Effect of cytokinins and sucrose concentration on the efficiency of micropropagation of ‘Zes006’ Actinidia chinensis var. chinensis, a red-fleshed kiwifruit cultivar

The effect of N 6 (3-hydroxybenzyl)adenine ( meta -Topolin— m T) was compared with that of N 6 -benzylaminopurine (BAP) and zeatin at the proliferation stage of micropropagation of red-fleshed Actinidia chinensis var. chinensis ‘Zes006’ in two separate experiments. Shoot number, shoot weight, leaf number and leaf area were significantly higher in m T-supplemented media compared with BAP or zeatin. When transferred to rooting media, plantlets that were propagated in m T-supplemented media readily produced roots, enabling easy acclimation to the greenhouse, whereas none of the plantlets propagated in BAP- or zeatin-supplemented media produced roots. Using 12 pairs of Simple Sequence Repeat primers designed for A. chinensis var. chinensis , a very low rate of somaclonal variation was detected at some loci in plantlets produced in zeatin- (1.04%), BAP- (0.4%) as well as in m T- (0.2%) supplemented media. Overall, m T in equimolar concentrations was the better cytokinin for tissue culture of ‘Zes006’ kiwifruit and may well be applicable to many other kiwifruit genotypes. Key message Supplementation of media with meta-Topolin for in vitro propagation of the red-fleshed kiwifruit cultivar ‘Zes006’ enhanced better shoot proliferation, giving healthy plantlets that were easier to acclimatize to the greenhouse environment compared with media supplemented with 6-benzylaminopurine or zeatin. It also induced a lower rate of somaclonal variation, as detected by SSR markers.