| Studies on the induction of mutations by P32
in wheat : II. Some relations between chromosomal aberration and seed fertility in R2 generation Y. WATANABE and K. MUKADE Laboratory of Wheat Rust Resistance Tohoku National Agricultural Experiment Station, Morioka, Japan 278 R2 plants were divided into 4 classes according to the presence or absence of chromosomal aberrations or morphological variations as given in Table 1. Table 2 was compiled based on the relation between chromosomal aberration and seed fertility. Among plants with normal pairing of 21II, there were some individuals which showed low seed fertility less than 50% without accompanying any visible morphological changes, while there were some others with chromosomal aberrations which showed normal seed fertility as high as the control plants. This means that it is not safe to select plants in practical breeding only by the external characters or by the seed fertility without cytological examinations. |