Lipids were extracted from needles of Norway spruce plants of
different provenances. The plants, seeds of which were originally
collected from all over Europe, were grown at two sites in England at
the same longitude but one 350 km north of the other. Significant
correlations were observed between monogalactosyl diglyceride (MGDG)
and digalactosyl diglyceride (DGDG) ratios on the one hand and, on
the other, the lowest extreme winter temperature at the original site
of seed collection (EWTS).
In the case of lipid changes, however, environmental differences due
to site were more important than the inherent genotypic characteristics
of the planted trees while provenances with the lowest EWTS values had
more MGDG than DGDG. This implies that existing winter hardiness under
mild climatic conditions does not come from changes in this ratio
although DGDG formation from MGDG is known to be an important feature
of winter hardening in Norway spruce elsewhere in Europe. However,
closer analysis of the fatty acids in lipids from provenances at
individual sites did reveal significant correlations between those
provenances with low EWTS values and certain molar amounts or ratios of
fatty acids in DGDG, some of which could be traced to genotypic
expression. These partly involved the unusual Δ5
desaturations which are mainly confined to the fatty acids of those
conifers like Norway spruce that harden to very low
temperatures.