Abstract
(1) The authors succeeded in breeding a cucumber of good quality, bearing fruits at most node all the year round.
(2) The varieties used in this breeding were Suyo, Manshuaki and Ochiai No. 1. Suyo is a summer variety belonging to the North Chinese group. The nature of fruit bearing is not affected by day-length and temperature. Flesh is of very .good quality. Manshuaki belongs to the same group that Suyo does. The fruits bear at most node all the year round, but the veins are very feeble. Ochiai No. 1 is a spring variety belonging to the South Chinese group that is sensitive to day-length and temperature; under only short day and low temperature condition the fruits are borne at most node, and the veins are thick and vigorous.
(3) Suyo was crossed by Ochiai No. 1 in 1946 and the other Suyo was crossed by Manshuaki in 1947, and line separation of their progenies continued in summer cultivation. The F4 Suyo×Ochiai No. 1.21-6 S-10-2 had 60% in the female node ratio of the main vein. The veins were thick and strong, but somewhat dwarf. On the other hand, the F3 Suyo×Manshuaki 22-4 S-2 had 70.2% in the female node ratio. The veins were slender and feeble. To breed for more vigorous variety 21-6 S-10-2-6 was crossed by 22-4 S-2-7, and line separation was repeated. In 1953, two lines of F3 (F4 Suyo×Ochiai No. 1)×(F3 Suyo×Manshuaki) fixed most important characters; the female node ratio was raised to 84. 3% and 82.0%, veins were strong and thick, and flesh was of high quality. The results of the ecological study in 1954 show that this variety is insensitive to day-length and temperature, and fruit bear at most node.
(4) This variety will force the development of the cultivation of cucumber and will be expected to be used as a parent of F1 hybrid for extensive utilization.
