Bogor, 21-22 October 2015
536 abundant coppice, have high quality wood for energy and provide multi-purpose functions.
Calliandra calothyrsus which has that criteria, grows very fast to 2.5 - 3.5 m within 6 months and to 3-5 m within the first year, with first harvesting achieving to 5-20 m3ha of fuelwood in
Java’s fertile soil. Its annual coppicing that can be harvested up to 10-20 years, is complemented with its high wood density BJ 0,51-0,78 and high wood 4,500-4,750 calg
and charcoal 7.150- calg calorific values NAS 1980, Syachri 1983 which make it a favorite species for wood energy purpose and for climate change mitigation by providing soil cover,
increasing soil fertility, and long period of carbon capture. Communities in Indonesia especially Java, have been using Calliandra calothyrsus for fuelwood Hendrati et. al., 2011. This
species able to grow within a wide range of elevation 100-1800m asl, produce leaves for green manure, fix nitrogen, prevent soil erossion and protect soil water, is an ideal species to
choose for breeding to produce genetically improved individuals for wood energy including wood pellet.
Demands of Calliandra seeds to support wood pellet industries has been growing considerably in Indonesia following export loads for wood pellet requested by many
developed countries. Korea targets to get import of 5 million ton wood pellet in 2020 to realize 75 of their country needs. This has been initiated with establishment of pellet
industries in Asean Countries including Indonesia Java with 4.6 folds production just within 4 years 2009-2013 pers. Comm Mr. Park, 2013. The booming of wood pellet markets in
Europe was also driven by the EU 2020 policy targeting a decline of greenhouse gas GHG emissions and 20 renewable energy supply by 2020 Rakos, 2008. European industrial pellet
markets currently depend on wood pellets imports and by 2020, their needs for woody biomass are predicted in the range of 105-305 million tonnes Sikkema, 2011. North America
pellet industries which are escalating rapidly are also experiencing regular shortages, instable price and quality Spelter and Toth, 2009. This situation has been attracting so many stake
holders in Indonesia to establish plantations and wood pellet industries since 2013. In fulfilling this, government institutions and private companies from many provinces including North
and South Sumatera, West and East Java, DIY, Bali and Nusa Tenggara, East and Central Kalimantan, South Sulawesi and West Papua have been requiring Calliandra seeds for
establishing wood energy plantations. Genetic improvement of Calliandra calothyrsus is therefore worth to carry out. This paper
discuss results of its genetic improvement that has been conducted to obtain best individuals with outstanding productivity and quality.
2. MATERIAL AND METHOD
First generation F1 progeny test of Calliandra calothyrsus was established in 2010, from 10 out of 14 populations collected from Indonesia. The overall 10 population with a number of 120
families were selected Figure 1 and Table 1 based on sound seeds availability, germination rate and seedlings availability for trial, distance between populations and variation of elevation.
The trial was set with 120 families x 4 trees x 5 blocks x 3X2m spacing in Wonogiri, Central Java at area with 1878mmyear precipitation, elevation of 141 m asl and minimum-maximum
temperatures of 21.21-38.2
◦
C. Growth data were collected at 4, 16, and 30 months. Selection based on growth height,
diameter, bole length, number of branches and volume were carried out by felling 1 tree for each family plot based on growth data measured before. At the end, sample disks were also
taken from cut individuals from 4 blocks for lignin content and calorific value analysis. Lignin contents were measured by using Chesson-Datta method 1981 corrected by ash content.
Bogor, 21-22 October 2015
537 Calorific values were assessed by using Bomb Calory Meter according to ASTM D 2015. A
1x1x1 cm cube was taken for calorific value and 2-gram grounded sample of each disk was taken for lignin content analyses.
Analysis of variance was undertaken using individual tree data for growth using the linear model Y
ijk
= + R
i
+ F
j
+ RF
ij
+ε
ijk
where Y
ijk
is the k-th individual tree data of the j-th family in the i-th replication;
is the overall mean, R
i,
F
j,
RF
ij,
and ε
ij k
are respectively, the i-th replication effect, the j-th family effect, the interaction effect of the j-th family in the i-th
replication, and the within family-plot error for Y
ijk.
Figure 1: Population sources of Calliandra genetic materials in Indonesia used for breeding Appropriate variance components for genetic parameters were estimated from the sums of
squares and then comparing it with their expected values. The individual tree heritability h
i 2
was calculated using the following formula h
i 2
= σ
2 f
0.3 [ σ
2 p
] Williams et al., 2002, where σ
2 f
and σ
2 p
are estimates of the variance component for family and total variance component respectively. The predicted genetic gain by direct selection was calculated using the following
formula ∆g
d
= i
y
.h
y 2
. σ
Py
Falconer and Mackay 1996. Mean annual increment was estimated from selected individuals if planted per hectare divided by its rotation.
Table 1: No of families of each Calliandra population in Indonesia used for breeding No. Provenance
Number of families Elevation m asl
1 Majalengka, West Java
9 1070-1211
2 Sukabumi, West Java
9 1026-1040
3 Grabag, Magelang, Central
java 17
912-1033 4
Tretes, East Java 8
907-1015 5
Pujon, Malang, East java 9
1270-1450 6
Lahat, South Sumatera 10
610-697 7
Aek Na uli, North Sumatera 13
919-1413 8
Makale, South Sulawesi 16
589-1040 9
Soe, East Nusa Tenggara 15
708-1291 10
Wamena, Papua 14
1680-1759 3. RESULT AND DISCUSSION
3.1 Variation between populations
Variation among 10 populations used for setting the progeny test were present at 16 months for all traits, but becoming trivial after 30 months, except for volume Table 2. High disparity
within each population would influence these similarities. Selection based on population is therefore not recommended for Calliandra at population level, because lack of variation will
Bogor, 21-22 October 2015
538 cause meaningless screening. Consequently, selection with higher resolution, such as at family
level or even at individual level, is required to obtain higher gain. Table 2: Variations of Calliandra traits among different population sources at 16 and 30
months
Trait Differences among populations
months 16
30
Height Ns
Diameter Ns
Bole length Ns
Number of branches Ns
Volume m3tree 0.001950 -0.003375
Flowering Ns
Study of Calliandra genetic diversity from 10 populations used in this study reveals that although Calliandra in Indonesia was originally estimated from limited sources, however there
are moderate genetic diversity within population land race and moderate genetic distance among populations Pers. Comm. Nurtjahyaningsih, 2015 which should be appropriate for
breeding. For advanced breeding however, infusion of genetic materials, especially from its natural habitat in South America need to be considered to broaden more of its diversity.
Calliandra is not native to Indonesia and brought to Indonesia in 1936 Chamberlain, 2001. It has been grown abundantly throughout Indonesia since then by bringing more provenances
from its original habitat in Central America Jim Roshetko, ICRAF, pers. Comm 2012. Calliandra bear flower at less than 1 year and is able to produce seeds starting from the second
year, in which within the next 2-4 years, new generation may emerge. Since 1936 up to now 2015, Calliandra may have been developing to nearly 20 generations at particular sites and
forming land races. These established generation cycles would only be created from genotypes that can adapt well to their new environment. Therefore, there were very high possibilities that
they might have formed distinct differentiations and variations and possibly mutations among different locations in Indonesia within different environment and elevation of each
population. These created variations will be precious for its breeding. Land races are valuable genetic materials for breeding because variations created from site differentiations will make
breeder able to carry out selection for particular trait. Land race is created when species has been able to adapt better to particular environment causing small amount of genetic
improvement by natural or silvicultural selections than the seeds which were initially introduced Eldridge et al., 1993. Selections might bias allele frequency especially those loci
under selection or which linked to adaptive genes Lowe et al., 004. Taking into account of its history with high likelihood of differentiation since its long time introduction and also
considering evidences that there were limited variations of growth among population, variation at family level need to be examined.
3.2 Growth characters for productivity
Significant variations that generate high heritability values would determine the selection success by obtaining high genetic gain Zobel and Talbert, 1984. Unlike limited variation
among Calliandra populations, variations of traits among families in Calliandra have been found to be significant in all characters at 16 months, which indicate a very good promise to
undertake selection. However, numbers of branches and bole length as characters assumed to influence volume, they were found to have no significant variation after 30 months.
Bogor, 21-22 October 2015
539 Fortunately growth characters, height and diameter, that greatly influence volume or
productivity are significantly varied Table 3 which is worth further examination. Table 3: Variations between families in Calliandra calothyrsus characters at 4, 16 and 30 months
Character Months
4 16
30
Height m 0.4-1.3
1.3-3.6 3.09-5.2
Diameter cm 0.5-1.2
1.1-4.2 2.3-7.6
Bole length cm 0.1-7.1
20-106 ns
No. of branches Na
1.8-3.1 ns
Volume m3tree
0.000005- 0.000012
0.001139- 0.002485
0.003-0.008066 Flowering
0-0.4 0-0.9
0-1 In this breeding, selection for Calliandra is directed to be at individual level rather than at
family level. Calliandra can be easily propagated vegetatively, which gives more advantages to select at individual level so that clonal materials can be obtained from multiplication of the
selected individuals. This could produce new clonal plants which are genetically identical to the genetically improved ortet parent and will provide much better genetic gain than by using
seedling Shelbourne et al., 2007. Selection at individual level is also beneficial to avoid possible variations that may occur within families which are generated from seeds of the same
female parent but fertilized by different unknown male parents. Variations in breeding will only be meaningful, when high individual heritability values h
2
are produced. Heritability values describing the degree to which genetics influences the trait. The
narrow sense heritability h
2
, is a measure of the predictability of offspring trait values that are based on parental trait values. Individual heritability values of 0.3, are classified as high
Cotterill and Dean, 1990. In this study, the results produced high individual heritability values for three growth characters which are volume h
2
=0.5, height h
2
=0.38 and diameter h
2
=0.34. Volume which possesses the highest heritability value will become one excellent character for selection when optimum improvement in productivity from this breeding
process is expected. Compared to volume, height and diameter can be less overlooked because they have been incorporated when calculating the value of volume. Therefore volume is the
character to represent more on productivity, and in this study it should be used as the first criteria for selection.
3.3 Approaching Characters for Wood Energy Quality
In term of quality for wood energy, especially wood pellet, high lignin content is required to enhance high heating value. Lignin, brown amorphous crystal insoluble in water and most
organic solutes Robinson, 1991, has thermoplastic characters. It melts under high heating point and re-solidify under cold temperature, and this character is useful for producing high
quality glue, produced based-on lignin Tsoumis, 1991. Therefore, this would reduce or even remove the cost of expenses for additional binding materials in the production of wood pellet
for wood energy. Lignin content has also been known to have high positive correlation with heat of combustion White, 1987 and so increasing calorific value. It has stable and stiff
characters that hinder water penetration Evert, 2006 to make wood pellet relatively dry and less weighty and repel high possibility of pest and disease attack. Lignin stabilizes wood
dimension Panshin dan deZeeuw, 1980, and therefore it makes wood pellet sturdy and not easily broken.
Bogor, 21-22 October 2015
540 In selecting individuals for wood pellet, besides considering outstanding productivity
volume, it is also important to concern about wood energy quality, represented by lignin content and calorific values. However, laboratories works for analyzing lignin those two
quality characters are time and cost consuming and both require skilled personnel. Therefore, whenever possible, wood energy quality should be approached by relatively easy, cheap and
fast characters to measure. There have been essential results indicated in this study that quality characters can be approached by diameter. Diameter which is easy, cheap and fast trait to
assess is found to have significant positive correlations with lignin content R
2
= 0.137, R =0.4, Y = 2.469X + 20.867 and even more with calorific value R
2
= 0.38, R=0.62, Y =100.57X + 3847.3. These correlations exist for individuals with diameter of 3.5cm.
However to ensure more of the calorific value, branch thinning to obtain 3-5 big diameter 5cm is suggested. Individuals with high lignin content and consequently calorific value are
therefore expected from those that have higher diameter to obtain quality wood energy. The laboratory assessment for lignin content of selected Calliandra individuals indicate that their
average lignin content at young age 24 months is 33 which is classified as high according to Supartini 2009. Diameter which is highly related to quality characters is therefore should
be decided to be the second criteria for selection after volume.
3.4 Base-line selection using quantitative and qualitative characters
Results of main characters for both productivity and quality are used for undertaking base-line selection. Through the measurement, volume has shown to have incredibly high individual
heritability value and therefore worthy to be used as the first productivity criteria for selection. While in term of quality, it turns that the values of lignin contents and calorific values analyzed
in the laboratories are significantly related to branch diameter at the size suitable for fuel 3cm, meaning that diameter need to be used as the second criteria for selection in this
particular trial. By using based-line selection with volume quantity and diameter approached for quality, selection of for best individuals have found 58 best individuals out of final
individuals 600 after experienced 3 consecutive selection in advance for growth from initial grown plants 2400 based on index selection.
By using selected individuals, it is estimated that the MAI of Calliandra will reaching up to 65m3hayear at 1x0.5m spacing starting from 2,5 years old, but it is likely to increase with
time with proper silviculture. Calliandra first harvest was recorded achieving fuelwood of 5- 20 m3ha i
n Java’s fertile soil NAS, 1980; Syachri, 1983, although it may produce 35- 65m3hayr after growing 10-20 years. This breeding result is also much higher compared to
short rotation wood energy such as willow Salix sp. in western Europe that produce around 11.700 kghayr or around 17m3hayr Vandenhove et. al., 2004 or short-rotation forestry
hybrid, aspen Populus tremula L. x P. tremuloides Michx. that produce around 14m3hayr at 4 year rotation Tullus et. al., 2011. Compared to plants growing in countries having 4 seasons,
this outstanding growth might also because of longer optimum growth environment that are available in tropical countries including Indonesia where sunshine are abundant along the year
with long rainy season and with only a slight fluctuation of temperature between dry and wet season.
In term of best selected individuals among the tested trees, a number of 58 individuals comprising of 41 families that have been selected are expected to provide appropriate genetic
diversity. This should avoid narrowing diversity of population productions and so hindering vulnerability from pest and diseases attack. A number of 58 individuals is also said to be
sufficient ≥ 50 families to conserve genetic variation Lowe et al., 2004 while 25 families
Bogor, 21-22 October 2015
541 need to be available because seed sources established with ≥25 families will be eligible to
obtain legal certification in Indonesia P 72Menhut-II2009. The results show that the highest proportion of best families are those from Tretes, Lahat,
Majalengka, Makale and Grabag which each population has 41 families with selected individuals. Further, the biggest genetic diversity within population is shown from within
Grabag, Magelang population 0.4 Pers. Comm. Nurtjahyaningsih 2015. Interestingly, there has been no family perform outstanding from Wamena population, which was originated from
the highest elevation. This might be caused by difficulty of its genotypes to adapt to low altitude.
3.5 Possibility for cloning
There have been great promises to propagate vegetatively of genetically improved Calliandra individuals. Production of mother plants by using air layering from genetically improved
individuals, produce roots at 1-1,5 months and after 1 month of climatic adjustment, new genetically improved individuals can be produced for further deployment. Producing clonal
materials by using cutting is in progress, while propagation using higher technology, tissue culture, has been able to produce roots from plantlets only after 2 months Pers. Comm.
Ardhany, 2015 which is very promising for mass scale production. With genetically improved individuals available from suitable species for wood energy that can
be harvested from its coppice in the second year like Calliandra and with advantageous environment, Indonesia need to make every effort on using renewable energy from wood
biomass. This can only be achieved by working together hand in hand between government and possible stakeholders including farmers to catch the opportunity in taking part on
fulfilling current and future global demands by using genetically improved Calliandra resulted from the breeding process.
4. CONCLUSION
