Types of Genetic Environment Relationship

1. Linear or Additive relationship:

• When the phenotypic differences between the genotypes (G1 and G2) in two environment (E1 and E2) remain unchanged, it indicates linear relationship.
• The phenotypic values of two genotypes either increase or decrease in the changed environment (E2) in equal amount and the change is in same direction but equal in the phenotypic value of both the genotypes.
• Rank order of genotypes doesn’t change.

2. Non -linear or non-additive :

• When change in phenotypic values of two genotypes in changed environment is either in same direction but unequal resulting the change in rank order of genotypes.
• Or, when change in phenotypic values of two genotypes is in opposite direction, which may or mayn’t change rank order.
• this can be grouped into three types:

a. When the change is in same direction but unequal in magnitude with the change in environment. This leads to change in rank order of two genotypes.

b. When the change is in opposite direction but doesn’t change the rank order of genotypes.

c. When change occur in opposite direction but leads to change in rank order of two genotypes in the changed environment.