Application of meta-Topolin for improving micropropagation of gooseberry (Ribes grossularia)

The aim of present study was to improve micropropagation of 14 gooseberry genotypes. The cytokinin metaTopoline (mT) significantly increased the number of microshoots long enough for roofing and eliminated the incidence of necrosis and leaf yellowing. The mean shoot number on the medium containing 0.5 mg dm(-3) mT increased from 1.8 to 2.8 compared to medium with benzylaminopurine (BAP). In the second subculture on mT medium a mean shoot number was 3.8 and probability of production of shoots > 1 cm increased from 0.18 to 0.44. In the same time shoot necrosis has fallen to zero in most cultivars. From the studied mT concentrations (0.25, 0.5 and 1.0 mg dm(-3)), the best effect for most genotypes was obtained at 0.5 mg dm(-3). The auxin indole3-acetic acid (IAA) or indole-3-butyric acid (IBA) added to the mT containing multiplication medium did not influence shoot number but in some genotypes generated tendency to necrosis. These results were reproduced during subsequent subcultures, thus enabling cyclic shoot multiplication.