Multiple factor inheritance (polygenic inheritance or quantitative inheritance) implies that several pairs of alleles are interacting and that each has a similar and measurable effect on the characteristic. Experimental evidence for polygenic inheritance was first obtained by a Swedish geneticist. H. Nilsson Ehle in 1908. He found that kernel colour in wheat is determined by three gene pairs. The phenotypic ratio in quantitative inheritance of a dihybrid cross will bel: 4:6:4:1.1:2:1 is the phenotypic ratio of incomplete dominance in Mirabilis jalapa. 9:3:3:1 is the dihybrid phenotypic ratio or law of independent assortment.