Table II.

Comparison of cell length distribution in the meristem and in the mature region (leaf 7) of four Poa spp.

SpeciesCells with Length Outside a 2-Fold Size Range
25% Meristem length50% Meristem length75% Meristem lengthMature region
%
P. alpina 17 ± 324 ± 321 ± 420 ± 5
P. compressa 17 ± 518 ± 417 ± 316 ± 3
P. annua 15 ± 216 ± 320 ± 312 ± 3
P. trivialis 15 ± 311 ± 213 ± 210 ± 2

Cell length distributions were analyzed for each leaf (five combined epidermal cell files) in 100-μm intervals centered at 25%, 50%, and 75% of the estimated length of the meristem and in 1-mm intervals in the mature region. Data were averaged between leaves (n= 5) and mean ± se are presented. The values for each interval in the meristem were compared with those of the mature region with paired t test. In all of the cases the two-tailed Student's t test probability was not significant (P > 0.05). The proportion of cells with length lying outside a 2-fold range was calculated expressing the data as percentiles and repeatedly eliminating equal percentiles starting from the lowest and highest limit of the distribution, until the desired range was reached. The total number of cells in the intervals at 25%, 50%, and 75% of the length of the meristem and in the mature region were, respectively, 151, 129, 112, and 167 (P. alpina); 113, 88, 95, and 102 (P. compressa); 126, 105, 103, and 107 (P. annua); and 117, 113, 94, and 111 (P. trivialis).