Table 4.

Anova results for the growth traits height growth rate (hGR, cm d⁻¹), total biomass (g), root mass fraction (g g⁻¹) and leaf succulence (g H₂O cm−²) (a) and for leaf ion contents (mmol g⁻¹ DW) (b) in split-plot experiments on the salt tolerance of the hybrid species Helianthus paradoxus and its progenitors Helianthus annuus and Helianthus petiolaris

		Source of variation
		Treatment	Errorwhole plot	Species	Population (sp.)	Treatment ×sp.	Errorsubplot
(a) Growth traits
	df	3	45–48a	2	6	6
hGR	SS	2317.9	996.2	1520.9	345.3	891.2	7255.8
	F	34.903***		13.214**	3.951***	10.195***	df = 475
Biomass	SS	5.096	7.029	48.292	3.996	12.685	79.329
	F	11.301***		36.255***	4.4330***	14.072***	df = 508
Root mass fraction	SS	3.735	3.735	33.893	18.120	6.772	31.478
	F	16.036***		5.611 ns	50.848***	19.003***	df = 498
Succulence	SS	641.6	476.4	56521.0	1126.0	201.00	5828.0
	F	21.518***		150.589***	17.072***	3.048**	df = 497
(b) Leaf ion contents
	df	3	27	2	6	6
Sodium	SS	279.78	26.65	680.86	14.93	30.04	149.91
	F	94.481***		136.720***	5.079***	10.221***	df = 295
Potassium	SS	15.757	5.915	162.890	17.678	77.680	57.667
	F	23.974***		27.645***	15.634***	68.700***	df = 297
Calcium	SS	9.214	7.413	8.458	7.756	11.233	34.414
	F	11.186***		3.270 ns	11.494***	16.647***	df = 296
Magnesium	SS	0.953	1.532	11.689	2.293	2.010	8.694
	F	5.600**		15.296**	13.449***	11.790***	df = 297
Sulfur	SS	3.531	1.084	302.151	6.265	5.481	14.44
	F	29.328***		144.700***	22.122***	19.353***	df = 295

Parentheses denote nested effects, asterisks stand for an interaction effect. The species effect was tested over the population mean square; all other effects were tested over the residual error. Effect significance levels:

^***P < 0.001;

^**P < 0.01;

^*P < 0.05; ns, not significant. SS, sum of squares. Error df are noted below the error SS for each anova.

^aWhole-plot error df were 45 for hGR and 48 for all other growth traits.