Abstract
The original tetraploid shoot of Fiveleaf Akebia was obtained by treating seeds with colchicine solution in spring of 1951 at Sakata's Plant Breed-ing Station in Chigasaki. Thereby several clonal individuals were isolated or propagated by the layering method. These tetraploid plants (2n=64) have showed larger, thicker, deeper-colored leaflets and thicker stems, but grown more slowlythan the normal diploid (2n=32). And the lightpurple col-ored inflorescences, which consisted of a few pi-stillate florets at the base and of several stamin-ate ones a tthe top part, appeared firstlyin spr-ing of 1956 on the matured tetraploid and diploid plants grown at the farm of the Utsunomiya University. Each organ of inflorescences of the tetraploid was distinctly enlarged in comparison. with that of the diploid, as shown in many other examples of the induced autotetraploid flower plants. Although the normal diploid plant did not bear fruit at all in spring of 1956, possibly, due to the genetical occurrence of self-incompatibility for seed production, the induced tetraploid succeeded in producing nice-shaped fruits. They are resulted probably from the fertilization of pollen of the diploid stamens with eggs of the tetraploid pistils. Hereafter the new tetraploid Fiveleaf Ake-bia will be suitable for the miniature or potted plants in the horticultural culture and also it will be a valuable material for the induction of the genetically interesting triploid plant.
