Table 2.

N₂-fixation capacity of 8-month-old D. odorifera seedlings grown in pots.

Treatments	Nodule numbers		Foliar δ15N (%0)		N concentration (%)		Nfixed (%)	Specific nodule activity (μg N mg−1 dwt nodule)
	N+	N−	N+	N−	N+	N−
Bradyrhizobium elkanii H255	9 ± 1 a, y	129 ± 10 a, x	−1.37 ± 0.05 a, x	−1.92 ± 0.10 a, y	3.40 ± 0.12 a, x	2.21 ± 0.19 a, y	57 ± 1 a	313 ± 13 a
Rhizobium multihospitium-like HT221	4 ± 1 b, y	45 ± 8 b, x	−1.41 ± 0.09 a, x	−2.15 ± 0.17 a, y	3.42 ± 0.15 a, x	1.94 ± 0.15 a, y	51 ± 4 ab	287 ± 26 a
Burkholderia pyrrocinia–like	6 ± 1 b, x	8 ± 1 c, x	−2.69 ± 0.34 b, x	−4.81 ± 0.57 b, y	3.93 ± 0.24 a, x	2.02 ± 0.24 a, y	48 ± 4 ab	269 ± 32 ab
No inoculation	4 ± 1 b, y	32 ± 3 bc, x	−1.33 ± 0.03 a, x	−2.15 ± 0.09 a, y	3.80 ± 0.16 a, x	2.04 ± 0.16 a, y	45 ± 1 c	203 ± 13 c

Mean data (n = 6) of each media treatment (in column) followed by the same letter (a, b, or c) are not significantly different among the inoculation treatments (P < 0.05); Mean data of each inoculation treatment (in line) followed by the same letter (x or y) are not significantly different among the media treatments (P < 0.05). For the plants used for the N₂-fixation measurements, foliar δ¹⁵N values were −0.61 ± 0.08 and −0.71 ± 0.21 for non-N₂-fixing B. polycarpa and Michelia macclurei, respectively. N₂-fixation was calculated by Eq. (1) using the averaged foliar δ¹⁵N values of these two non-N₂-fixing plants.