Table 1.

Average enzymatic activities of ectomycorrhizal and non-Mycorrhizal root tips of poplar

(a) Comparison of the parents: P. trichocarpa (Pt) and P. deltoides (Pd)
	Mycorrhizal root tips		Non-mycorrhizal root tips
	Pt	Pd	Pt	Pd
β-xylosidase	25.43±1.67	14.04±1.17*	0.94±0.52	0.46±0.14
β-glucuronidase	23.29±1.82	35.47±1.47*	0.69±0.41	0.81±0.51
N-acetylglucosaminidase	297.83±13.86	412.81±17.72*	3.02±0.70	4.1±1.42
Cellobiohydrolase	86.51±2.21	22.42±1.61*	0.57±0.17	0.62±0.24
β-glucosidase	358.94±16.96	119.77±9.77*	4.13±1.47	2.78±1.45
Acid phosphatase	368.46±19.47	155.94±12.84*	25.33±5.15	25.77±4.47
Laccase	5.64±0.95	4.76±0.72*	0	0

(b) Comparison of the 40 plant genotypes (the two parents and the 38 progeny). Significant differences in enzymatic activities between mycorrhizal and non-mycorrhizal root tips are also reported
	n	Mycorrhizal root tips	Non-mycorrhizal root tips	Mycorrhizal versus non-mycorrhizal ratio
β-xylosidase	317	31.32±1.76*	1.23±0.07	25.5*
β-glucuronidase	317	41.41±2.90*	0.82±0.06	50.5*
N-acetylglucosaminidase	317	418.30±17.26*	3.14±0.16	133.2*
Cellobiohydrolase	317	85.07±6.48*	0.87±0.06	97.8*
β-glucosidase	317	306.78±16.93*	4.68±0.52	65.5*
Acid phosphatase	317	396.65±26.42*	24.81±1.35*	16*
Laccase	317	4.8±0.2	0	ND

Enzyme activities are expressed as pmol mm⁻² min⁻¹ (Courty et al., 2005). Mean and SE are given for each activity. An asterisk indicates a significant difference (P <0.001). The effect of plant genotype on enzyme activities was assessed for mycorrhizal root tips and non-mycorrhizal root tips.