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

Abstract

The effect of N6(3-hydroxybenzyl)adenine (meta-Topolin—mT) was compared with that of N6-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 mT-supplemented media compared with BAP or zeatin. When transferred to rooting media, plantlets that were propagated in mT-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 mT- (0.2%) supplemented media. Overall, mT in equimolar concentrations was the better cytokinin for tissue culture of ‘Zes006’ kiwifruit and may well be applicable to many other kiwifruit genotypes. 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.