Table 4. Relationship of four root phenotypic traits and Si concentration with the FW or DW of the roots of rice seedlings treated with Si and SAR.

FW		DW
Linear regression equation	Correlation coefficient (R)	Linear regression equation	Correlation coefficient (R)
Y1 = 209.065X1-10.730	0.857**	Y1 = 1786.497X2-11.263	0.628**
Y2 = 149.933X1-2.154	0.926**	Y2 = 1350.104X2-3.299	0.763**
Y3 = 4.304X1-0.079	0.935**	Y3 = 38.526X2-0.110	0.761**
Y4 = 2187.111X1+10.271	0.755**	Y4 = 21374.533X2-25.011	0.743**
Y5 = 1789.5421X1-58.469	0.768**	Y5 = 18657.209X2-100.260	0.870**

Abbreviations: SAR, simulated acid rain; Si, silicon; FW, fresh weight; DW, dry weight; TRL, total root length; RSA, root surface area; RV, root volume; RTN, root tip number.

X₁ and X₂ represent the root FW and DW, respectively.

Y₁, Y₂, Y₃, Y₄ and Y₅ represent the RTL, RSA, RV, RTN and Si concentration, respectively.

^** Significant at the 0.01 level.