Fifteen different variants of the topographic tetrazolium (TZ) testing were
examined in order to find a quick and reliable method for testing the viab
ility of Scots Dine seeds. The variants of the conventional TZ-method diffe
red in the area of cutting, premoistening before or after cutting and durat
ion of staining. The accelerated infiltration of the staining solution into
seed tissues under sub-atmospheric pressure was also tested. Good results
were attained with the conventional method when seeds were cut at both ends
before staining in a 1% 2,3,5-triphenyl tetrazolium chloride solution at 3
0 degrees C for 24 hours. In the vacuum method, dry seeds were cut at basal
and epical ends before de-gassing in a vacuum desiccator three times for 1
0 minutes at 23,6 kPa in a 1% tetrazolium solution. The best results were o
btained when seeds were completely soaked into stain while in the vacuum. S
taining was completed by incubating seeds in the staining solution at 30 de
grees C for four hours. The best vacuum and traditional TZ-methods gave sim
ilar results for the same seed lot of Scots pine. The vacuum TZ-staining ta
kes only 4 h 30 min, while the most efficient traditional method lakes 42 h
(time for cutting and evaluation of seeds excluded).