Ty. Shen et Pc. Oden, Activity of sucrose synthase, soluble acid invertase and fumarase in germinating seeds of Scots pine (Pinus sylvestris L.) of different quality, SEED SCI T, 27(3), 1999, pp. 825-838
Two sub-lots were selected from a seed lot of Scots pine (Pinus sylvestris
L.) according to the size of embryos based on X-ray image. The germination
capacity (GC) and mean germination time (MGT) of these two sub-lots was 91.
5% and 6.6 days and 49.5% and 8.5 days. Each sub-lot was subjected to primi
ng at 30% moisture content plus GA,,, and 6-benzylaminopurine. The activiti
es of sucrose synthase, soluble acid invertase acid fumarase were determine
d and correlated with developmental degree and seed quality. Priming decrea
sed MGT by ca. 3 days. GA(4/7), 10(-7) M, increased the GC of poorly develo
ped seeds from 49.5% to 57.4%. The sucrose synthase activity of poorly deve
loped seeds was twice as high as that of well-developed seeds, indicating t
hat the poorly developed seeds were interrupted in their development during
maturation at a time when sucrose was still being transported into the see
ds. Sucrose synthase activity is therefore a potential indicator of the dev
elopmental degree (viability) of the seed. The activity of fumarase increas
ed during priming, indicating that one important effect of the pre-treatmen
t is an increased capacity for the mitochondrial degradation of stored lipi
ds in the embryo and megagametophyte. Fumarase activity in the seed can the
refore serve as an indicator of seed vigour.