The regeneration of difficile lily protoplasts isolated from suspension cells of the Oriental hybrid lily (Lilium L.) cultivars Casablanca, Siberia and Acapulco was achieved by using the nurse-culture method. The divided protoplasts grew into colonies with nurse cells that have no regeneration ability, and developed to visible calli on a medium containing picloram. Many plantlets were formed on the calli after transfer of the proliferated calli to hormone-free medium. We were able to transplant the plantlets to soil in pots without acclimatization, and the plantlets grew in a greenhouse until flowering 2 years later.

Somatic hybridizations via electrofusion were performed in combinations of Oriental hybrid lilies (cvs. Acapulco and Shirotae) and Liliumxformolongi hort. (cv. Hakucho). Electrofusion-treated protoplasts divided only under nurse culture. The divided protoplasts grew into calli on the culture medium containing picloram, and the calli were then transferred to the hormone-free culture medium for induction of plant regeneration. The regenerants were transferred to a greenhouse, and were grown until the flower stage. In the fusion combinations of Acapulco + Hakucho and Shirotae + Hakucho, four regenerants apparently showed different morphological features compared with their parents. The results of molecular analyses by means of cleaved amplified polymorphic sequences markers and flow cytometry confirmed that these regenerants were somatic hybrid plants. Furthermore, we examined the stability of the morphological features of the hybrids in the next generations. This is the first report to describe the successful realization of Lilium somatic hybridization via protoplast fusion.

Onion (Allium cepa L.) seeds were primed for 4-6 days at 15°C on a filter paper moistened with trehalose or raffinose solutions. These priming treatments accelerated the speed and uniformity of germination, and were comparable to the polyethylene glycol (PEG) treatment, which is used widely as a priming technique. Onion seeds stored at 5, 15 and 22°C for 9 weeks after priming with trehalose or raffinose still showed high germination speed and uniformity. The priming effect of trehalose was observed in all three onion cultivars tested even though there were differences in the effect based on their original germination abilities. Under stressful conditions such as NaCl (100 mM), PEG (10%) or low temperature (15°C), primed seeds treated by trehalose (0.4 M) or raffinose (0.4 M) showed germination rates as high as 30-50% after 2 days incubation. This is in contrast with germination rates of around 2% in the unprimed seeds. From these results, the trehalose and raffinose treatments are considered useful to improve seed germination ability in onion seeds.

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