Microspectrophotometric Determination of DNA Quantities and Polypliody in Fraxinus america L.

Abstract

Quantitative determination of DNA amounts per cell for 66 Fraxinus americana trees, from 22 locations, was accomplished by Feulgen microspectrophotometric methods. Measurements of arbitrary photometric units of relative absorbance of the DNA-Feulgen dye complex were adjusted to estimates of actual DNA amounts by the use of chicken erythrocyte nuclei. A direct correlation was found between observed DNA amounts and diploid, tetraploid and hexaploid levels. A deviation of observed ploidy DNA values from a direct multiplication factor suggests that aneuploidy may be operating in the population adaptation processes. South of 40° north latitude both diploid and polyploid individuals were represented while north of 40° north latitude only diploid individuals were found.