Table III.
Shoot growth parameters and Zn content, number of trichomes, and grain production by the leaves of tobacco plants cultured in vitro for 3 weeks under three conditions (culture conditions given in Table I)
Each value is the mean of three individual measurements plus or minus sd. The number of trichomes and grain production were determined by VP-SEM observations.
| Treatment | Height of Shoot | Shoot Dry Weight | Zn Accumulation in Shoot | No. of Trichomes per cm2 of Leaf
|
Grain Production and Zn Excretion per Plant
|
||||
|---|---|---|---|---|---|---|---|---|---|
| Short Trichome | Long Trichome | No. of Grains | Size of Grains | Excreted Zna | Excreted Znb | ||||
| cm | mg | μg g−1 DW | μm | μg | % | ||||
| In vitro-control | 8.7 ± 0.56 | 171 ± 12.3 | 91.7 ± 12.2 | 21 ± 3.7 | 14 ± 2.3 | 127 ± 34 | 26 ± 11.2 | – | – |
| In vitro-Zn | 4.4 ± 0.33 | 80 ± 6.5 | 564.0 ± 36.2 | 56 ± 7.3 | 38 ± 4.2 | 784 ± 216 | 57 ± 12.8 | 4.1 | 9.2 |
| In vitro-Zn + Ca | 6.4 ± 0.45 | 97 ± 9.3 | 675.0 ± 33.5 | 43 ± 5.7 | 25 ± 6.3 | 1,223 ± 245 | 86 ± 13.2 | 11.0 | 16.9 |
a
Excreted Zn was calculated based on the number and size of excreted grains (Zn content was 2% in Zn grain, 1% in Zn + Ca grain, as estimated by ZAF method).
b
Percentage of excreted Zn was calculated based on Zn amount in shoot.