Please explain your question. density of root inner tissue, or density of whole root mass?

If you mean the density of the root mass in the soil or growing medium, the density of the root mass (RMD) is expressed as milligrams of dry roots per unit volume of the soil where the roots are located (mg Root Dry Weight/cm3 Sampled Soil Volume.

But the density of root is expressed as mg of Dry Root/Sampled Root Volume.

Thank you professor it's perfect

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Thank you professor