Megumi Hamano

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 cultivars, ‘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 after bulb harvesting, and gradually decreased during bulb storage. The bulbs of ‘Kiharabansei No. 1’ showed dormancy correlated with the change in ABA content, but those of ‘Ginoza’ did not show significant dormancy throughout the experimental period. The ABA content in the buds of dormant bulbs of ‘Kiharabansei No. 1’ did not change after planting of bulbs, but that of nondormant bulbs of ‘Ginoza’ planted on the same day rapidly decreased after planting. Application of ABA to bulbs delayed sprouting of both cultivars, but 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 after planting (watering) and low sensitivity to ABA are correlated with the nondormancy of ‘Ginoza’.

Strawberry cultivar identification based on hypervariable SSR markers

We genotyped strawberry cultivars by two newly selected and two previously reported SSR markers. All four markers produced interpretable electropherograms from 75 accessions consisting of 72 Fragaria × ananassa cultivars or lines and three octoploid Fragaria species accessions. These SSR markers were highly polymorphic; in particular, one of the newly developed markers, FxaHGA02P13, was capable of distinguishing all of the accessions except for a mutant strain that was derived from another accession in the set. When two markers were combined, all 48 full-sib individuals could be distinguished. Fingerprinting patterns were reproducible between multiple samples, including the leaves, sepals, and fruit flesh of the same accession. Principal-coordinate analysis of the 75 accessions detected several groups, which reflect taxon and breeding site. Together with other available markers, these SSR markers will contribute to the management of strawberry genetic resources and the protection of breeders’ rights.