环剥及外源激素对柑桔光合产物运转分配的影响

Effects of Girdling and Exogenous Plant Hormones on Translocation and Partitoning of Photosynthates in Citrus

以枳砧温州蜜柑为试材，应用14C示踪技术，研究了环剥及外源激素对柑桔叶片光合产物运转分配的影响，结果表明：环剥和环切均能阻止环剥（切）口上方叶片的光合产物向环剥（切）口下方的运输对1a生柑桔主于环剥1mm宽，环剥伤口大约在20d接通；主于环切2圈后，环切口愈合接通则需要10～20d时间。但刚接通的伤口对光合产物的运输效率并不高，要完全恢复其运输功能，则需要更长的时间。激素对柑桔光合产物运转分配的影响与激素种类和植株的生长发育状态有关。旺盛生长的幼叶应用GA和BA后，能明显增加光合产物的输入；而应用ABA后，有减少光合产物输入的趋势。成熟叶片应用以上3种激素后，仅能改变标记叶光合产物向根系的分配，而不能使应用叶本身输入光合产物。GA能影响到与处理枝条相邻近的枝条，而BA的作用范围则仅限于应用枝条本身。

By applying the 14C tracer technique,the effects of girdling,ring-cutting and ex-ogenous hormones on the translocation and partitioning of photosynthates in citrus werestudied. The plant materials used were 1-year-old field seedlings trees of satsuma mandarine(Citrus unshiu Marc. on Poncirus trdeliata Raf. ). The main results were summarized as fol-lows, both girdling and ring-cutting prevented translocation of photosynthates from leaves lo-cated above the site of operation. For the treatment where a ring of bark 1 mm in width onthe trunk of a 1-year-old seedling was removed, approximately 2O days were required tobridge up the gap in the interrupted bark and reestablish the connection between vasular tis-sues on both sides of the ring. Reunion after ring-cutting necessitated 10~20 days after theoperation. Rate of transport through the reunion tissue was initially low and a longer timehad elapsed before the function of transportion was fully recovered. The effect of plant hor-mones on translocation and distribution of photosynthates was dependent on the kind of hor-mone and the status of plant growth and development. GA and BA,when applied to vigorous-ly growing young leaves,significantly increased the import of photosynthates ito the treatedleaves. On the other hand,application of ABA to leaves tended to reduce import rate, Theabove effect of GA could even spread to some nearby shoot,while the effect of BA was re-stricted to the shoot whose leaves were treated. Applying the three above-mentioned hor-mones to fully matured leaves could to a certain extent alter only the partitioning of labelledphotosynthates to the root system,but failed to induce import of labelled photisynthates intothe treated leaves.