Table I.

Estimation of time between displacement of pericycle cells from the meristem to the first detected LRPs of three- and four-cell stage (Ti)

Stage of LRP DevelopmentVLgLeLpTeTbfTi
μm h−1 μm h
Three-cell (n = 9)362 ± 141,203 ± 57826 ± 514,402 ± 3244.6 ± 0.28.9 ± 1.013.6 ± 0.9
Four-cell (n = 5)349 ± 171,289 ± 51922 ± 445,509 ± 4615.3 ± 0.212.3 ± 1.616.0 ± 2.0

Three- and four-cell stages of LRP development can be interpreted as two- and three-cell stages (see legend, Fig. 2). The number of cells in the earliest LRP corresponds to the number of cells in a pericycle cell file, but not to the total number of LRP cells. V is the rate of root growth; Lg is the length of the growing part of the root (the sum of the length of the meristem and the length of the elongation zone); Le is the length of the elongation zone;Lp is the distance from the root meristem-root cap junction to the earliest-detected primordium; Te is the duration of cell elongation; Tbf is a time after cells had completed elongation and before a primordium formation. Each variable was determined for an individual root. Data are means ±se.