Genetic type T218M was found in 'Illini' in 1952 at Urbana, IL. T218H was derived from T218M by crossing a yellow branch as male parent with Illini. The F1 plants were green. Segregation in the F2 gave 3 green: 1 yellow lethal plants. F2 green plants gave ratios of 1 nonsegregating: 2 segregating prog-enies in the F3 generation, confirming monogenic inheritance (Palmer, 1978, unpublished). The recessive allele is carried as the heterozygote in T218H.
Hatfield, Peggy M. and Palmer, Reid G.
"Research Notes : United States : Allelism tests of T218H and T225H,"
Soybean Genetics Newsletter: Vol. 13
, Article 35.
Available at: https://lib.dr.iastate.edu/soybeangenetics/vol13/iss1/35