Abstract
We examined the stability of phenotypic variations of root length(RL)in the seedling genration of a cross between Norin 1(large RL)and Konafubuki (small RL)in different growing seasons and soil water conditions. Seedlings were grown in pots in a greenhouse, and RL was measured when six leaves were expanding. Mean RL largely differed among the environments, i.e., larger in the summer crop season than in the winter crop season and larger in the moderate water condition than in the dry of wet soil condition. The pattern of phenotypic variation of RL was similar, however, in all environments. The distribution of RL had a large peak in the smaller side, and the seedlings seemed to be separated into two groups, small RL and large RL. These results indicate that the pattern of phenotypic variation of RL in the seedling generation of the hybrid population is relatively insensitive to growing seasons and soil water conditions, suggesting that a selection of RL in the seedling generation may be possible in any of these growth conditions.
