A Genetical Puzzle
Acta botanica neerlandica , Volume 4 - Issue 3 p. 471- 473
Two pairs of characters of maize endosperm find an extensive use for demonstrational purposes: blue versus yellow and smooth versus wrinkled. For the blue colour four independent and complementary genes are responsible: A, (Emerson (1918) chromosome 3), A2 (Jenkins (1932) chromosome 5), C (East and Hayes (1911) chromosome 9) and R (East and Hayes (1911) chromosome 10). For smooth (starchy) endosperm (versus wrinkled or sugary) three pairs of genes have been described; su4 (Correns (1901) chromosome 4), su2 (Eyster (1934) chromosome 6) and su4 (Eyster, unpubl., chromosome 9). In a collection of cobs with F2-seeds, used for practical students courses, segregation followed the regular dihybrid scheme 9:3:3:1; the Fj-seeds being heterozygous for the genes C (chrom. 9) and su4 (chrom. 4). This proved that the population of F1-plants produced four types of embryosacs and four types of pollen in equal numbers (CSul5 Csuj, cSu4 and csuj.
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