Table 3.

Growth characteristics of non-inoculated and mycorrhizal silver birches

Clone/ Line	T	Initial FW (g)	Final FW (g)	Ratio of final and initial FW	Root/shoot FW ratio	Number of adventitous roots	Length of adventitous roots (cm)
A	c	0.08 ± 0.04 a	1.75 ± 0.76 a	25.79 ± 19.90 a	0.80 ± 0.25 a	4.00 ± 1.33 a	16.70 ± 2.83 a
	ECM	0.07 ± 0.02 a	2.03 ± 0.76 a	34.49 ± 17.44 a	0.97 ± 0.24 b	4.00 ± 1.31 a	17.14 ± 1.04 a
23	c	0.15 ± 0.08 a	2.76 ± 0.88 a	23.75 ± 16.23 a	1.39 ± 0.40 a	4.97 ± 1.49 a	17.55 ± 3.78 a
	ECM	0.16 ± 0.09 a	3.06 ± 0.86 b	23.06 ± 13.63 a	1.59 ± 0.48 b	5.50 ± 1.72 a	17.59 ± 3.35 a
44	c	0.14 ± 0.06 a	2.70 ± 0.37 a	22.93 ± 9.28 a	1.40 ± 0.26 a	5.15 ± 1.54 a	18.64 ± 2.00 a
	ECM	0.15 ± 0.08 a	2.89 ± 0.51 b	23.28 ± 12.30 a	1.43 ± 0.29 a	7.68 ± 3.16 a	19.07 ± 2.10 a
65	c	0.17 ± 0.08 a	2.59 ± 0.43 a	17.70 ± 7.03 a	1.19 ± 0.20 a	4.03 ± 0.85 a	19.52 ± 2.05 a
	ECM	0.18 ± 0.09 a	2.83 ± 0.47 b	20.73 ± 11.90 b	1.26 ± 0.31 a	4.53 ± 1.22 a	18.52 ± 1.85 a

Effects of the mycorrhiza formation on the growth of silver birch control clone A and PtCOMT-modified lines 23, 44 and 65 after 8 weeks in co-culture with P. involutus in a greenhouse. Initial fresh weights (FWs) and final FWs of plants, root/shoot ratios, number and length of adventitious roots. Values are means ± standard deviations in the presence (ECM) or absence (c) of the fungus. Different letters following the values denote a significant difference (P < 0.05) between the non-inoculated and inoculated plants with mycorrhizas within each line/clone according to the Wilcoxon rank sum test or the two-sample t-test. Number of replicates 9-35.