An improved fluorescein diacetate (FDA) biochemical viability test was deve
loped for jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (M
ill.) B.S.P.) and white spruce (P. glauca (Moench) Voss) seed. The changes
to improve the FDA test were slicing the seedcoats prior to soaking in the
stain, increasing the FDA stain concentration from 0.2% to 2.0% and adding
a 45 minute incubation period (after the FDA stain soak) to the procedure.
The improved FDA test estimated the seed lot viability (measured as percent
age germination) to within +/- 5 for most seed lots and to within +/- 10 fo
r the remaining seed lots of the three species. Visual numerical ratings us
ed to estimate embryo viability for the FDA test were highly correlated (r(
2)=0.98) with the amount of extractable fluorescein found in jack pine embr
yos. The amount of extractable fluorescein in whole black spruce seeds incu
bated with FDA solution was also highly correlated (r(2)=0.98) with the pro
portion of live seeds. These results suggest that the FDA test is an altern
ate viability test for jack pine, black spruce and white spruce seed.