Grafting compatibility between variants of sandalwood (Santalum album Linn.) in Gunungkidul, Indonesia

Abstract

Abstract The declining number of adult individuals led to changes in the mating system of certain sandalwood (Santalum album Linn.) populations previously dominated by outcrossing. The genetic quality of the produced seeds and reproduction success decreased due to inbreeding. Therefore, vegetative propagation by grafting is an alternative method to support sandalwood conservation and development. This study aimed to determine the compatibility of rootstocks and scion for vegetative propagation by top cleft grafting on sandalwood variants found in Petir and Wanagama landraces, Gunungkidul Regency, Indonesia. Based on the availability of materials, we used Red Big Flower (RBF), Red Small Flower (RSF), and Yellow Small Flower (YSF) variants, with RBF and RSF as rootstocks and RBF, RSF, and YSF as scions. All six combinations of rootstock-scion indicated compatibility with various results. The average grafting survival was 35.8%, and the RBF-YSF combination showed the highest survival (90%). However, the RSF-YSF combination produced leaves on the scion at most (21 blades). The propagation method of grafting can be applied for the conservation and deployment of sandalwood variants. In tree improvement, grafting is essential to set up the stool plant in a hedge orchard, copy the genetic materials for the clonal test and clonal seed orchard.