GGE Biplot Rebecca Nolan
What is GGE biplot? A software program designed by Weikai Yan GGE stands for Genotype main effect and Genotype X Environment interaction Scatter plot that plots both genotypes and environments in the same plot
What can it do? Show patterns in the data Identify the best or worst cultivars in certain environments Show relationships among environments Mega environments Show discriminating ability of an environment
What can’t it do? Show statistical significance Everything is relative Units mean nothing Take interesting pattern and go back to the original data to perform statistical analysis
What types of data can GGE biplot be use for? Genotype by environment data on a single trait – ex. Yield Genotype by trait two-way data- ex yield, height, and maturity Diallel cross data – ex identify good combining ability In fact any two-way matrix data can be done
How does it work? Principal component analysis is run on the data PC1 by PC2 is plotted Can look at other PCs PC1 represents mostly genotype effect PC2 represents mostly GXE interaction
How does it work? cont. What about the environment main effect? Removed before principal component analysis is done Expect there to be an effect, but it is not important from a breeder’s perspective
What can it do? Show patterns in the data Identify the best or worst cultivars in certain environments Show relationships among environments Mega environments Show discriminating ability of an environment
Where can I get the program? From Weikai Yan Website – http://ggebiplot.com Crop Sci 41:19-25 2001. Crop Sci 40:597-605 2000.