Relatedness Among Plants as Measured by the DNA-Agar Technique

Abstract

An improved method for extraction of plant DNA is described. Quantitative species comparisons based on DNA-DNA hybridization are reported for several members of the family Leguminosae and for barley, wheat and rye. A maximum of about 10% homology in DNA polynucleotide sequences is found between monocotyledons and dicotyledons tested, whereas 20 to 90% homology is observed within a family. Species compared using a DNA fraction enriched for redundant polynucleotide sequences generally appear to be more closely related than when whole DNA is used. DNA-DNA hybridization may be useful in systematic and evolutionary study of plants, and also as a possible screening procedure for interfertility of species.