Effects of Cytokinin

1. Cell Division. Cytokinins are essential for cytokinesis though chromosome doubling can occur in their absence. In the presence of auxin, cytokinins bring about-division even in permanent cells. Cell division in callus (unorganised, undifferentiated irregular mass of dividing cells in tissue culture) is found to require both the hormones. 

2. Cell Elongation. Like auxin and gibberellins, cytokinins also cause cell elongation. 

3. Morphogenesis. Both auxin and cytokinins are essential for morphogenesis or differentiation of tissues and organs. Buds develop when cytokinins are in excess while roots are formed when their ratios are reversed (Skoog and Miller, 1957). 

4. Differentiation. Cytokinins induce plastid differentiation, lignification and differentiation of interfascicular cambium. 

5. Senescence (Richmond-Lang Effect). Cytokinins delay the senescence of leaves and other organs. 

6. Apical Dominance. Presence of cytokinin in an area causes preferential movement of nu-trients towards it. When applied to lateral buds, they help in their growth despite the pres-ence of apical bud. They thus act antagonistically to auxin which promotes apical dominance. 

7. Seed Dormancy. Like gibberellins, they overcome seed dormancy of various types, including red light requirement of Lettuce and Tobacco seeds. 

8. Resistance. Cytokinins increase resistance to high or low temperature and disease. 

9. Phloem Transport. They help in phloem transport. 

10.Accumulation of Salts. Cytokinins induce accumulation of salts inside the cells. 

11.Flowering. Cytokinins can replace photo periodic requirement of flowering in certain cases. 

12.Sex Expression. Like auxins and ethylene, cytokinins promote femaleness in flowers.

13.Parthenocarpy. Crane (1965) has reported induction of parthenocarpy through cytokinin.