| dc.description.abstract | Indonesia is the 9th largest pulp producer in the world and is able to supply
the world's pulp needs of 3 percent of the world's total capacity. The wood of
Eucalyptus grandis used as a raw material for charcoal, firewood, pulp products
from wood fiber and wood-working. The increment of wood supply is
determinant as guarantee this pulp production and it’s supported by the
improvement of genetic materials. In tree improvement activities, estimation of
genetic parameters for several traits needs to be carried out before selection
activities due the phenotype of a plant is determined by genetic and environmental
factors. Plant growth and productivity, wood basic density and pulp yield are
important traits to know in order to determine the efficiency of using raw
materials in producing pulp. For estimating the wood properties, it requires nondestructive testing to keep the plant growing like its original population. Pulp
yield character can be estimated by using an NIR (Near Infrared), while the wood
basic density traits can be estimated using a resistograph which calculates the
amount of resistance when drilling wood from the bark to the bark of the wood.
For wood properties evaluation, preciously modelling is necessary.
A population of E. grandis at North Sumatera, Indonesia at 1800 m altitude
was analysed for growth and wood properties in this work. Pulp yield (PY) traits
were assessed using microNIR and wood basic density (BD) traits using
resistoraph. Wood basic density modelling using resistograph was carried out with
315 trees consisting of 158, 139, and 18 trees of Eucalyptus grandis, E. urophylla,
and eucalyptus hybrid urograndis. Pulp yield prediction data were analysed with
the model developed by PT. Riau Andalan Pulp and Paper Wood Technology
Department using microNIR. Wood basic density modelling was analysed with
linear regression analysis. Variability and genetic parameter analysis for E.
grandis population were carried out with restricted maximum likelihood (REML)
and the retraction of genotypes was used best linear unbiased prediction (BLUP)
analysis with different selection simulations.
The result from wood basic density modelling showed that basic density
traits had a variability inside the tree, intra-, and interspecific species. There were
found the whole tree’s basic wood density of 379.9 kg/m3
, 400.5 kg/m3
, and 440.6
kg/m3
at 44 months old for E. grandis, hybrid urograndis, and E. urophylla,
respectively. The model developed had a good correlation for predicting wood
basic density at 1.3 m and whole tree basic density with the coefficient of
determination (R2
) were in a range of 0.56 to 0.74 for 1.3 m wood basic density
prediction, 0.66 to 0.79 to predict whole tree wood basic density and 0.65 to 0.76
to predict average wood basic density. Combined data from all species shows the
best model with R2
0.74 to 0.79. After modelling the assessment for wood basic
density using resistograph and pulp yield using the microNIR was carried out.
The variability analysis for growth character showed individual heritability
for growth character with Height (HT) and diameter breast height (DBH) traits
was 043 and 0.36, for wood properties character (BD and PY) were 0.41 and 0.39.
The family level of heritability for growth character (HT and DBH) were 0.86 and
0.87, and for wood properties character (BD and PY) were 0.87 and 0.77. There
were found positive and negative significant genetic and phenotypic correlations
between traits. Individual selection shows a slight variation using different
selection methods between mass, best linear unbiased prediction (BLUP), and
block selection. BLUP selection gives the middle gain and the lowest number of
effectiveness (Ne). The family selection gives the lowest gain and the lowest Ne.
The selection based on individual performance as BLUP, mass, and block
selection showed better results in genetic gain and number of effective size (Ne)
compared to family level selection. | id |
