Multiple factors hypothesis' is given by

Multiple factor hypothesis' is given by Nilson Ehle.
A hypothesis to explain quantitative variation by assuming the interaction of a large number of genes (polygenes) each with a small additive effect on the character is a multiple factor hypothesis.
Nilsson-Ehle was a Swedish geneticist working on various cereal crops in 1909. Many of the characters that he examined yielded 3 : 1 ratios in the F2 generation following the cross of two parental strains, consistent with expectations for a single segregating locus with one allele completely dominant over the other.