Cannabis sativa L. - Botany and Biotechnology

tetraploid plants was significantly increased compared with diploid plants, but
intercellular air space declined in these plants (Fig.17.6).
The cross-section of the stem indicated that thickness of the xylem tissue of
tetraploid plants was much higher compared with diploid plants. On the contrary,
primary and secondaryfiber development in diploid plants was more (Fig.17.7).
Analysis also showed that increase in ploidy level and cell size caused a sig-
nificant decrease (20/93%) in density of glandular trichomes in tetraploid plants
than diploid plants (Table17.3).

Fig. 17.3 Flow cytometric analysis of surviving individualsCannabis sativaL. 50 days after
colchicine treatment of apical meristems of seedlings.aDiploid plant (control),binduced
tetraploid plant,cinduced mixoploid plant (i.e. containing diploid and tetraploid cells)

Table 17.2 Comparison of some morphological characteristics of pure diploid and tetraploid
cannabis

Flower diameter

(cm)

Leaf area index

(width/length)

Leaf width

(cm)

Leaf length

(cm)

Ploidy level

0.4 4.47 1.57 6.95 Diploid
1.1 2.68 2.32 6.21 Tetraploid

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      • Significant
        Represents significant at theP= 0.05 level by two-sample
      
      
      
      
    
    
    
    
  
  
  
  

17 Induction of Polyploidy and Its Effect onCannabis sativaL. 375