Inheritance of isocitrate dehydrogenase, glutamate dehydrogenase and 6- phosphogluconate dehydrogenase in Zea mays (IPB var.1) and Zea mexicana (GR 021)

Date

5-1994

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Dolores A. Ramirez

Abstract

The isozyme patterns of isocitrate dehydrogenase (IDH), glutamate dehydrogenase (GDH) and 6-phosphogluconate dehydrogenase (6-PGD) found in Zeamays (IPB Var. 1), Zea mexicana (GR 021) and their Fl, F2 and BC1 hybrids were determined using polyacrylamide gel electrophoresis. The banding patterns of IDH, GDH and 6-PGD were determined and presumptive genotype/locus designations were assigned to the observed bands. For IDH, the three bands observed in the five populations were designated to two zones of activity and presumed to be controlled by two gene loci, Idhl and Idh2. Corn exhibits Idhl while both Idhl and Idh2 were present in teosinte. The presence of both loci was observed in the Fl, F2 and BC1 populations. For GDH, the four bands resolved were distributed to two zones of activity. Gdhl and Gdh2 were observed in corn and teosinte, respectively. Both loci were

observed in the succeeding generations. Lastly, the four bands of 6-PGD were designated to three zones of activity. Corn exhibited bands encoded by Pgdl and Pgd2 while Pgd3 was observed in teosinte only. All three loci were expressed in the F1, F2 and BC1 populations. Based on the 0.95/0.05 criterion, only a few gene loci encoding the three enzymes were polymorphic. Only Idhl and Gdhl of corn proved to be polymorphic. For teosinte, both Gdh2 and Pgd3 showed polymorphism. For all enzyme systems, monomorphism at the different gene loci was greatly observed. This occurrence could be attributed to the presence of the null types as the alternative alleles of that locus. No indications of heterozygosity were observed for these loci since apparent dominance is postulated to control their expression. Dominance seems to be the mode of gene action in the expression of the three enzymes. GDH and 6-PGD banding patterns have shown that more plants in the F2 resemble teosinte rather than maize. Upon backcrossing, the frequency of plants resembling corn-like genotypes increased. For all enzymes, there were bands present in the BC1 plants that were distinct to teosinte. At the biochemical level, such could indicate that genes coming from this wild relative can be 11 transferred to corn and can be conserved through generations.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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