抄録
A new paddy rice cultivar named Aya was developed by the Hokkaido Prefectural Kamikawa Agricultural Experiment Station and was registered as a paddy rice Norin 309 in 1991. Aya has a dull (du) gene lowering the amylose content of endosperm starch and it is characterized by a good eating quality due to the low amylose content in Hokkaido, the northernmost island of Japan. Aya was derived from a cross between Eikei 84271 and Kitaake. Eikei 84271 has a du gene originating from NM391, a mutant line induced by lr-ray treatment of the seeds of a cultivar Nihonmasari. Kitaake is early maturity and is tolerant to cool injury. In this breeding program, anther culture method was used to shorten the breeding period.
