Morphological variation in the interspecific hybrid of Acacia (Acacia mangium × A. auriculiformis)

Abstract

Acacia hybrid is an interspecific hybrid resulting from crossing between Acacia mangium and A. auriculiformis either naturally or artificially. This study aimed to determine the morphological variation of artificial Acacia hybrid, obtained by full-diallel control crossing. Observed sample trees were clones at the clonal test, established in 2011 in Wonogiri, Central Java. Tree samples were taken by selecting clones categorized into the superior, intermediate, and inferior clones based on their growth at one year of age, with three different clones in each category. Parameters to be observed were morphological characters including quantitative (tree height, diameter breast height, bole length, phyllode length and phyllode width) and qualitative (stem form, stem straightness, bark type, bark color, phyllode shape, phyllode apex shape, conspicuousness of the main vein, and petiole color). The data quantitative and qualitative were then scored and analyzed using NCSS series 12 software for cluster analysis. The results showed that morphological characters of Acacia hybrid clones varied across the tree categories. Furthermore, the dendrogram showed that the characters of Acacia hybrid grouped into two clusters: Cluster A dominated by superior and most intermediate clones, and Cluster B dominated by inferior clones. The study result implies the use of morphological characters of Acacia hybrid to select the hybrid vigor in a breeding program.