Ministry of Agriculture & Rural Development Collaboration for Agriculture and Rural Development Strengthening Capacity in Forest Tree Seed Technologies Serving Research and Development Activities and ex-situ Conservation (No. 058/04VIE) GENETIC IMPROVEMENT PLAN FOR EUCALYPTS IN VIETNAM by Khongsak Pinyopusarerk 1 , Le Dinh Kha 2 and Chris Harwood 1 Ensis Genetics, PO Box E4008, Kingston, ACT 2604, Australia 2 Research Centre for Forest Tree Improvement, Forest Science Institute of Vietnam, Hanoi, Vietnam 3 Ensis Tasmania, Private Bag 12, Hobart TAS 7001, Australia December 2006 1 TABLE OF CONTENTS GENETIC IMPROVEMENT PLAN FOR 1 EUCALYPTS IN VIETNAM 1 EXECUTIVE SUMMARY 4 1 Introduction and Background 6 1.1 Species-Provenance Trial in the Lowlands of Central Vietnam 6 1.2 Species-Provenance Trials in the Southern Highlands 8 1.3 Current Eucalypt Species in Reforestation Programs 8 2 Genetic Improvement of Eucalyptus species in Vietnam 9 2.1 Candidate Plus Tree Selection and Clonal Testing 9 2.2 Development of Eucalypt Hybrids 9 2.3 Open Pollinated Progeny Trials Developed into Seedling Seed Orchards 10 2.4 The Need for a Genetic Improvement Strategy and Plan 10 3 Basic Elements of Planning Tree Improvement 11 3.1 Need for a Well Defined Strategy and Plan 11 3.2 Clear Objectives 11 3.4 Selection and Mating 12 3.5 Personnel and Funding 13 3.6 Hybrid breeding 13 4. Determinants of a Breeding Strategy 15 4.1 Breeding Objective 15 4.2 Economic Weights 15 4.3 Deployment Objective 15 4.4 Selection Criteria and Traits for Selection 16 4.5 Genetic Resources 16 5 Breeding Strategy 20 5.1 Outline of Breeding Strategy 20 5.2 Expected Genetic Gains 21 5.3 Breeding Population 22 5.3.1 Structure of the Main Population 22 5.3.2 Structure of the Elite Population 22 6 Outlines of Improvement Plan 23 6.1 Eucalyptus urophylla 23 6.1.1 Main breeding population and seedling seed orchard 23 6.1.2 Elite population and clone bank/clonal seed orchard 23 6.1.3 Selection of candidate trees for the second generation 28 6.1.4 Conversion of trials to seed orchards 29 6.2 Eucalyptus pellita 29 6.2.1 Main breeding population and seedling seed orchard (optional) 30 6.2.2 Elite population and clone bank/clonal seed orchard 30 6.2.3 Selection of candidate trees for the second generation 32 6.2.4 Conversion of trials to seed orchards 33 6.3.1 Main breeding population and seedling seed orchard 34 6.3.2 Elite population and clone bank/clonal seed orchard (optional) 34 6.3.3 Selection of candidate trees for the second generation 36 6.2.4 Conversion of trials to seed orchard 36 6.4 Eucalyptus grandis 37 6.4.1 Main breeding population and seedling seed orchard 37 6.4.2 Elite population and clone bank/clonal seed orchard (optional) 37 6.4.3 Selection of candidate trees for the second generation 39 2 6.4.4 Conversion of trials to seed orchard 39 6.5 Eucalyptus camaldulensis 40 6.5.1 Main breeding population and seedling seed orchard 40 6.5.2 Cloning of the progeny trial 40 6.5.3 Establishment of clonal trials 41 6.5.4 Conversion to clonal seed orchard 41 7 Program Review 42 References 43 3 EXECUTIVE SUMMARY The Government of Vietnam (GoV) has embarked on a massive tree plantation program. By 2010 it plans to establish an additional 5 million hectares of plantations on bare hills and degraded forest lands, over and above the current plantation estate of one million ha, plus the equivalent of more than 50,000 hectares of community forests in scattered plantings. This dramatic expansion requires equally dramatic increases in the amounts of genetically- superior seed suitable for the different ecological zones in Vietnam. The GoV is committed to improving the amounts and qualities of tree seed produced from its own seed orchards, which is a more sustainable strategy than depending on imported seed. Exotic species such as acacias and eucalypts are important species included in the planting programs. In order to enhance the productivity of the plantations in Vietnam, genetic improvement programs have been carried out for many tree species mainly by the Research Centre for Forest Tree Improvement of the Forest Science Institute of Vietnam. However, these works have been conducted without a written plan that follows a clearly defined genetic improvement strategy. As part of AusAID-supported CARD project (No. 058/04VIE) “Strengthening Capacity in Forest Tree Seed Technologies Serving Research and Development Activities and ex-situ Conservation” a genetic improvement plan has been developed focusing on priority Eucalyptus species. A separate CARD project (No. 032/05VIE) “Sustainable and profitable development of acacia plantations for sawlog production in Vietnam” will soon develop a genetic improvement plan for acacias. It should also be stressed that the approaches discussed in this breeding strategy are applicable for most tree species. Breeding populations of five Eucalyptus species (E. camaldulensis, E. grandis, E. pellita, E. tereticornis and E. urophylla) already set up by the Research Centre for Forest Tree Improvement provide the basis for genetic improvement framework being addressed by this improvement plan. However, greater effort and input are put into E. urophylla as the highest priority Eucalyptus species for pure and interspecific hybrid breeding. Other species have been managed less extensively with an aim to use them as pollen sources for interspecific hybridisation. The proposed breeding strategy is based on a structured breeding population that is divided into two levels based on genetic quality. That is the breeding population is subdivided into two parts, a ‘Main (large) Population’ and an ‘Elite (small) Population’. The populations have several distinct functions in the breeding program, and a large part of the breeding strategy in each generation deals with the plan that specifies the selection, breeding and management of these two components of the breeding populations. As interspecific hybridisation is receiving increasing interest, the ‘Elite Population’ is the source of genetic material used for interspecific hybrid crossing, in addition to it being one of the sources of pure-species clones for operation deployment. Therefore, the strategy places maximum emphasis on this population to ensure maximum genetic progress. The ‘Main Population’ provides for gene conservation and long-term, sustained genetic progress, by providing new selection to the ‘Elite Population’ each generation. For the ‘Main Population’ there is only a single type of genetic test (open-pollinated progeny test) for each generation. The families and individual trees within families are ranked using the test data, and selection are made to move up to enrich the gene pool of the ‘Elite 4 Population’ and to regenerate the next generation’s Main Population. The overall strategy in the Main Population can be defined as recurrent selection for general combining ability. A greater emphasis is placed on the breeding, testing and selection of the Elite Population each generation, because the clones derived from the Elite Population serve as the clones for use in operational plantations and for intra- and interspecific hybridisation. Controlled crosses are made between selections of the same species and of other species. Vegetative propagation of the progeny and clonal testing is used for forward selection of the best clones for operational use. The very top ranking clones only are used for interspecific hybridisation. A time plan for operation is provided for each species. It should be treated as a general guide only. A more detailed work program providing month-by-month activity schedules should be prepared by the Research Centre for Forest Tree Improvement taking into consideration both administrative possibilities and technical limitations. It is common for every genetic improvement plan to be reviewed and may be revised after some period of operation. This genetic improvement plan is no exception and should be subject to an independent review after 2 years into the program. 5 1 Introduction and Background Eucalypts are one of the most important groups of plantation species for the supply of industrial raw materials in Vietnam. Their wood is used for pulp and paper, particleboard, construction and furniture. There are substantial block plantations of eucalypts in many parts of Vietnam. They are widely planted along canal banks in the Mekong Delta, and along dams, rice paddy boundaries and roadsides and as wind breaks in the Red River Delta. They are also widely planted in many places throughout the country as scattered trees. Moreover, eucalypts provide much of the fuel wood for most of rural areas of Vietnam. Together with acacias, eucalypts have significantly contributed to the improvement of income and living standards of rural people in lowland areas, particularly in central and central-northern Vietnam. The area of eucalypt plantations Vietnam at the end of 2001 was estimated as 348 000 ha (Le Dinh Kha et al. 2003a). The current planted area is believed to be around 500,000 ha. This figure does not include millions of row plantings and scattered trees equivalent to 50,000 ha in routine plantation form. Eucalypts have been introduced into Vietnam since 1930. Eucalyptus camaldulensis and E. robusta were the first Eucalyptus species introduced into Vietnam in 1930 by the French. More species were introduced during 1950-1958 in Da Lat (central highlands), and among these E. microcorys was found to be very promising. In 1960 E. exserta was introduced and became an important species for re-greening bare land and denuded hills. Up to 50,000 ha of E. exserta plantations were planted during the 1960s. However, the popularity of E. exserta has since declined because of its slower growth rate than other species. It was not until the 1980s that systematic species and provenance trials were established at different ecological zones of Vietnam. However, lack of comprehensive representations of provenances in some species in those early trials led to premature conclusions. An example was the case of the Petford provenance of Eucalyptus camaldulensis which was identified as an outstanding seed source in the early 1990s (FSIV 1990, Hoang Chuong 1992). Results of later species-provenance trials revealed that growth of Petford provenance was only mid- ranked and it was very susceptible to die back diseases in the south-eastern part of Vietnam and Thua Thien Hue (Sharma 1994, Pham Quang Thu 1999). The most promising provenances of E. camaldulensis in Vietnam are Laura River, Kennedy River and Morehead River (northern Queensland) and Katherine (Northern Territory) (Le Dinh Kha and Doan Thi Bich 1991) while the best provenance of E. tereticornis tested during the 1990s was Sirinumu Sogeri (Papua New Guinea) (Hoang Chuong 1996). 1.1 Species-Provenance Trial in the Lowlands of Central Vietnam Provenance seedlots of six species were planted at Dong Ha, Quang Tri province in 1991 (Table 1). Eight-year growth data show that many provenances of E. cloeziana (e.g. Queensland provenances of Herberton, Helenvale, Woondum and Cardwell), E. pellita (Queensland provenances of Kuranda and Helenvale) and E. urophylla (Indonesian provenance of Lembata) performed well above overall trial mean. In general, E. camaldulensis, E. grandis and E. tereticornis were slower in growth rate than the other three species with most provenances ranking below the overall trial mean. However, it should be noted that some of the best performing provenances of E. camaldulensis (i.e. Laura River, Kennedy River and Morehead River) were not included in this trial and E. grandis was not suitable for low land areas (Le Dinh Kha et al. 2003b). 6 Table 1. Growth of eucalypt species and provenances tested at Dong Ha (Quang Tri province) (1/1991-7/1999). Seedlot Species/provenance DBH (cm) H (m) x v (%) x v (%) 23645 E. urophylla Mt Lembata, Indonesia 11.4 19.3 13.2 15.9 23081 Mt Egon Ind. 9.3 21.8 10.7 9.1 23042 Mt Lewotobi Ind. 9.0 23.2 10.5 18.3 Mean 9.9 21.4 11.5 14.4 14236 E. cloeziana Herberton Qld 10.5 20.1 12.7 17.9 12602 Helenvale Qld 10.3 15.2 11.6 13.3 17008 Woondum Qld 10.3 23.2 11.6 14.3 14422 Cardwell Qld 10.3 20.5 11.3 20.4 12205 Maitland Qld 10.1 17.7 11.0 15.2 12202 Paluma Qld 10.0 17.2 11.0 11.6 13543 Monto Qld 9.6 21.9 10.9 15.3 12207 Bakerville Qld 9.6 20.6 10.8 10.6 14427 Blackdown Qld 9.5 17.7 10.7 9.0 Mean 10.0 19.3 11.3 14.2 15255 E. pellita Kuranda Qld 10.2 18.6 11.3 12.6 14211 Helenvale Qld 10.2 16.8 11.1 14.9 16122 Kiriwo PNG 10.1 20.6 11.0 17.4 13998 Coen Qld 9.7 17.6 10.9 12.6 16120 Keru PNG 8.9 25.2 10.2 17.0 13826 Bloomfield Qld 8.4 22.1 9.8 17.2 Mean 10.1 18.6 11.1 14.3 13661 E. tereticornis Mt Molloy Qld 8.9 20.1 10.2 17.6 13660 Helenvale Qld 8.8 21.4 10.2 18.6 13666 Mt Garnet Qld 8.4 19.7 10.0 17.7 Mean 8.7 20.4 10.1 18.0 13289 E. grandis Mt Lewis Qld 8.8 18.5 10.1 9.7 16583 Atherton Qld 8.0 22.7 9.1 16.8 16723 Paluma Qld 7.9 23.1 8.8 25.6 14838 Cardwell Qld 7.5 23.5 8.7 21.2 Mean 8.1 21.9 9.2 18.3 16720 E. camaldulensis Petford Qld 8.2 21.9 9.5 17.0 13695 Normanton Qld 8.0 22.9 9.1 17.5 Nghia Binh VN 7.8 27.2 8.7 16.5 15049 Bullock Creek Qld 7.2 22.2 8.6 18.3 16553 Wrotham Qld 6.4 26.1 7.6 15.9 12968 Buderkin River Qld 6.2 21.8 7.4 20.2 15325 Camooweal Qld 6.1 23.1 7.4 17.0 15323 Julia Creek Qld 5.9 18.2 7.2 15.9 13817 Leichhardt R Qld 5.5 22.3 6.6 16.8 Mean 6.8 22.9 8.0 17.2 Fpr <.001 Fpr <.001 S.e.d = 0.933 S.e.d = 1.153 7 1.2 Species-Provenance Trials in the Southern Highlands Twenty four provenances of 9 Eucalyptus species were tested in Da Lat at Lang Hanh (altitude 900 m) and Mang Linh (altitude 1500 m) in 1992. Available growth data at 18 months of age at Mang Linh shows that the fastest growing provenance was E. urophylla, Mt Egon, Flores, Indonesia. It was followed by E. grandis Lam Dong land race and Paluma, Qld, and E. saligna Blackdown and Barrington, Qld. E. camaldulensis from GibbRiver, Katherine and Morehead River also grew well. Slower growing provenances were E. brassiana Jackey Jackey, Qld; E. camaldulensis Emu Creek Petford, Qld; E. tereticornis Mt Garnet, Qld; E. grandis Mt Lewis and Tinaroo, Qld. All E. pellita provenances grew slower than overall trial mean. The high altitude of 1500 m appeared to be too high for many Eucalyptus species such as E. brassiana, E. camaldulensis, E. pellita and E. tereticornis. No further detailed information from these 1992 trials was available except a brief reference in Le Dinh Kha et al (2003a) that some 11-year-old trees of Da Lat land races of E. saligna and E. microcorys were growing well at Lang Hanh, mean height 25.1 and 22.5 m respectively. Based on the results of past species and provenance trials, many species are considered promising for planting in different regions of Vietnam: Lowlands, central to southern provinces: E. brassiana, E. camaldulensis, E. cloeziana, E. exserta, E. pellita, E. tereticornis, E. urophylla Lowlands, northern provinces: E. exserta, E. pellita, E. urophylla (on deeper soils (canal banks, roadsides etc) E. camaldulensis is an excellent performer and widely planted in the north, although it is no good on the shallow hillside soils. I don’t know that there is much evidence that E. pellita is good in the north (it may be). You probably need a paragraph describing the different types of planting sites available – small planting areas on flat land with deep soil, and much larger areas (bare hill type site) of sloping land with generally rocky shallow soil especially in north and central-north. In the south and parts of the central highlands there are larger areas of better soil and reasonably level ground although these are mostly being planted to acacia hybrid now. The species rankings and performance of hybrids change according to these soil types. Central highlands: E. grandis, E. microcorys, E. saligna,E. urophylla and E. pellita can also be planted up to altitudes of around 900 m asl in the Central Highlands. 1.3 Current Eucalypt Species in Reforestation Programs Vietnam has embarked on a massive tree planting program as part of the national 5-million hectare Reforestation Program (2000-2010). In general, the type of planting sites available for tree planting differs between regions. In the north and central north, there are small areas on flat land with deep soil, and much larger areas (bare hill type site) of sloping land with generally rocky shallow soil. In the south and parts of the Central Highlands there are large areas of better soil and reasonably level ground although these are now mostly being planted to acacia hybrid. Although many Eucalyptus species have been found suitable for planting in Vietnam, only a few are currently being propagated and planted. The most widely planted species are E. urophylla and its interspecific hybrids. Planted area of these species now exceeds 200,000 ha. The other main species, E. camaldulensis and E. tereticornis, are mainly planted in the south. 8 There are also quite large plantings of E. camaldulensis and E. tereticornis in central Vietnam e.g. in Hue province but these seem to be being progressively replaced with acacia hybrid plantations. The total annual planting in Vietnam is about 200,000 ha of which 70,000-80,000 ha are of eucalypt species. The planting material of eucalypts can be divided into 70% from seed and 30% from vegetative propagation means especially rooted cuttings. There are also large areas of eucalypt plantations, especially E. camaldulensis and E. tereticornis, regenerated by coppicing after harvesting. 2 Genetic Improvement of Eucalyptus species in Vietnam The Forest Science Institute of Vietnam (FSIV) through the Research Centre for Forest Tree Improvement (RCFTI) is the leading government agency conducting genetic improvement of eucalypts in Vietnam. A great deal of this work is in cooperation with FSIV regional centres such as those in central and southern Vietnam. Other agencies conducting or involving in tree improvement work include Phu Tho Forestry Research Centre and some of the Provincial forest departments. The work program is described in the following sections. 2.1 Candidate Plus Tree Selection and Clonal Testing Prior to mid 1990s, the focus of genetic improvement was on selection of locally grown superior trees of E. camaldulensis and E. urophylla, followed by clonal testing for high productivity and adaptability. Some highly productive eucalypt clones of E. urophylla and its interspecific hybrids were also imported for planting, e.g. from China. In 1993, a clonal trial testing 38 clones of E. camaldulensis selected from a 4-year-old plantation was established at Cam Qui, Ha Tay province. Diameter and height of all selected trees exceeded the plantation mean by more than 1.5 standard deviations. Eight clones were found to perform better than commercial seed of E. camaldulensis (C), E. exserta (E), E. urophylla (U) and a natural hybrid E. exserta x E. camaldulensis (EC). Results at 7 years showed that 26 clones grew faster than E. camaldulensis control and 12 were poorer. The stem volumes of the two fastest clones C22 and C7 were two times greater than the E. urophylla seedling control and three times greater than the E. camaldulensis clones. The trial provided a good lesson to local forest research institutes the essential need to field-test clonal selections. Candidate plus trees of E. urophylla were also clonally tested. The Forestry Research Centre in Phu Tho has selected many superior individuals of E. urophylla from plantations and provenance trials and tested them in clone trials. Some of these are now listed as commercial clones: PN 2 , PN 3d , PN 10 , PN 14 , PN 24 , PN 46 , PN 47 and PN 108 . These clones performed better than two imported clones, U 6 (urophylla) and GU 8 (grandis x urophylla), from China. However, PN 2 was later found to be very susceptible to leaf blight disease caused by Phaephleospora destructans (Nguyen Hoang Nghia 2003). 2.2 Development of Eucalypt Hybrids From the early 1990s, very positive results have been gained by integration of plus tree selection of three parental species: E. camaldulensis (C), E. exserta (E) and E. urophylla (U), followed by controlled pollination to produce pure-species and interspecific hybrid crosses and field testing to develop superior clones. Studies on flowering biology, pollen collection 9 and storage and controlled pollination techniques were carried out for all three species. By controlled pollination, reciprocal hybridisation between the three species has been conducted and more than 70 inter- and intraspecific hybrid combinations have been made. Some of the interspecific hybrid families created by RCFTI have out-performed their parental species in terms of volume growth by 100-300%. Results from this work were reported in Le Dinh Kha et al. (2003a). In general, the hybrid combination UC grows well on the deep soils of the Red River delta and seasonally waterlogged, acid sulphate soils in Kien Giang province. Hybrid combinations UE and EU are usually fast-growing on hill sites. Intraspecific crosses within E. urophylla also perform well in these environments. Hybrid combinations EC and CE are the slowest among the hybrid combination created. Their growth is only slightly better than the open- pollinated offspring of their parent trees. The performance of individual hybrid and pure- species families can be classified into the following groups (suffixes refer to parent tree numbers): (i) Fast growing hybrid combinations for hill sites, deep and fertile soils in Red River delta and acid sulphate soils in Kien Giang (Mekong Delta): U 15 C 4 , U 29 E 1 , U 29 E 2 and E 2 U 29 . (ii) Fast growing hybrid combinations for deep and fertile soils in Red River delta and acid-sulphate soils in Kien Giang: U 29 C 3 , U 29 C 4 , and possibly U 29 U 27 . (iii) Fast growing hybrid combinations for hill sites at Ba Vi and Dong Ha: U 29 E 1 , U 29 E 6 , E 4 U 29 , U 29 U 26 and U 29 U 24 . 2.3 Open Pollinated Progeny Trials Developed into Seedling Seed Orchards From mid 1990s to early 2000s, with funding support from Vietnam government, ACIAR and AusAID, and cooperation of CSIRO scientists, RCFTI established open pollinated progeny trials integrated with seedling seed orchards of key species including E. camaldulensis, E. grandis, E. pellita, E. tereticornis and E. urophylla. These plantings were initially established as provenance-progeny trials, and are assessed and selectively thinned as they develop. They are very important not only to supply seed, but also for selecting the most promising provenances, families and superior individuals for further genetic improvement. Together, these plantings now provide most of the breeding populations for genetic improvement programs in Vietnam. Details of these plantings are discussed in Section 4.5. 2.4 The Need for a Genetic Improvement Strategy and Plan To date the RCFTI has done an excellent job of conducting genetic improvement of key Eucalyptus species. Many genetic trials have been established and superior trees selected for inter- and intraspecific hybrid crossing programs. Many individual hybrid trees from different combinations have been recognised by the Ministry of Agriculture and Rural Development as Technological-Advanced Germplasm. However, all these works have been conducted without a written breeding plan that follows a clearly defined genetic improvement strategy. As part of an AusAID CARD project (058/04VIE), Strengthening Capacity in Forest Tree Seed Technologies Serving Research and Development Activities and ex-situ Conservation, we define the breeding strategy for the selected Eucalyptus species and put together a written plan so that it can be used as a practical guide for long-term management of eucalypt improvement in Vietnam. 10 [...]... breeding population to obtain genetic information and make accurate selections of outstanding trees for clone bank and advanced breeding Convert to seedling seed orchards after selective thinning Two trials were established at Phu Ninh in 1996 and at Ba Vi in 1997 144 open-pollinated families from natural provenances in Indonesia Randomised latinised row-column design with 8 replicates, 4 -tree line... genetic information and make accurate selections of outstanding trees for clone bank and advanced breeding Convert to seedling seed orchards after selective thinning Two trials were established at Bau Bang and Pleyku 105 open-pollinated families from natural provenances in Indonesia, PNG and seed orchards in northern Australia Randomised latinised row-column design, 8-10 replicates, 4 -tree line plot in. .. plot in each replicate, spacing 4m between row and 1.5m within rows (1666/ha) First thinning at 3 years of age in 1999 in Phu Ninh trial and 2000 in Ba Vi selection was within family only, the biggest straightest tree was retained in each line plot and 3 trees were removed The trees to remove were selected by eye, not from the results of statistical analysis, but after measuring all trees for height and. .. diameter reduce stocking to maintain vigorous growth of remaining trees and promote early flowering Selection of outstanding trees for grafting into clone bank around 10 years identify the best 30 trees from the 15 families using multi-trait index selection, incorporating growth, form traits and wood density selected trees will be used to form the ‘Elite Population’ as described in section 5.3.2 Selection... Convert to seedling seed orchards after selective thinning three trials were established at Cam Lo, Ham Thuan Nam and Phu Yen 105-144 open-pollinated families from natural provenances in Queensland and Papua New Guinea Randomised latinised row-column design, 6-8 replicates, 4 -tree line plot in each replicate, spacing 3m x 2m at Cam Lo and 4m x 1.5 m at Ham Thuan Nam and Phu Yen Purpose First thinning (Ham... spacing 4 m between rows and 1.5m within rows The trial at Bau Bang consists of 10 replicates and that at Pleyku 8 replicates 6.2.1.1 First thinning Although both trials are developing well with satisfactory growth, more intensive management has been put in the trial at Bau Bang, including the first thinning at two years of age in 2004 At this first thinning 2 trees were removed, retaining the best 2 trees... distribution in Australia, Papua New Guinea and Indonesia In addition seed- orchard seedlots 16 were included for E pellita and E tereticornis Details of the provenances and number of families representing in each breeding population are given in Tables 2-6 At present greater effort and resources are put into E urophylla as the highest priority species for pure species and interspecific hybrid breeding Breeding... generation breeding population of E pellita was established as open-pollinated progeny trials in 2002 at Bau Bang, Binh Duong and at Pleyku, Gia Lai Both trials consisted of 105 open-pollinated families from natural provenances in Papua New Guinea and Indonesia and superior trees in seed orchards in northern Australia (Table 3) They were planted using randomised latinised row-column designs, 4 -tree line plots,... larger or main subpopulation of the breeding population 3.4 Selection and Mating Selection and mating are key activities in breeding They accumulate genes which influence yield and adaptation, increasing over successive generations the frequency of superior trees Every successful breeding strategy, therefore, requires efficient methods of selecting superior material including the progeny tests in which... replicate, spacing 4m between row and 1.5m within rows (1666/ha) First thinning (Bau Bang trial only) 2 years selection was within family only, the 2 biggest straightest tree were retained in each line plot and 2 trees were removed The trees to remove were selected by eye, not from the results of statistical analysis, but after measuring all trees for height and diameter reduce stocking to maintain vigorous . 058/04VIE) Strengthening Capacity in Forest Tree Seed Technologies Serving Research and Development Activities and ex-situ Conservation a genetic improvement plan has been developed focusing on. Ministry of Agriculture & Rural Development Collaboration for Agriculture and Rural Development Strengthening Capacity in Forest Tree Seed Technologies Serving Research and Development. such as those in central and southern Vietnam. Other agencies conducting or involving in tree improvement work include Phu Tho Forestry Research Centre and some of the Provincial forest departments.