DNA CONTENT, RIBOSOMAL-RNA GENE NUMBER, AND PROTEIN CONTENT IN SOYBEANS

Abstract

Six cultivars and five plant introductions of Glycine max L. Merr. varied in picograms of DNA per cell from 1.84 to 2.61, and in number of ribosomal-RNA genes per 2 C nucleus from 960 to 2431 (Laboratory 1, Ames) and from 768 to 2095 (Laboratory 2, Rhinelander). The parameters did not correlate with seed protein content, which varied from 32.8% to 52.6%. With these materials, use of the rRNA locus size as a breeding tool for increasing percentage protein content by use of cytogenetic and genetic manipulations is not warranted.