An alternative index for mutagenic efficiency
Ricardo Montalván and Akihiko Ando
Mutagenic efficiency was defined by Konzak et al. in 1965 as the ratio mutation/biological damage factor. His formula considers that mutagens always causes damage, but it has been shown that low doses of gamma-rays stimulate seedling growth. In this situation a negative value for damage is obtained with a negative mutagenic efficiency rate. This has no biological interpretation and the notion of range for mutagenic efficiency variation is also lost. An alternative index for mutagenic efficiency, which is a modification of the Konzak et al. 1965 formula, is proposed [mutation factor (1-damage/100)]. This index is more general, with known limits and positive results, thus overcoming some of the limitations found in the original formula.