MATERIAL AND METHOD 1 Material

Bogor, 21-22 October 2015 813 higher the genetic diversity, the more variation there is for selection and improvement of desirable traits Lee et al.2000. A selection activity in forest tree breeding programs will be narrowing the genetic variation. Therefore, genetic conservation needs to be done to conserve variation of the genetic resources for future breeding programs. Forest Research Institute of Kupang has established an ex situ conservation plot of sandalwood from western part of Timor Island population which was intended for base population of sandalwood breeding program. The plot was planted in a separate area to prevent genetic contamination among populations so that population differentiation is maintained. Identity of each seedling of each mother tree family, was planted in a single tree plot to give more benefit and minimize inbreeding as each tree is surrounded by different families. This study was aimed to investigate the influence of genetic factors on the growth characteristics of sandalwood at the age of 8 months after planting in the ex situ conservation plot. The information is essential for implementing proper breeding strategy. 2. MATERIAL AND METHOD 2.1 Material The ex situ conservation plot was located in Banamlaat, Kefamenanu, Timor Tengah Utara district, Nusa Tenggara Timur province and was managed by the Forest Research Institute of Kupang. The trees were 8 months of age after planting. The ex situ conservation plot was laid out in an Incomplete Block Design IBD comprised of 25 families, single tree-plot and 10 replications. Trees were planted at 4 × 4 m spacing. 2.2 Data collection Assessments of growth parameters were undertaken in July 2013. The parameters measured were survival rate to assess field adaptation, and total height and diameter to assess growth performance. Plot survival rate was the ratio of the number of surviving trees with those planted. All surviving trees in the trial were assessed for tree height and diameter. Total height m was measured from the ground to the top of the tree, and stem diameter at 5 cm aboveground. 2.3 Data analysis 2.3.1 Adaptability One of the most important results of a progeny test is adaptability. Adaptations are special features that allow a plant to live in a particular place or habitat. The adaptability of a plant can be determined by its ability to survive in a certain environment Hawtin et al.,1997. Plant adaptation was determined by evaluating the survival rates of the trees in the trial. The survival rate was measured by dividing number of survived trees with the number of originally planted trees in the tree plots and multiplied by 100. 2.3.2 Variation in height and diameter Variation in individual data of tree growth performances were analysed using the Analysis of Variance. The following linear model was used O’Neill, 2010; Yudohartono, 2013: Y ijk = μ + B i + F j + BF ij + E ijk ...................................... 1 Where: Yijk : individual observation ofkth tree in the block ith and the jthfamily; : overall mean; Bi : effect of the ith block; Bogor, 21-22 October 2015 814 Fj : effect of the jthfamily; BFij : interaction effect of the ithblock and the jthfamily; Eijk : residual 2.3.3 Heritability Genetic parameters were estimated by calculating the heritability values and genetic correlation between traits. Heritability is the proportion of the genetic factors of interest that is inherited from parent to offspring Zobel Talbert, 1984.In other words, heritability is the statistical expression for the relative contributions of genotype and environment to the phenotype performance, and is useful in predicting gain from selection. Individual h 2 i and a family h 2 f heritabilities were calculated from the following equations Zobel Talbert, 1984: .............................................................................. 2 .............................................................................. 3 Where: σ 2 f : variance component of family; σ 2 fb : variance component of family and block interaction; σ 2 e : variance component of error; n : harmonic mean of trees per plot sum; b : harmonic mean of blocks sum. 3. RESULT AND DISCUSSION 3.1 Adaptability