Module: | Pollination & Outbreeding Devices
Q59: Consider the following statements regarding the artificial testing of pollen viability using TTC:
1. The viability of harvested pollen grains can be artificially verified in the laboratory using a chemical solution of 2,3,5-triphenyl tetrazolium chloride (TTC).
2. Viable pollen grains turn deep red or pink when treated with TTC because the chemical is reduced by the active dehydrogenases of cellular respiration.
3. Dead or non-viable pollen grains also turn red due to the passive, physical absorption of the TTC dye into the porous sporopollenin exine.
Which of the above statements is/are correct?
2. Viable pollen grains turn deep red or pink when treated with TTC because the chemical is reduced by the active dehydrogenases of cellular respiration.
3. Dead or non-viable pollen grains also turn red due to the passive, physical absorption of the TTC dye into the porous sporopollenin exine.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, whereas Statement 3 is incorrect.
For agricultural breeders and palynologists, testing whether stored pollen is still alive (viable) is a critical quality-control step.
The standard biochemical assay utilizes 2,3,5-triphenyl tetrazolium chloride (TTC). This is a colorless, water-soluble compound.
Causally, if a pollen grain is alive, it is actively respiring.
The dehydrogenase enzymes involved in its cellular respiration transfer electrons to the TTC, reducing it into a water-insoluble, deep red compound called formazan.
Thus, living pollen stains pink or red.
Statement 3 describes a false positive that does not occur in this specific assay.
Dead pollen lacks active dehydrogenase enzymes.
Therefore, no chemical reduction takes place, and dead pollen grains remain completely colorless, allowing researchers to easily calculate the percentage of living versus dead pollen in a sample.
For agricultural breeders and palynologists, testing whether stored pollen is still alive (viable) is a critical quality-control step.
The standard biochemical assay utilizes 2,3,5-triphenyl tetrazolium chloride (TTC). This is a colorless, water-soluble compound.
Causally, if a pollen grain is alive, it is actively respiring.
The dehydrogenase enzymes involved in its cellular respiration transfer electrons to the TTC, reducing it into a water-insoluble, deep red compound called formazan.
Thus, living pollen stains pink or red.
Statement 3 describes a false positive that does not occur in this specific assay.
Dead pollen lacks active dehydrogenase enzymes.
Therefore, no chemical reduction takes place, and dead pollen grains remain completely colorless, allowing researchers to easily calculate the percentage of living versus dead pollen in a sample.