Record Details
Influence of chelating agents on genetic recombination of Zea mays L.
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Influence of chelating agents on genetic recombination of Zea mays L. |
| Names |
Ihrke, Charles Albert
(creator) Kronstad, Warren E. (advisor) |
| Date Issued | 1969-07-03 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Crossover frequencies for seven selected regions on five chromosomes of maize were measured to ascertain the effect of chelating agents on recombination. Ethylenediamine tetraacetic acid, EDTA, and dimethyl sulfoxide, DMSO, were used in three concentrations singly, and in all combinations. Plants heterozygous for for linked genes governing seed and seedling characteristics were treated with premeiotic foliar spray of EDTA and DMSO for two durations. Appropriate crosses were made and crossover frequencies were calculated from data resulting from test cross and sib cross progeny. The chelating agents were found to influence the frequency of recombination in each of the regions tested. Crossover reduction was found at high concentrations of the chemicals and at the longer treatment duration. It was concluded that a threshold had been reached causing interference with crossing over or with recovery of crossover products. Crossover frequencies were significantly increased in five chromosome regions by several concentrations of the chelating agents. Although the two agents have different cation affinities, both were found to influence crossing over, indicating that the action was by a mechanism other than the removal of a specific cation from the chromosome. Changes in recombination frequency were found to be of similar magnitude whether the chelating agents were used alone or in combination. It was concluded that the two chemicals did not have a synergistic effect in changing recombination frequency. A relationship was shown between length of crossover region and effect of the chemical treatment. No such relationship was found between the specific locations in chromosomes and response to chelating agents for the seven regions tested. Use of chelating agents offers the possibility of increasing genetic variability. Induction of recombination in a short chromosome region may improve a crop variety by breaking an undesirable gene combination, by linking together genes from adjacent regions of homologous chromosomes, or by producing a novel pleiotropic effect. |
| Genre | Thesis/Dissertation |
| Topic | Corn -- Genetics |
| Identifier | http://hdl.handle.net/1957/45639 |
