Table II.

Rate of primary root growth (V), length of fully elongated cells (le), average cell number in a cell file (Nm) of pericycle and cortical cells in the meristem, and the duration of the cell cycle (T) in the meristem of Arabidopsis estimated by the rate-of-cell production method (Ivanov and Dubrovsky, 1997)

Variables	Pericycle	Cortex
V, μm h−1	407 ± 14	407 ± 14
le, μm	203 ± 6	212 ± 6
Nm	39.0 ± 1.2	41.6 ± 1.2
T, h	13.6 ± 0.6	15.0 ± 0.6

Means ± se are given for nine roots, where Nm, V, and T were estimated for each individual root. For estimation of the average length of fully elongated cells (le), 73 pericycle cells in both the protoxylem and protophloem radii on sections of 10 roots (2–4 mm from the tip) and 50 cells of cortex on sections of nine roots were measured.