μM Zeatin Riboside Research Articles

Use of a Cytokinin Conjugate for Efficient Shoot Regeneration from Leaf Sections of Highbush Blueberry

Conditions for improving the efficiency of shoot regeneration from leaf sections of highbush blueberry (Vaccinium corymbosum L.) were investigated. Effectiveness of tissue culture medium supplemented with the cytokinin conjugate zeatin riboside or the cytokinin zeatin at 10, 20, or 30 μm was compared with medium supplemented with the optimum 2iP concentration of 15 μm. Use of 20 μm zeatin riboside resulted in the most shoots per leaf section, » 6-fold higher than the number of shoots produced on 2iP medium. The number of shoots produced on medium supplemented with zeatin was not significantly higher than the number of shoots produced on 2iP medium. Consequently, we concluded that the cytokinin conjugate zeatin riboside was more effective than either of the free cytokinins, 2iP or zeatin, in promoting shoot regeneration from leaf sections of highbush blueberry. Chemical names used: 6-(y,y-dimethylallylamino)-purine (2iP); 6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin).

In Vitro Propagation of the Rare and Endangered Grevillea scapigera (Proteaceae)

Micropropagation, including adventitious shoot growth from leaf sections, was achieved for Grevillea scapigera (Proteaceae), a rare and endangered species from Western Australia. Shoot tips were initiated on filter paper supports with liquid WPM (Woody Plant Medium) and supplemented with 20 μm zeatin riboside and 2 μm GA3. Shoots were then incubated on WPM solidified with agar and supplemented with 5 μm kinetin and 0.5 μm BA, which produced an approximate 6-fold multiplication rate per month. Up to three adventitious shoots were induced from 0.7-cm2 leaf sections after 6 to 7 weeks on solid 1/2 MS (Murashige and Skoog) medium supplemented with 10 μm BA and 0.5 μm IBA. Shoots, 30 to 50 mm long, were rooted in vivo in a fogged glasshouse under 70% shade using a commerical rooting powder [IBA, 0.1% (w/w)] applied to the base of the shoots. Most (67%) of the shoots treated in this way rooted after 5 weeks. Established, rooted plants have been grown on under glasshouse conditions. Chemical names used: N6-[2-isopentenyl] adenine riboside (zeatin riboside); gibberellic acid (GA3); 6-furfurylaminopurine (kinetin); N-(phenylmethyl)-1H-purine-6-amine (BA); 1-H-indole-3-butyric acid (IBA).