Plant genotype, juvenility and mechanisms of inhibition of rooting Persoonia virgata R. Br. cuttings

Persoonia virgata is an endemic shrub of Australia that is being bush-harve sted for its foliage and sold on the domestic and export flower markets. Th e limiting factor to the cultivation of many desirable Persoonia species ha s been the extreme difficulty in developing a reliable propagation system. This study investigated the effects of cutting type, maturity of the stock plant, and genotype, on the rooting of P. vilgata cuttings. It was found th at juvenile cuttings rooted significantly better than mature cuttings. Some juvenile seedling genotypes yielded no rooted cuttings, whereas others pro duced up to 90% rooting. No anatomical barrier to root formation was discov ered. High performance liquid chromatography showed differences in the abun dance of unidentified compounds in cuttings, related to season and to genot ypic differences in rooting abilities. A possible seasonal rooting inhibito r was present in some genotypes. The potential for selection of genotypes w ith improved rooting ability has been demonstrated.