水分胁迫对苹果组培苗^(14)C-光合产物运输和分配的影响  

Effects of water deficiency stress on transport and distribution of ^(14)C-assimilates in micropropagated apple plants

作　　者：李天红[1] 李绍华[2] 王晶[3] 

机构地区：[1]中国农业大学农学与生物技术学院,北京100094 [2]中国科学院植物研究所,北京100093 [3]中国农业科学研究院原子能研究所,北京100094

出　　处：《中国农业大学学报》2005年第5期44-48,共5页Journal of China Agricultural University

基　　金：博士后科学基金资助项目(2004035080)

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-0.75 MPa)的1.42倍、中度胁迫(PEG渗透势为-1.5 MPa)的3.41倍、重度胁迫(PEG渗透势为-2.5 MPa)的10.18倍;且轻度和中度胁迫使叶片14C-光合产物的输出在24 h内分别达到48 h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。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 14C-assimilates by feeding ^14CO2. The quantity of exported assimilates from fed leaves was significantly reduced under water stress as compares with CK. The CK plants＇ export percentage of ^14C-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.？5 MPa）, respectively. Most of ^14C- assimilates was exported from the fed leaves within 24 h after feeding ^14CO2 under mild （94.22%） and moderate （93.95%） water stress, significantly higher than CK （55.65%）. 89.43% of labeled ^14C-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 ^14C-assimilates exported from fed leaves was found in the roots on severe stress. The distribution pattern of ^14C-assimilates among the various organs was modified by water stress, as the competitive power for assimilates （^14C-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.

关 键 词：苹果组培苗 水分胁迫 ^14C-光合产物 运输 分配 

分 类 号：S601[农业科学—园艺学] S661.1