R-script for calculation of times of tracheid differentiation

Abstract

The processes of xylogenesis are very often studied with use of repeated micro-sampling method. Microcores are taken throughout the growing season. After paraffin embedding and cutting on a rotary microtome permanent microslides are prepared. The numbers of cells (tracheids) are counted for each of the three zones – radially enlarging (G), maturing (D) and matured (T) zone of the developing growth ring. These numbers of cells are an input for the R script named WCDcalc that was developed for the calculation of durations and timing of cell differentiation in developing growth rings of softwoods. WCDcalc produces a plain text file as an output and a bar plot. For each cell there is a date in day of year format (DOY) that represents the day when the cell entered the particular zone, and the duration for which the particular cell was in the zone of the developing growth ring. The bar plot interprets results graphically in two forms. First, it is shown on the display, second, it is saved as an EPS file.WCDcalc is an R script written in R language. It can be run only in R environment. WCDcalc ( http://xylogenesis.wz.cz) was released under GNU General Public License.