Question

By which of the following techniques, we can prove the phloem as an element for food translocation?

• A. Tracer technique
• B. Sap analysis technique
• C. Chemical analysis
• D. All of the above

Answer 1

The correct option is D All of the above

Translocation of organic nutrients is the movement of photosynthates from the region of source or supply to the region of sink or utilisation. Phloem (sieve tubes) is the pathway for this translocation as found out by stem girdling, stem puncturing, radioautographs using radioactive tracer isotopes and sieve tube analysis. Chemical study of phloem sap was done by Mason and Maskell (1928 - 34) who showed that if a plant is kept in dark there is decrease in sugar concentration of phloem cells.