The importance of phenotyping

In any molecular genetics study, having a reliable phenotyping is a basic requirement to get a true conclusion. Without reliable phenotype data, all expensive molecular works are useless, because all conclusion will be false.

Mapping of grain yield under pre-flowering drought stress is especially prone to mistake. Fukai et al. (1999) reported that flowering time is a major determinant of grain yield under late season drought conditions. It is very important to control the variable flowering time among the tested lines to avoid escape. Garrity and O'Toole (1994) reported that staggered planting date was effective in synchronizing the flowering of test entries during the stress treatment period. Abandoning this major factor in a genetic mapping work will bring to a false conclusion, and this fallacy will be more obvious if the identified drought QTL is in the same region with QTL for flowering time.

The same thing will be happened for genetic mapping for any other trait, including disease resistance.