Contents - Index
Functions for genotype by environment data
There can be many different models for biplot analysis of a genotype-by-environment two-way data, and different models have different interpretations and utilities in understanding the data.
For the purpose of genotype evaluation, GGE biplots , i.e., biplots based on singular value decomposition of environment-centered should be used. Such environment-centered data can be further scaled in different ways, leading to different GGE biplots.
A GGE biplot can be used not only in evaluating the genotypes, but also in evaluating the test environments for their usefulness/effectiveness in genotype evaluation. Follow the links below for a complete example of biplot analysis of genotype-by-environment two-way data (read entries as genotypes and testers as environments):
Biplot analysis of genotype by environment data include three major aspects (see Yan et al., 2007, Crop Science, 47: 643-653)
Note: If you are only interested in understanding the genotype-by-environment interactions, the double-centered model should be used. However, I really don't see any use of this model in genotype evaluation or test environment evaluation or in plant breeding in general. In fact, in my opinion, publications that are devoted to the analysis of GE only are more misleading than helping.