Abstract
Tetrazolium (TZ) assay is the fast evaluation for seed viability and alternative quick method for seed’s germinability (Porter et al., 1947; Wharton, 1955). All respiring tissues are capable of converting a colourless compound, TZ (2,3,5 triphenyl tetrazolium chloride) to a carmine red coloured water-insoluble formazan by hydrogen transfer reaction catalysed by the cellular dehydrogenases. TZ enters both living and dead cells but only living cells catalyse the formation of formazan which being non-diffusible stains the viable seeds red whereas the absence of respiration prevents formazan production making the dead seeds (aged tissue) remain unstained.The brief description of this protocol has been reported in Verma et al., 2013.
Materials and Reagents
Equipment
Procedure
Recipes
Notes
Acknowledgments
This protocol was adapted from Porter et al. (1947) and Wharton (1955). This work was supported by the Department of Biotechnology (grant no. BT/PR10262/GBD/27/77/2007) and National Institute of Plant Genome Research, Government of India.
References
If you have any questions/comments about this protocol, you are highly recommended to post here. We will invite the authors of this protocol as well as some of its users to address your questions/comments. To make it easier for them to help you, you are encouraged to post your data including images for the troubleshooting.
While germination test takes a longer time, TTC test is a quick alternative with comparable result. However, both tests can still be performed.
An option is to bisect the seeds longitudinally through the centre of the embryo. In that case, use 0.25% to 0.5% TTC instead of 1% TTC solution.
Hi Sanjoy, The seeds with germination percentage of 95% or more were taken as a positive control for the TZ assay. Thanks.
Hi Nwabisa, Distilled water should be autoclaved for 25-30 minutes at 121 degree Celsius (250 degree Fahrenheit) for sterilization. Thanks.
Hi Raghu, Another chemical test known for seed viability is Indigo Carmine (IC) test, it takes 2 to 30 hours for staining depending on variety of seeds. Here, only dead tissue takes the stain. IC staining has been reported for Pinus silvestris and Picea abies seed. Acid Fuchsin is another chemical for testing seed viability and it also takes 24 hrs for staining the non-viable tissue or embryos red (reported for orchid seeds). TZ has been widely accepted and reliable among chemical seed viability tests. Hope this helps you. Thanks.
Hi Emily,In this protocol, scarification solution with 0.1% of Triton X-100 was used. Recommended range for this surfactant is from 0.02% to 0.1%.