应用^(14)C和^(15)N研究多效唑对椪柑幼树的生理效应

Physiological eflects of PP_(333) on yonny Pon-Kan trees

用^(14)C喂饲法测定多效唑对椪柑幼树光合作用强度、同化产物运转与分配的影响。结果表明,多效唑处理能促使椪柑叶片叶绿素含量升高,光合作用增强;并能调节同化产物的分配,使其向根系转移增多,向新梢运转减少。^(15)N示踪试验结果表明,多效唑处理能使椪柑根系增生,吸收^(15)N增多,但却抑制根系中的氮向植株其它器官的转移,使更多的氮累积在根系中。

effects of PP_(333) on photosy nthesis intensity and transportation of assimilates in young Pon—Kan trees were investigated by using the method of ^(14) C-feeding.Results indicated that application of PP_(333) could increase the chlorophyll content in Pon-Kan leaves, improve the photosynthesis intensity and control the distribution of assimilates making more assimilates transfer to the root system and inhibit the tranportation of ^(14) C—assimilates to new growth branches.There were no obvious effects on the total output of the assimilates in the leaves. The results of ^(15) N tracer experiment showed that the trees treated with PP_(333) could enlarge the root system and expand the ^(15) N absorption capacity.However, most of the absorbed nitrogen accumulated in the roots which suggests that PP_(333) application could inhibit the transportation of nitrogen from the root to the other parts of the plant.