Table 1.
PAC strains included in this study.
Table 2.
Factors and their two-fold interactions which are retained in the reduced model [1] for response variable ‘plant biomass’ including both hosts.
Figure 1.
Effects of ‘host’, ‘temperature’ and ‘fungal treatment’ on mean plant dry weight [g].
MYC = plants with mycorrhiza formed by Laccaria bicolor S238N; PAC = plants colonized by either one of the PAC strains (see Table 1); MYC&PAC = plants with both mycorrhiza and PAC colonization; Control = plants without any fungal treatment. Design plot drawn according to Crawley [60].
Figure 2.
The effects of ‘host’, ‘temperature’ and ‘fungal treatment’ on host dry weight and the root/shoot ratio.
Total host biomass is displayed as the sum of root (hatched) and shoot (empty) biomass. MYC indicates ‘mycorrhization’ by Laccaria bicolor S238N and letters A, B, C, and D inoculation with PAC strains A, B, C, or D (see Table 1). Panel (A) shows the data for Douglas-fir at 19°C, (B) for Norway spruce at 19°C, (C) for Douglas-fir at 25°C and (D) for Norway spruce at 25°C. Error bars show the standard error of the mean for root and shoot biomass. The root/shoot ratio is displayed as the mean for each fungal treatment and the control including the standard error of the mean. Different letters above the bars indicate significant differences in total biomass at α = 0.05 between treatments according to Tukey’s HSD.
Table 3.
Factors and their interactions which are retained in the reduced model [1] for response variable ‘plant biomass of Douglas-fir’.
Table 4.
Factors and their interactions which are retained in the reduced model [1] for response variable ‘plant biomass of Norway spruce’.
Figure 3.
Boxplots showing PAC biomass [g] depending on the ‘fungal treatment’, the ‘host species’ and ‘temperature’.
MYC indicates ‘mycorrhization’ by Laccaria bicolor S238N and letters A, B, C, and D inoculation with PAC strains A, B, C, or D (see Table 1). The plots are drawn according to Crawley [60]: The bold horizontal line shows the median. The bottom and top of the box show the 25th and 75th percentiles, respectively. The vertical dashed lines (‘whiskers’) show either the maximum value or 1.5 times the interquartile range of the data, whichever is the smaller. Points more than 1.5 times the interquartile range above or below the third or first quartile are defined as outliers and plotted individually, respectively. Different letters above boxes indicate significant differences between treatments; α = 0.05.
Figure 4.
‘Degree of mycorrhization’ by Laccaria bicolor S238N depending on ‘host species’, ‘PAC strain’ and ‘temperature’ (degrees of mycorrhization: 1 = 1–25% of the roots mycorrhized, 2 = 26–50%, 3 = 51–75%, 4 = 76–100%).
MYC indicates ‘mycorrhization’ by Laccaria bicolor S238N and letters A, B, C, and D inoculation with PAC strains A, B, C, or D (see Table 1). There are no significant differences between any two ‘fungal treatments’ within one ‘host’ and ‘temperature’. The plots are drawn according to Crawley [60].