Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 155

Additional information on gene action is found in Supplemental Material 1 at the end of the regular chapters of the book. There are four types of gene action: additive, dominance, epistasis, and overdominance. Because gene effects do not always fall into clear‐cut categories, and quantitative traits are governed by genes with small individual effects, they are often described by their gene action rather than by the number of genes by which they are encoded. It should be pointed out that gene action is conceptually the same for major genes as well as minor genes, the essential difference being that the action of a minor gene is small and significantly influenced by the environment. A general way of distinguishing between these types of gene action based on interaction among alleles is as follows: