Definition - What does Mutation mean?
A mutation of a grapevine is defined as a slight genetic variation, which commonly occurs among the many billions of cells of a grapevine. These can occur with clones via a random genetic mutation and create certain characteristics that make it no longer identical to its parent vine or clone.
Some mutations can be favorable, while others are not.
WineFrog explains Mutation
Genetic mutations of a grapevine can often occur due to their reaction to their environment, especially young clones. It is the plant's way of adapting. Mutations are common and have been part of creating new varietals and clones. Some include rot resistance, pigment alterations, frost resistance, etc.
For instance, mutations which created the variations of the color of grapes within the Pinot family have given the world of wine Pinot Gris and Pinot Blanc. The mutation was able to selectively shut down the genes that were responsible for the making of red pigments (anthocyanins).