5. NMRで診たチューリップ球根の休眠打破における低温要求の意義(セミナー「生体・食品の構造と機能に関する低温生物工学の展開」)

概要

論文の詳細を見る
Tulip bulbs require a low temperature period to activate dormancy breaking. To elucidate factors on dormancy breaking induced by low temperatures, changes in dynamic states of water in tulip bulb tissues were non-destructively determined by proton density and spin-lattice relaxation times (T_1) images using MRI. The low temperature treatment increased signal intensity of mobile water in the inner part of the scale parenchyma tissue whereas no mobile water was observed in noncooled bulb scales. On the contrary, water mobility in the epidermal system containing aquiferous (water storage) tissue of the scale was higher in the noncooled bulb while no signal was observed in the precooled bulbs. Furthermore, the long fraction of spin-spin relaxation time (T_2) increased to about 75% in the scale parenchyma tissue in the precooled bulb, while it remained about 60% in the noncooled ones. Although no difference in total amounts of water content was observed in the whole bulbs stored at both temperatures, a significant increase of water content in the inner part of the scale parenchyma tissue was observed in the precooled bulb. Further, the respiration rate of the whole precooled bulbs during the storage period was suppressed to as low as half that of the noncooled bulbs. And the sugar accumulation of the precooled bulb scales was twice that of the noncooled bulbsn. Therefore, water status detected by NMR suggested that water migration from the aquiferous tissue of epidermal system to the inner part of the scale parenchyma occurs through higher osmotic pressure (Ψ_π) resulting from higher sugar accumulation during cold storage. When the precooled bulbs were transferred to 20 ℃, the treatment resulted in a threefold increase in respiration as compared with noncooled bulbs. These results suggest an effect of water redistribution in scale parenchyma tissue during cold storage. In succession, higher water production resulting from higher respiration in the precooled bulbs when transferred to ambient temperatures encouraged metabolic activity. These synergistic effects in water status would lead to rapid growth of the flower stalk after planting.
低温生物工学会の論文
1998-08-25

5. NMRで診たチューリップ球根の休眠打破における低温要求の意義(セミナー「生体・食品の構造と機能に関する低温生物工学の展開」)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク