A series of directed crossings to test if the inheritance pattern of the trait matches multiple alleles. First visually different plants are crossed to create an F1; this generation is self-pollinated to create an F2 populations. In case of multiple alleles all F2 populations will segregate in a Mendelian 3:1 ratio, confirming that the three (or more) phenotypes relate to a monogenic trait.
Note:
This test may reveal epistasis (bigenic trait) instead of multiple alleles. Epistasis refers to two genes and therefore some populations (in F2, F3, etc) will segregate into three phenotypes.
RT: multiple alleles ↔ epistasis
BT: test