The Canon of Potato Science: 7. Genotype-by-Environment Interaction

Studies on genotype-by-environment (GE) interaction are in the area of quantitative genetics. Genotype-environment interactions obviously play an important role both in the procedure of estimating various parameters and identification of patterns and trends of genotypes responding to environments observed from phenotypic data. Data generated in a biological experiment with a two-way factorial design in the form of a two-way table are useful for genotype-by-environment interaction studies. There are many kinds of two-factorial experiments with chosen levels of treatments carried out in field, storage or laboratory. An experiment on determining the most suitable spacing for planting a new variety, for example, would include two treatments which are levels of spacing between adjacent hills and those between adjacent rows inthe field. The levels are usually set up with equal numerical intervals within a range on distance. The two spacing treatments on the variety represent the two factors. A trial with m levels of hill spacing and n levels of row spacing consists of an m×n factorial combination of treatments. These treatments are tested with or without replicates according to suitable two-way factorial design for the type of field experiment. Data on traits responding to the treatments are gathered and put in the two-way table with, say, the IDs on the data columns being the labels for betweenhill spacing levels and those on rows for between-row spacing levels. Data from individual treatment combinations are recorded into the cells matched with their IDs of the columns and rows in the two-way table. A unique feature is that the levels chosen for each of the two factors are set up with predetermined series of magnitudes prior to experimentation based on conditions met with acceptable management practices for the crop. The goal is to compare and evaluate, separately and jointly, the response of certain quantitative trait(s) to the ‘serial’ effects of treatment levels in Potato Research (2007) 50:231–234 DOI 10.1007/s11540-008-9036-y