Table 3.

Correlations between select ions from MBMS spectra of P. trichocarpa leaves in the set from Boardman, OR and select metabolites as determined by GC/MS as well as lignin content, S/G ratios and the summation of metabolite-derived ions from MBMS spectra and the total aromatic metabolites determined by GC/MS

Trait	Lignin content	S/G	Sum metabolite ions in MBMSa	Aromatics by GC/MS
m/z 122	− 0.15	0.10	0.96	0.87
m/z 108	− 0.05	0.06	0.86	0.87
m/z 107	− 0.03	0.00	0.93	0.87
m/z 106	− 0.10	0.11	0.88	0.82
m/z 105	− 0.15	0.08	0.95	0.81
m/z 94	− 0.04	0.02	0.74	0.69
m/z 91	− 0.04	− 0.01	0.54	0.51
m/z 78	− 0.07	0.01	0.79	0.68
m/z 77	− 0.12	0.07	0.97	0.87
m/z 68	− 0.07	− 0.05	0.74	0.58
m/z 66	− 0.07	0.01	0.72	0.63
1,2,3-benzenetriol	− 0.11	0.06	0.43	0.50
1,2,4-benzenetriol	− 0.09	0.05	0.55	0.64
2,5-dihydroxybenzoic acid-2-O-glucoside	− 0.01	0.00	0.48	0.51
aromatics by GC/MS	− 0.13	0.09	0.88	1.00
benzoyl-salicyloylsalicin	− 0.12	0.06	0.67	0.49
catechol	− 0.03	0.02	0.52	0.62
phenol	− 0.06	− 0.01	0.64	0.68
salicin	− 0.01	0.03	0.61	0.72
salicyl alcohol	− 0.09	0.07	0.36	0.41
salicyl-coumaroyl-glucoside conjugates	0.04	− 0.11	0.70	0.62
salicylic acid	− 0.04	0.00	0.63	0.44
salicyltremuloidin	− 0.10	0.05	0.68	0.46
sum metabolite ions in MBMSa	− 0.13	0.05	1.00	0.88
tremulacin	− 0.12	0.03	0.63	0.47
tremuloidin	− 0.18	0.16	0.55	0.78
trichocarpin	− 0.06	− 0.01	0.49	0.50
trichocarpin conjugate	− 0.11	0.07	0.71	0.69
trichocarpinene	− 0.09	0.00	0.50	0.48

^aMetabolite ion intensities summed 68, 71, 77, 91, 94, 105, 107, 108, and 122