Studies on the biometrical selective method. I. Quantitative expression of the breeding purpose.

Abstract

Up to now, the procedure in the selective method of rice breeding has been dependent on the breeder's experience and knowledge in almost all cases. It may be possible for the skilled breeder to select exactly some desirable plants or lines in a hybrid population, but it may not be so in general. Therefore, it is very important to systematize the selective method as an objective technique. Application of the selection index theory will be one way to solve this problem. However, in that case, it is necessary to decide how to evaluate the econornic value. This is fairly difflcult.