Abstract
To demonstrate the advantages of dwarf characters in soybean, the Hyuga-dwarf line, a dwarf mutant induced from cultivar Hyuga by the application of ethyleneimine in 1975 was compared with Hyuga. The results obtained are summarized as follows: 1. Hyuga-dwarf line shows a slower vegetative growth rate than Hyuga in the quantitative characters such as main stem length and stem weight, whereas no significant differences have been detected between them in the qualitative characters such as total node number. 2. Hyuga-dwarf line has several advantageous characters in dry matter production and distribution, such as prolongation of leaf longevity, thickening of lamina and a high seed-stem weight ratio, when compared with Hyuga. 3. The dwarf character coded by a pair of gene is recessive to normal one. It is suggested that this gene expresses its character only at the top. In conclusion these results indicate that Hyuga-dwarf line has advantageous Harvest Index and Dry Matter Distribution Rate than Hyuga. It is suggested that productivity of the Hyuga-dwarf line higher than Hyuga will be obtained by improved cultivation methods, and further, that this gene will be a useful genetic resource for soybean improvement.
