Acta Univ Latv (2004) 676: 235–237

In vitro induction of polyploidy in Ribes

Abstract

To restore the fertility of interspecific currant hybrids and to obtain tetraploidic varieties, we investigated currant polyploidization in vitro using microshoots and isolated embryos. Explants of Ribes nigrum, R. hudzonianum, R. aureum, R. americanum, R. uva-crispa and their hybrids were used for the studies. Explants were treated with colchicine and orysalin solutions in various concentrations. Colchicine (0.25 %), to a lesser extent than orysalin (from 20 to 40 μM), decreased the vitality of isolated microshoots of currants and the output of rooted plantlets. Systems of isolated embryos and microshoots are equally effective for creating polyploids currant. Chimeric plants were obtained during polyploidization in vitro. The total number of regenerants decreased with polyploidogen treatment, but the total number of regenerants with a higher number of chromosomes did not depend on the kind of polyploidogen and its concentration. The biggest output of regenerants was obtained by treating isolated explants with 20 μM orysalin. The frequency of regeneration after polyploidogen treatment reached 19.3 % from embryos and 32.3 % from microshoots.