17.3.3 Ploidy Level Determination by Fow Cytometry
Figure17.3show the result offlow cytometry measurement with histogram and
plant sample. Controls containing 2C DNA showed peak 1 at the position (channel
50) that had been determined by analyzing the standards with known ploidy
(Fig.17.3). Tetraploids with 4C DNA showed histogram with peak 2 at channel
- The results obtained strongly indicated that no chimeras with both 2C and 4C
nuclei was produced from 0.2% w/v colchicine-treated apical meristem samples.
Flow cytometry was a helpful method for the determination of ploidy levels. It
was convenient and rapid and therefore it is recommended for identifying ploidy
levels in the plant breeding of polyploidCannabisplants. An important advantage
thatflow cytometry has over other methods, is its ability to detect mixoploids.
17.3.4 Morphological Characteristics
Variants in the morphological characteristics of leaf, stem andflower were observed
between 2and 4plants under the same growth condition. Tetraploid plants had
shorter leaves with increased leaf width, and the leaf index (leaf length/leaf width)
was decreased from 4.47 (diploid) to 2.68 (tetraploid) (Table17.2). However, the
tetraploid plants had larger maleflowers than the diploid plants (Fig.17.4). Flower
diameters of tetraploid and diploid plants were 1.1 and 0.4 cm (Table17.2)
respectively, and the difference was significant (P< 0.05).
Tetraploid plants height significantly decreased in comparison to diploid plants
(Fig.17.5) (Table17.3).
Transverse leaf section in tetraploid plants compared with diploid plants showed
that in general, the size of vascular tissue cells and palisade mesophyll cells in
Fig. 17.2 Stomatal parameters in diploid plants (a) and tetraploid (b) (40X, bar = 25μm)
374 H. Mansouri and M. Bagheri