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Association (with a trait) by environment biplot

• Under the main menu 4-Way Data, click Trait Association by Environment biplot - Associations with a target trait. A trait selection device will appear on the top of the biplot, asking you select a trait as the target trait; other traits will be treated as "explanatory traits".

• GGEbiplot will generate a trait by environment two-way table, which consists of the correlation coefficients between the target trait and each of the explanatory traits in each of the environments. 

• The table will be printed to the log file and missing correlation coefficients will be replaced with '0'.

• A biplot will be generated based on this two-way table without any data transformations, i.e., using Model 5:

See Interpretation of a covariate effect biplot.

In depth: This TABE biplot is similar to a covariate-effect by environment biplot in that both are based on a explanatory variable (traits) vs. response variable (target trait measured in various environments) two-way table. The difference is that the explanatory variables in the later are genetic values, i.e., averaged across environments. Genetic values of explanatory traits are equivalent to genetic covariate such as genes, QTL, or genetic markers. In a TABE biplot, it is the phenotypic values of the explanatory traits that are used in calculating the "trait associations".