. 2023 Jun 10;23:309. doi: 10.1186/s12870-023-04312-w

Table 3.

Variance analysis of regression models fitting physiological and biochemical indices and coefficients for model precision

Traits	Relative water content (%)		Proline content (mg g^− 1 FW)		MDA content (mg g^− 1 FW)		Chlorophyll a content (mg g^− 1 FW)		Chlorophyll b content (mg g^− 1 FW)		Carotenoids content (mg g^− 1 FW)		Fv/Fm ratio
Model	Reduced cubic		Reduced quartic		Reduced cubic		Quadratic		Reduced cubic		Linear		Quadratic
	df	MS	df	MS	df	MS	df	MS	df	MS	df	MS	df	MS
Model	6	131.89^**	8	2.52^**	5	126.40^**	5	2.85^**	7	0.34^**	2	0.041^**	5	0.011^**
X₁ (NaCl)	1	56.51^**	1	0.95^**	1	51.81^**	1	4.62^**	1	0.0049 ^ns	1	0.072^**	1	0.025^**
X₂ (GABA)	1	8.42^**	1	0.41^**	1	0.24 ^ns	1	3.46^**	1	0.032 ^ns	1	0.0096^**	1	0.011^**
X₁ × ₂	1	342.72^**	1	0.70^**	1	310.59^**	1	5.54^**	1	0.0088 ^ns	-	-	1	0.0085^**
X₁²	1	13.93^**	1	6.76^**	1	30.19^**	1	0.32 ^*	1	0.11^**	-	-	1	0.00005^ns
X₂²	1	19.12^**	1	0.084 ^ns	-	-	1	0.23 ^ns	1	0.13^**	-	-	1	0.00004^ns
X₁² × ₂	-	-	1	0.53^**	1	9.43^**	-	-	1	0.11^**	-	-	-	-
X₁ × ₂²	1	9.20^**	1	1.82^**	-	-	-	-	1	0.13^**	-	-	-	-
X₁³	-	-	-	-	-	-	-	-	-	-	-	-	-	-
X₂³	-	-	-	-	-	-	-	-	-	-	-	-	-	-
X₁² × ₂²	-	-	1	2.03^**	-	-	-	-	-	-	-	-	-	-
X₁³ × ₂	-	-	-	-	-	-	-	-	-	-	-	-	-	-
X₁ × ₂³	-	-	-	-	-	-	-	-	-	-	-	-	-	-
X₁⁴	-	-	-	-	-	-	-	-	-	-	-	-	-	-
X₂⁴	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Residuals	23	1.00	-	-	24	1.05	24	0.068	22	0.0051	27	0.0005	24	0.00046
Lack of fit	2	1.54 ^ns	-	-	3	0.99 ^ns	3	0.15 ^ns	1	0.0013 ^ns	6	0.001^ns	3	0.00034 ^ns
Pure Error	21	0.95	21	0.029	21	1.06	21	0.056	21	0.0053	21	0.0004	21	0.00048
R²	0.97		0.97		0.96		0.89		0.95		0.83		0.82
Adjusted R²	0.96		0.96		0.95		0.87		0.93		0.82		0.79
Predicted R²	0.95		0.93		0.93		0.83		0.92		0.78		0.73

*p < 0.05 and ** p < 0.01; ^ns means not significant