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Weeks after inoculation Weeks after inoculation
Figure 2.--Vertical progress in reaction zone size (upper row) and fungal growth (lower row) in Scots pine phloem in
sterile control (triangle), in an experiment in France (left) and Sweden (right). Tree provenances were pooled.
response to artificial inoculation with a French (circle) and Swedish (square) strain ofL. wingfieldii as well as a
Samples were taken after 3, 6 and 21 (France) or 24 (Sweden) weeks. Numbers of observations (trees) were 5 and 6
(France and Sweden, respectively) for the first two sampling dates, and 3 for last sampling date at both sites. Vertical
bars indicate standard error.
in the native provenance "Ki!". No significant differences were observed between treatments, except for the 21 week
sampling date at Nogent-sur-Vernisson, where the French strain of L. wingfieldii grew further than the Swedish strain.
However, in the Spanish provenance, that was also true for all sampling dates. In both locations, fungi expanded rapidly
during the first 3 weeks, and thereafter stabilized (Fig. 2). At Nogent-sur-Vernisson, fungus expansion was higher for the
French than for the Swedish strain after 21 weeks. The expansion of the Swedish strain even decreased at 21 weeks, except
in the Pyrenean provenance (Fig. 3).
17l