Cutting propagation of Quercus acutissima clones after rejuvenation through serial grafting

Summary — Vegetative propagation of 34- to 67-year-old Quercus acutissima trees was success-fully achieved from rooted cuttings. Semi-hardwood ramets which were obtained from the clones es-tablished through grafting twice onto the 2-year-old rootstocks showed 60 % rooting (ranging from 20 % to 100%). After grafting only once, average rooting frequency was 11 % (ranging from 0 to 34%) using cuttings dipped in 500 ppm indole-butyric acid (IBA) solution. The rooting medium consisted of equal volumes of peatmoss and perlite. Cuttings were watered by intermittent mist and grown in the greenhouse at 25 ± 3 °C for more than 5 weeks. For rooting, there was no significant difference be-tween ortet age but marked differences were observed among the clones. Although most of the root-ed cuttings did not sprout new buds in the current year, they usually produced slowly-growing buds and/or revealed plagiotropic growth at the following year. Quercus acutissima / rejuvenation / serial grafting / semi-hardwood cutting Résumé — Bouturage de Quercus acutissima après greffage en cascade. La multiplication vé-gétative de Quercus acutissima âgés de 34 et 67 ans a été réalisée avec succès. Deux générations successives de greffage sur des porte-greffes de 2 ans ont permis d’obtenir des boutures semi-ligneuses manifestant un taux d’enracinement de 60 % (variation totale de 20 % à 100%). Après l