Table 3.

Results of linear mixed models for plant growth, biomass allocation and root bud characteristics

	TF	COV	Ploidy			Random effects
			LRT χ2	d.f.	P	LRT χ2	d.f.	P
Growth attributes
Plant height (cm)	–	TM	9.97	2	0.007	0	1	1
Branches	–	TM	13.66	2	0.001	0.01	1	0.917
Biomass allocation
Total mass (g)	–	–	11.54	2	0.003	0	1	1
Shoot mass (g)	–	TM	19.14	2	<0.0001	3.05	1	0.080
Inflorescence mass (g)	–	TM	17.03	2	<0.001	3.95	1	0.047
Root mass (g)	SR	TM	0.85	2	0.652	0	1	1
Root bud mass (mg)	SR	TM	2.71	2	0.257	0.12	1	0.724
Root bud mass/inflorescence mass (mg g–1)	FR	TM	8.85	2	0.012	2.88	1	0.090
Root bud attributes
Bud number	SR	RM	9.20	2	0.010	0.01	1	0.987
Individual root bud mass (mg)	FR	RM	2.49	2	0.288	0.01	1	0.904
Average bud height (mm)	LOG	RM	1.17	2	0.556	0	1	1
Average bud distance (cm)	LOG	RM	1.41	2	0.494	3.51	1	0.061
Minimum bud distance (cm)	LOG	RM	1.30	2	0.522	0.62	1	0.430
Maximum bud distance (cm)	LOG	RM	1.30	2	0.522	1.76	1	0.185
All root buds (n = 1929)
Bud height (mm)	LOG	–	0.20	2	0.905	577.99	2	<0.0001
Bud distance (cm)	LOG	–	237.39	3	<0.0001	292.02	2	<0.0001

Transformations (TFs) were performed on some variables to improve normality (SR – $\sqrt[2]{x}$, FR – $\sqrt[4]{x}$, LOG – log₁₀). Total plant mass (TM) or root mass (RM) were used as covariates (COV) in the models. Test statistics from mixed models of the effect of ploidy and random effects on each characteristic are shown with likelihood ratio tests (LRTs) between full and reduced models along with the P-value associated with the LRT. Random effects for models for mean bud height and mean bud distance include population and plant nested within population, while all other models include population only. Significant test results are in bold.