Quantitative reduction of triphenyl tetrazolium chloride as a measure of viability in cereal seeds

Abstract

The reduction of 2,3,5-triphenyl tetrazolium chloride (TTC) to a coloured formazan derivative by dehydrogenase enzyme systems in viable seeds has been examined. TTC reduction occurs in dry but not wetmilled tissue and the coloured product could be extracted by any of several organic solvents. This formazan product was estimated spectrophotometrically at 480 nm. The influence of fineness of grinding the tissue, TTC concentration, period of treatment, sample size, vacuum infiltration of the milled tissue with TTC and of extracting solvent were examined and a standard procedure is suggested. Using this procedure, a close correlation between seed viability and TTC reduction was demonstrated. The advantages of this method over the widely used topographical method for estimating seed viability with TTC are discussed.