Inheritance of a Mutation for Dwarfness in Soybeans1
- W. R. Fehr2
Dwarf soybean plants [Glycine max (L.) Merr.] were found in a row of the ‘Hark’ variety at Ames, Iowa in 1966. All plants in the row were from seeds of a single plant harvested from a foundation seed field of Hark the previous year. The plants had short internodes and petioles. The leaves were similar in shape to normal Hark, but were only one-fourth normal size. The flowers were approximately three-fourths the size of normal Hark, but were not abnormally eleistogamous. The inheritance of the Hark dwarf and its relationship to the ‘Lincoln’ dwarf (df2) and the ‘Adams’ dwarf (df3) genes were studied.
The crosses of Hark normal ✕ Hark dwarf, Lincoln dwarf ✕ Hark dwarf, and Adams dwarf ✕ Hark dwarf were studied in F1; F2, and F3. The Hark dwarf was controlled by a single recessive allele, designated df4, that was nonallelic to df2 and df3 and independently inherited. No distinct double recessive phenotype was observed. There was a satisfactory fit to a ratio of 9 normal:3 Hark dwarf:4 Lincoln dwarf in the Lincoln dwarf ✕ Hark dwarf cross and a 9 normal:3 Hark dwarf:4 Adams dwarf in the Adams dwarf ✕ Hark dwarf cross. These data indicated that df2df2df4df4 F2 plants were classified phenotypically as Lincoln dwarfs, and the df3df3df4df4 F2 plants, as Adams dwarfs.
There was a range in height for F2 and F3 individuals of all three dwarf: types, indicating that expression of the df2 df3, and df4 alleles may be influenced by modifying genes.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .