ABSTRACT

This chapter demonstrates the numerous utilities of genotype and genotype-by-environment (GGE) biplot in visual analysis of genotype-by-trait data. These include: 1) evaluating cultivars based on a single trait; 2) evaluating cultivars based on two traits; 3) comparing cultivars as packages of traits; 4) visualizing merits of a cultivar; 5) visualizing defects of a cultivar; 6) visualizing interrelationships among traits; 7) identifying traits that are closely associated with, and therefore can be used in indirect selection for, a target trait; 8) independent culling based on single traits; 9) investigating different selection strategies; and 10) achieving systems understanding of the crop under study. Wheat end-use quality datasets are used to illustrate these points. Two concepts of plant breeding, i.e., independent culling and systems understanding of crop improvement, are discussed after illustrating some of the functions of the GGEbiplot program. This chapter is not only of importance for those interested in visual analysis of genotype-by-trait data, but it also is particularly important for those interested in breeding for wheat end-use quality, methodology of plant breeding, and systems understanding of crop improvement.