We tested pollen viability of eight species using
four vital dyes, a new peroxidase test together with
three other established methods (MTT, Baker’s and
X-Gal), to determine their potential to differentiate fresh
pollen from pollen heated for 2 h and 24 h at 80°C
(killed pollen) and compared the results with in vitro
germination. We found that two of three dyes previously
employed to determine viability also stained killed pollen,
while the new peroxidase test and MTT did not. We
suggest that the latter two are the best methods to test
pollen viability, since they do not normally stain either
killed or aborted pollen.