| 摘要: |
| 通过调节PEG（6000）溶液的渗透势模拟不同程度水分胁迫条件，研究其对“红富士”苹果组培苗^14C-光合产物运输和分配的影响。结果表明，1）水分胁迫使饲喂叶中^14C-光合产物输出百分率显著下降：试验结束时对照^14C-光合产物输出率为轻度胁迫（PEG渗透势为-0．75MPa）的1．42倍、中度胁迫（PEG渗透势为-1．5MPa）的3．41倍、重度胁迫（PEG渗透势为-2．5MPa）的10．18倍；且轻度和中度胁迫使叶片^14C-光合产物的输出在24h内分别达到48h的94．22％和93．95％，显著高于对照（55．65％），在时间上表现得更为集中。2）正常水分条件下，苹果叶片输出^14C-光合产物的89．43％运往地上部，仅10．57％运往根部，重度胁迫则使高达64．78％的^14C-光合产物运往地下部；地上部、特别是茎尖对光合产物的竞争能力（^14C-分配系数，K）由对照的3．42显著下降至不同程度水分胁迫处理后的1．30～0．48，其对光合产物的竞争能力显著下降；而地下部、特别是细根^14C-分配系数由对照的0．16增加至0．82～1．26．其获取光合产物的能力显著增强。 |
| 关键词: 苹果组培苗 水分胁迫 ^14C-光合产物 运输 分配 |
| DOI：10.11841/j.issn.1007-4333.2005.05.130 |
| 投稿时间：2005-03-22 |
| 基金项目:博士后科学基金资助项目（2004035080） |
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| Effects of water deficiency stress on transport and distribution of 14C-assimilates in micropropagated apple plants |
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| Abstract: |
| Micropropagated 'Fuji' apple plants were used to study the effects of water stress at different deficit intensities by regulating the osmotic potential of the solution with PEG-6000 on transport and distribution of()~(14)C-assimilates by feeding()~(14)CO_2.The quantity of exported assimilates from fed leaves was significantly reduced under water stress as compares with CK.The CK plants' export percentage of()~(14)C-assimilates of was 1.42,3.41,and 10.18 times as compared with mild stress(solutions with osmotic potential of-0.75?MPa),moderate stress(solutions with osmotic potential of-1.5?MPa), and severe stress(solutions with osmotic potential of-0.75?MPa),respectively.Most of()~(14)C-assimilates was exported from the fed leaves within 24 h after feeding()~(14)CO_2 under mild(94.22%) and moderate(93.95%) water stress,significantly higher than CK(55.65%).89.43% of labeled()~(14)C-assimilates exported from the leaves within 48 h after feeding leaves were distributed in the above-ground part of the micropropagated plants under a normal water status.About 64.78% of()~(14)C-assimilates exported from fed leaves was found in the roots on severe stress.The distribution pattern of()~(14)C-assimilates among the various organs was modified by water stress,as the competitive power for assimilates(()~(14)C-distribution coefficient,K) of the above-ground part,especially shoot apex was significantly decreased,and the sink ability of roots particularly the fine roots had a stronger power to compete for assimilates. |
| Key words: micropropagated apple plants water stress ^14C-assimilates transport distribution |
