Composite were evaluated to measure the genetic variability within those populations. This evaluation study was conducted under the same environmental conditions mentioned above, except that the half-sib families of Exotic Composite were evaluated only under irrigated conditions. The selection criterion used in the selection study was a multiplicative selection index composed of yield (adjusted to 15.5% moisture), proportion of upright plants, and proportion of retained ears. Significant improvement for index at the rate of 1.97% per cycle was obtained for the Hays Golden population whereas a positive change (lacking significance) of 3.16% per cycle was observed for index in the Exotic Composite population. Selection for an increase in index also has resulted in increased ears per plant at the rate of 2.20% and 2.02% per cycle for Hays Golden and Exotic Composite, respectively. Expected responses/cycle in index for Hays Golden C14 and Exotic Composite C8 were calculated to be at the rate of 1.08 and 2.08% of their CO. The observed responses (1.97 and 3.16%) were larger than expected responses for both populations. So far, the ear-to-row method has been found to be an effective scheme for the improvement of both Hays Golden and Exotic Composite populations. Evidence is shown by the progress obtained as well as the maintenance of genetic variability found for most of the traits among half-sib families for both populations.
Subject Area
Agronomy
Recommended Citation
Navarro-Guerrero, Enrique, "Progress from ear-to-row selection in two corn (Zea mays L.) populations" (1988). ETD collection for University of Nebraska-Lincoln. AAI8824948.
https://digitalcommons.unl.edu/dissertations/AAI8824948