Table 4. List of haplotypes with significant associations with wood quality and growth traits in the P. tomentosa association population (n = 460) after a correction for multiple testing.

Trait	P-value	Q-value	R2(%)	Significant Haplotypes	Haplotype Frequency	Single-Marker Associationsa
Lignin
	0.0012	0.0487	3.4	SNPs 2-4		—
				T-G-T	0.28
				G-A-C	0.18
	0.0052	0.0760	3.7	SNPs 44-46		SNP44 (lignin, Q = 0.0551)
				G-A-T	0.05
				T-A-T	0.27
α-Cellulose
	0.0019	0.0532	3.8	SNPs 1-3		SNP3 (α-cellulose, Q = 0.0629)
				T-G-A	0.25
				T-T-G	0.43
	0.0015	0.0487	2.8	SNPs 16-18		SNP18 (α-cellulose, Q = 0.0551)
				T-A-A	0.08
	0.0063	0.0922	5.6	SNPs 48-50		SNP49 (α-cellulose, Q = 0.0948)
				T-A-C	0.16
				T-C-A	0.17
Holocellulose
	0.0040	0.0713	3.0	SNPs 38-40		—
				T-G-A	0.12
	0.0023	0.0579	5.1	SNPs 44-46		SNP45 (holocellulose, Q = 0.0142)
				T-A-T	0.09
				G-C-C	0.13
				G-A-C	0.20
Fiber length	0.0051	0.0760	4.0	SNPs 89-91		—
				C-A-A	0.05
				G-G-A	0.29
Fiber width	0.0022	0.0579	3.2	SNPs 57-59		SNP59 (fiber width, Q = 0.0440)
				C-T-A	0.05
D
	0.0005	0.0187	2.7	SNPs 47-49		SNP48 (D, Q = 0.0454)
				C-A-C	0.21
				T-T-A	0.17
	0.0035	0.0673	2.6	SNPs 81-83		SNP81 (D, Q = 0.0454)
				C-T-A	0.30
V	0.0030	0.0611	3.9	SNPs 75-77		SNP75 (V, Q = 0.0035)
				T-T-A	0.11
				C-T-G	0.08

R² indicates percentage of the phenotypic variance explained. P-value indicates the significant level for haplotype-based association (the significance is P ≤ 0.05). Q-value indicates a correction for multiple testing (false discovery rate (Q) ≤ 0.10). D, diameter at breast height; V, stem volume.

^aSignificant single-marker associations with the lowest Q value (FDR Q ≤ 0.10) relating to the significant haplotype–trait association; /, no data were identified in this study.