IN VITRO RHIZOGENESIS OF ROSA SP. IN DIFFERENT SUBSTRATES

Plantlets of Rosa cv. Rufa multiplied in vitro were transferred to rooting media both with and without saccharose. As substrates sand, expanded clay, perlite and vermiculite as well as two kinds of peat (TKS-1 and Floratorf) were used. The controls had cellulose as physical support in the rooting media. Control of rhizogenesis was done from 3 weeks of culture onwards.

The percentage of rooted plants obtained with expanded clay and Floratorf was very low (aprox. 15%). Most of the plants died.

With the culture medium containing saccharose the percentage of rooted plants was 100% in cellulose, sand and vermiculite; however, the number and size of the roots grown in each substrate were very different. When perlite and TKS-1 were used the average of rooted plants was 80%. Trials without saccharose gave good rooting results on sand, perlite and vermiculite.