Involvement of abscisic acid in bulb dormancy of Allium wakegi Araki. II. A comparison between dormant and nondormant cultivars

The content of abscisic acid (ABA) in bulbs of two Allium wakegi Araki cult ivars, 'Kiharabansei No. 1' (dormant type) and 'Ginoza' (nondormant type), was similar and changed similarly during the development and storage of the bulbs. It increased during bulb development, reached a maximum shortly aft er bulb harvesting, and gradually decreased during bulb storage. The bulbs of 'Kiharabansei No. 1' showed dormancy correlated with the change in ABA c ontent, but those of 'Ginoza' did not show significant dormancy throughout the experimental period. The ABA content in the buds of dormant bulbs of 'K iharabansei No. 1' did not change after planting of bulbs, but that of nond ormant bulbs of 'Ginoza' planted on the same day rapidly decreased after pl anting. Application of ABA to bulbs delayed sprouting of both cultivars, bu t dormant bulbs of 'Kiharabansei No. 1' had higher sensitivity to ABA than the bulbs of 'Ginoza' or the bulbs of 'Kiharabansei No. 1' partly released from dormancy. These results suggest that the decrease in the ABA content a fter planting (watering) and low sensitivity to ABA are correlated with the nondormancy of 'Ginoza'.