G.F. Moran et al.Genes for eucalyptus wood Note Genomics of Eucalyptus wood traits Gavin F. Moran a* , Karen A. Thamarus b , Carolyn A. Raymond c , Deyou Qiu a , Tom Uren a and Simon G. Southerton a a CSIRO Forestry and Forest Products, PO Box E4008, Kingston, ACT 2604, Australia b CSIRO Forestry and Forest Products and CRC Sustainable Production Forestry, PO Box E4008, Kingston, ACT 2604, Australia c CSIRO Forestry and Forest Products and CRC Sustainable Production Forestry, GPO Box 252-12, Hobart, TAS 7001, Australia (Received 5 July 2001; accepted 29 March 2002) Abstract – A major focus of our research has been on using molecular technologies to guide breeding for high value wood and fibre traits in eu - calypts. One approach has been to use genomic maps to locate and characterise QTL that control wood and fibre traits. A generic map for euca - lypts has been developed that consists of codominant markers that can be assayed across the major commercial species. Also on the map are candidate genes for traits such as flowering and wood and fibre traits. QTL have been characterised for wood density, fibre length, pulp yield and microfibril angle. A number of these have been validated in a related pedigree. A subset of QTL colocates with candidate genes. Research is now focussed on DNA sequence variation in different parts of these candidate genes and determining if this variation is associated with variation in wood properties. Of particular interest are genes involved in fibre development and cell wall formation. A third approach is to profile the expres- sion of genes in the tissue of interest and determine if this relates to variation in trait performance. Microarrays are being used to relate expression of several thousand genes in xylem tissue to variation in traits such as microfibril angle and density. eucalypt / linkage maps / QTL / candidate genes / xylem / microarrays Résumé – Génomique des critères de qualité du bois d’eucalyptus. Notre recherche a été concentrée sur l’utilisation de technologies molécu- laires pour guider l’amélioration génétique de critères importants de la qualité du bois et des fibres. On a développé une carte générique pour les eucalyptus à partir de marqueurs co-dominants intéressant les principales espèces d’intérêt commercial. Figurent également sur cette carte des gènes candidats concernant des caractères tels que la floraison et la qualité du bois et des fibres. On a mis en évidence des QTL pour la densité du bois, la longueur des fibres, le rendement en pâte et l’angle des microfibrilles. Un certain nombre ont été validés sur des familles apparentées à généalogie connue. Un sous ensemble de QTL sont co-localisés avec des gènes candidats. On concentre maintenant les recherches sur la variabi - lité de séquences ADN de ces gènes candidats pour savoir si elle est associée à celle des critères de qualité du bois. Sont d’un intérêt particulier les gènes impliqués dans le développement des fibres et la formation des parois cellulaires. Une troisième approche consiste à profiler l’expres - sion des gènes dans les tissus en cause et à rechercher s’il existe d’éventuelles relations avec la variabilité des caractères. On utilise des microré - seaux pour relier l’expression de plusieurs milliers de gènes du xylème avec la variabilité de caractères tels que l’angle des microfibrilles et la densité du bois. eucalyptus / carte de liaison / QTL / gènes candidats / xylème / microréseaux 1. INTRODUCTION Until recently the selection and breeding for wood and fi - bre traits has been significantly limited in eucalypts by the ability to measure rapidly large numbers of specific traits at reasonable cost [6, 15]. In Australia the traditional breeding programs have focussed on yield, form etc. and, with auto - mated coring, average wood density. In the last ten years non-destructive, cost effective methods have been developed for measuring a suite of wood and fibre traits such as microfibril angle, pulp yield, cellulose levels, fibre character - istics, etc. [6]. With the accurate determination of wood and fibre phenotypes for large numbers of individuals, the Ann. For. Sci. 59 (2002) 645–650 645 © INRA, EDP Sciences, 2002 DOI: 10.1051/forest:2002050 * Correspondence and reprints Tel.: 61 2 62818208; fax: 61 2 62818233; e-mail: gavin.moran@csiro.au molecular genetic dissection of these traits became feasible. In the late 1980’s the use of DNA markers became routine in forest trees and the construction of genetic maps a reality. The second generation of these maps in eucalypts are proving to be strong tools in locating and mapping genetic compo - nents (QTL) of wood and fibre traits [18]. As part of this pro - cess, and given the availability of the complete DNA sequence of Arabidopsis and soon rice, candidate genes are now being placed on these maps. Here a candidate gene is de - fined as any gene putatively involved in trait variation, based on its biological function and/or its map position [14]. When such genes colocate with QTL positions on a map there is the incentive to look at variation in the gene itself and see if this relates to variation in traits. The arrival of microarray tech - nology has enabled the monitoring of the expression of many genes simultaneously in specific tissues. It is being used to determine what genes are expressed in xylem tissue and how that expression relates to variation in wood and fibre traits. In this paper the current state of Australian research in these ar - eas on the temperate eucalypts, E. globulus and E. nitens,is summarised with emphasis on the considerable advantages of the integration of these approaches. 2. CANDIDATE GENES AND GENETIC LINKAGE MAPS In forest trees, the Holy Grail has been early selection us- ing molecular markers as tags to QTL for high value traits such as pulp yield and wood density. Primarily anonymous markers have been used, either dominant markers such as RAPDs and AFLPS or codominant RFLPs and microsatellite markers. In eucalypts RFLPs were developed first [3] and were the principal markers used to construct a genetic linkage map in E. nitens [4]. In contrast the first generation maps made from interspecific pedigrees were based initially on RAPDs [9, 19] and subsequently on AFLPs [12]. In the meantime microsatellite loci were developed in a number of eucalypts [2, 5, 8, 17] and have been shown to be highly informative and generally assayable across the impor - tant commercial species. Subsequent mapping has included candidate genes and has led to more powerful second genera - tion maps [7, 18] and moves toward a generic map for eucalypts. As stated previously candidate genes may be identified empirically as genes that collocate to the map position of a QTL or they could be candidates because they belong to bio - chemical pathways known to be involved in trait expression. For wood and fibre traits, examples would be genes in the cel - lulose and lignin biosynthetic pathways. Of fifty putative genes on the genetic linkage map of E. globulus, forty-one genes correspond to known proteins or have homology to genes of known function (figure 1) [18]. The loci seemed to be randomly distributed in the genome, with little evidence that genes encoding enzymes in the same pathway are not randomly distributed across the genome. For instance the five lignin genes are on different linkage groups, the two xylan synthase genes [16] on linkage groups 5 and 6. The 32 candidate genes for wood and fibre traits include 10 known genes and 22 cambial-specific expressed sequence tags (ESTs). The source of these genes is given in table I. 3. QTL FOR WOOD AND FIBRE TRAITS Studies have been undertaken to characterise QTL for wood and fibre traits in E. globulus, the major hardwood plantation species in Australia. The aim is to use this informa- tion to better understand the genetic components of these im- portant traits and to develop more efficient and cost effective selection procedures. Two fullsib pedigrees were chosen that had a common male parent and were planted in field trials in 1990 at seven sites across southern Australia (Thamarus, pers. comm.). Each family was represented by four or more replicates per site and a 5 tree row plot per replicate. One of these was an interprovenance cross with 148 progeny and was used as the test pedigree. It was also used to construct the detailed genetic linkage map shown in figure 1 [18]. The sec - ond cross was an intraprovenance cross with 135 progeny and was used to validate QTL. At the age of 7 years, three wood cores were taken from all progeny and used to measure basic wood density, fibre length, percent cellulose content, predicted pulp yield and microfibril angle. Details of methods of assessment of traits are given by Raymond [15]. ANOVAs were performed for progeny of the test pedigree to test for significant marker-trait associations at the 1% level of probability. The data set consisted of genotypes at 249 codominant loci and quantita - tive data for the 5 traits. The locations of putative QTL for these traits are shown in figure 2. As shown on the map, there were five putative QTL for basic wood density, four for microfibril angle, three for pulp yield, and three for both cel - lulose content and fibre length. There were QTL locations on all linkage groups except 3 and 6 and a minimum of 13 sepa - rate QTL positions. Clearly there could be pleiotropic effects and some QTL positions may affect two traits. Some of these are not unexpected such as the QTL positions on linkage groups 4 and 10, which are significant for both pulp yield and cellu - lose. However, it is interesting to note that there is a QTL for cellulose on linkage 11 that does not occur for pulp yield. 646 G.F. Moran et al. Table I. Types of known potential candidate genes for wood traits mapped in E. globulus. Type of candidate gene Numbers Sources Cambial–specific ESTs 22 Bossinger [1] Lignin biosynthesis 5 Thamarus [18] Cell wall polysaccharide biosynthesis 5 Southerton CSIRO unpublished Similarly, two QTL for microfibril angle on linkage groups 7 and 8 collocate with QTL for pulp yield and fibre length re - spectively. It is also noticeable that for most of the QTL, the effect is primarily coming from one side of the cross. Since the two pedigrees have a common male parent, but different female parents, the use of the second pedigree for validation can only strictly check QTL effects from the male parent. Thus table II shows which QTL/marker associations were significant from ANOVA analyses in the second cross and also those not strictly tested as yet (i.e. those sourced from the female parent in the test pedigree). A total of at least seven QTL appear to be validated with this data. Some clearly were not validated despite accurate assessments of traits. It is noteworthy that for density and pulp yield, which are known to be fairly highly heritable [15], no QTL have been invalidated. In the QTL analyses some false positives were found, probably in part because total progeny sample sizes were limited and progeny were located across a number of field trials. Gen - erally, individual QTL explained or accounted for only a small proportion of the total phenotypic variation, similar to that found in loblolly pine [13]. For instance the different wood density QTL explained from 5.4% to 6.5% of the varia - tion. Work is now in progress to test the transference and oc - currence of these QTL in E. nitens. The checking of QTL across studies from other laboratories [10] will require inte - gration of maps, which is now possible with the mapping of microsatellites and known genes. Genes for eucalyptus wood 647 5 Eg115 Eg015a g339 Eg067 Eg089 g425 c378 g010 g154/1 e314 Es140 e344a c198 EXS2 g435 Pgd-1 c307 g003 0 2 16 19 21 26 44 51 55 64 65 66 70 74 80 92 95 6 g466 9 Embra 5 c305 g034 c288 c135 g471 c337 c021 g080a g430 AGE2 g080g g174 e345b g107 c211b 11 22 49 62 64 65 74 85 96 102 109 110 113 0 g234 11 En011 g047 g186 Eg128 g158 c401 g118 c176a g412 Eg030 c456a g338/2 g361 g261 MsaS2 0 5 23 27 32 39 43 45 57 60 69 85 88 90 17 12 g373 c505b g479 0 6 12 12 g373 c505b g479 0 6 12 g373 c505b g479 0 6 12 6 EXS1 g063 g467 c334/1 Eg015b Gpi-2 Eg062 En016 g195 g221 e319 g093 g015 e346 Ugp-3 c427 g125 g428 0 17 25 34 41 56 59 75 77 85 86 100 120 139 150 155 157 5 e376 g283 c211c e348 1 11 15 28 41 60 68 70 74 76 81 83 91 94 100 102 107 108 118 122 125 137 143 155 158 163 165 167 0 e345c g098 c087a c030/6 g089 g117 g465 g334 En013 Mdh2- c176b e301 c104 e331 e377 c158 c453 e345d e343 c333 c435 g212 c397 En015 c489b c007 Es076 c354 Eg117 g040 Eg126 c102 g293 c016 En010 2 CCoAOMT c113 g005 e371 c069c g099 g032 g423 Eg061 e378 En012 g405 e340 En014 e360a glg065 e364 g021 g235 c137 g419 ECA1 0 2 5 12 14 23 37 40 41 43 46 47 51 59 60 64 66 74 85 91 101 g257 g478 3 g427 4CL e370b g080d e329 g080f g086 AGE1 c449 Eg099 c380b c109 ELF1 c251 g482 Embra 2 g417 Eg024 c077 c115 0 10 12 26 28 32 33 36 49 70 72 82 85 110 121 123 126 129 131 1 4 Eg008 g233 g418 g474 g258 c187 EAP1 g256 g142 c505a e330b g131 Eg111 g019 PAL g421 g080e g314 c018 c008 Eg086 c083 c010/8 e344b g342 g198 Eg096 0 11 14 16 23 27 29 33 37 42 44 45 56 57 64 68 70 73 96 102 120 122 129 139 143 145 1 Eg076 g092 c092 7 Embra 6 g069 g133 En006 Eg084 c456b e310 Eg065 g248 e330 a COMT e370a Eg134 c170 c211a c380c g196 c373/1 0 2 4 22 25 28 29 40 46 48 52 64 70 78 97 101 105 6 e365 c395 8 g041 e345a ECS1 c165a g338/1 g337 Eg094 c452/4 c116 g350 g402c g472 g409 g402d e353 Eg098 Aat-3 g042 g336a e351 g149 g268 Eg131 g402e c165b g243 0 2 3 4 5 8 11 40 58 65 80 88 91 92 93 98 101 103 106 107 123 141 147 149 150 c451 17 10 c456c CCR Eg023 g197 c087b g297 c010/1 e360b c136 c089 c482 g250 e358 Es115 c238 c069a 0 8 17 19 39 42 49 54 60 62 61 70 87 106 109 6 Eg091 31 expressed sequence tags 14 flowering or wood fibre candidate genes 5 isozymes Figure 1. A genetic linkage map of E. globulus with ESTs, candidate genes and isozymes in bold. Anonymous RFLPs and microsatellite loci are in ordinary type. See [18] for details of map construction. Table II. QTL for wood and fibre traits in E. globulus. Trait No. Putative QTL a Validated QTL b QTL not tested c Density 5 2 2 Pulp yield 3 2 1 Cellulose levels 3 0 1 Fibre length 3 1 1 Microfibril angle 4 2 0 a As shown in figure 2, b QTL that were significant in the second pedigree at the 1% level of significance from ANOVA analyses, c QTL segregating of female side in test pedigree. 648 G.F. Moran et al. 50 0 25 75 100 150 125 50 0 25 75 100 150 125 1 e345c g098 c087a c030/6 g089 g117 g465 g334 En013 Mdh-2 c176b e301 c104 e331 e377 c158 c453 e345d e343 c333 c435 g212 c397 En015 c489b c007 Es076 c354 Eg117 g040 Eg126 c102 g293 c016 En010 M 1 e345c g098 c087a c030/6 g089 g117 g465 g334 En013 Mdh-2 c176b e301 c104 e331 e377 c158 c453 e345d e343 c333 c435 g212 c397 En015 c489b c007 Es076 c354 Eg117 g040 Eg126 c102 g293 c016 En010 1 e345c g098 c087a c030/6 g089 g117 g465 g334 En013 Mdh-2 c176b e301 c104 e331 e377 c158 c453 e345d e343 c333 c435 g212 c397 En015 c489b c007 Es076 c354 Eg117 g040 Eg126 c102 g293 c016 En010 e345c g098 c087a c030/6 g089 g117 g465 g334 En013 Mdh-2 c176b e301 c104 e331 e377 c158 c453 e345d e343 c333 c435 g212 c397 En015 c489b c007 Es076 c354 Eg117 g040 Eg126 c102 g293 c016 En010 M Embra5 9 c305 g034 c288 c135 g471 c337 c021 g080a g430 AGE2 g080g g174 e345b g107 c211b g234 F Embra5 9 c305 g034 c288 c135 g471 c337 c021 g080a g430 AGE2 g080g g174 e345b g107 c211b g234 Embra5 9 c305 g034 c288 c135 g471 c337 c021 g080a g430 AGE2 g080g g174 e345b g107 c211b g234 9 c305 g034 c288 c135 g471 c337 c021 g080a g430 AGE2 g080g g174 e345b g107 c211b g234 F 4 Eg008 g233 g418 g474 g258 c187 EAP1 g256 g142 c505a e330b g131 Eg111 g019 PA L g421 g080e g314 c018 c008 Eg086 c083 c010/8 e344b g342 g198 Eg096 Eg076 g092 c092 F F 4 Eg008 g233 g418 g474 g258 c187 EAP1 g256 g142 c505a e330b g131 Eg111 g019 PA L g421 g080e g314 c018 c008 Eg086 c083 c010/8 e344b g342 g198 Eg096 Eg076 g092 c092 F 4 Eg008 g233 g418 g474 g258 c187 EAP1 g256 g142 c505a e330b g131 Eg111 g019 PA L g421 g080e g314 c018 c008 Eg086 c083 c010/8 e344b g342 g198 Eg096 Eg076 g092 c092 4 Eg008 g233 g418 g474 g258 c187 EAP1 g256 g142 c505a e330b g131 Eg111 g019 PA L g421 g080e g314 c018 c008 Eg086 c083 c010/8 e344b g342 g198 Eg096 Eg076 g092 c092 F F 10 c456c CCR Eg023 g197 c087b g297 c010/1 e360b c136 c089 c482 g250 e358 Es115 c238 c069a Eg091 F F 10 c456c CCR Eg023 g197 c087b g297 c010/1 e360b c136 c089 c482 g250 e358 Es115 c238 c069a Eg091 10 c456c CCR Eg023 g197 c087b g297 c010/1 e360b c136 c089 c482 g250 e358 Es115 c238 c069a Eg091 F FF 11 En011 g047 g186 Eg128 g158 c401 g118 c176a g412 Eg030 c456a g338/2 g361 g261 MsaS2 M F M 11 En011 g047 g186 Eg128 g158 c401 g118 c176a g412 Eg030 c456a g338/2 g361 g261 MsaS2 11 En011 g047 g186 Eg128 g158 c401 g118 c176a g412 Eg030 c456a g338/2 g361 g261 MsaS2 MM FF M 5 Eg115 Eg015a g339 Eg067 Eg089 g425 c378 g010 g154/1 e314 Es140 e344a c198 EXS2 g435 Pgd-1 c307 g003 g466 F 5 Eg115 Eg015a g339 Eg067 Eg089 g425 c378 g010 g154/1 e314 Es140 e344a c198 EXS2 g435 Pgd-1 c307 g003 g466 5 Eg115 Eg015a g339 Eg067 Eg089 g425 c378 g010 g154/1 e314 Es140 e344a c198 EXS2 g435 Pgd-1 c307 g003 g466 FF density pulp yield cellulose fibre length microfibril angle density pulp yield cellulose fibre length microfibril angle 2 CCoAOMT c113 g005 e371 c069c g099 g032 g423 Eg061 e378 En012 g405 e340 En014 e360a glg065 e364 g021 g235 c137 g419 ECA1 g257 g478 F M 2 CCoAOMT c113 g005 e371 c069c g099 g032 g423 Eg061 e378 En012 g405 e340 En014 e360a glg065 e364 g021 g235 c137 g419 ECA1 g257 g478 2 CCoAOMT c113 g005 e371 c069c g099 g032 g423 Eg061 e378 En012 g405 e340 En014 e360a glg065 e364 g021 g235 c137 g419 ECA1 g257 g478 CCoAOMT c113 g005 e371 c069c g099 g032 g423 Eg061 e378 En012 g405 e340 En014 e360a glg065 e364 g021 g235 c137 g419 ECA1 g257 g478 F M Embra6 7 g069 g133 En006 Eg084 c456b e310 Eg065 g248 e330a COMT e370a Eg134 c170 c211a c380c g196 c373/1 e365 c395 F M F Embra6 7 g069 g133 En006 Eg084 c456b e310 Eg065 g248 e330a COMT e370a Eg134 c170 c211a c380c g196 c373/1 e365 c395 Embra6 7 g069 g133 En006 Eg084 c456b e310 Eg065 g248 e330a COMT e370a Eg134 c170 c211a c380c g196 c373/1 e365 c395 7 g069 g133 En006 Eg084 c456b e310 Eg065 g248 e330a COMT e370a Eg134 c170 c211a c380c g196 c373/1 e365 c395 F M FF 8 g041 e345a ECS1 c165a g338/1 g337 Eg094 c452/4 c116 g350 g402c g472 g409 g402d e353 Eg098 Aat-3 g042 g336a e351 g149 g268 Eg131 g402e c165b g243 c451 F F M 8 g041 e345a ECS1 c165a g338/1 g337 Eg094 c452/4 c116 g350 g402c g472 g409 g402d e353 Eg098 Aat-3 g042 g336a e351 g149 g268 Eg131 g402e c165b g243 c451 8 g041 e345a ECS1 c165a g338/1 g337 Eg094 c452/4 c116 g350 g402c g472 g409 g402d e353 Eg098 Aat-3 g042 g336a e351 g149 g268 Eg131 g402e c165b g243 c451 F F M cM Figure 2. Location of putative QTL for wood and fibre traits on the E. globulus linkage map. Only linkage groups with QTL locations are shown. F and M indicate positive QTL effect comes from female and male parents respectively. 4. QTL AND CANDIDATE GENE VARIATION An outcome of the QTL studies has been a greater focus on the candidate genes and anonymous cDNA RFLP probe loci associated with QTL map positions. Work is underway to se - quence cDNA probes mapped within a few centiMorgans of wood density and other QTL and see whether they are homol - ogous to known genes. A second approach is to look at DNA sequence variation in the few candidate genes collocating to the characterised QTL. Here the approach being adopted is to focus on open-pollinated trees from across the range of E. nitens and E. globulus, which exist in field trials and have for which trait data can readily be obtained. The aim is to test for associations between allelic variation at the sequence level and variation in traits such as wood density. However the environmental variation within such trials will have to be kept to a minimum and substantial sample sizes may be re - quired. 5. XYLEM GENE EXPRESSION AND VARIATION IN WOOD TRAITS A cDNA library from xylem tissue of E. grandis was con- structed and used to characterise the eucalypt homologues of several known genes involved in cell wall formation (Southerton unpublished). The library has also been used to create xylem microarrays containing about 4500 cDNA genes. It is envisaged that this will allow changes in expres- sion (messenger RNA abundance) of all these genes to be measured simultaneously in relation to changes in wood and fibre traits. This parallel hybridisation of high density arrays of nucleic acids on glass slides (DNA microarrays) promises to define much more effectively both known and unknown genes that are expressed in particular biological tissues [11]. The first application of these xylem microarrays has been to compare patterns of xylem gene expression in tension wood and non-tension (relaxed) wood in eucalypts. Fifteen genes were found to be up- or down- regulated more than twofold compared to normal wood (Qiu, Uren and Southerton unpublished). Two of these shared strong homology with hypothetical Arabidopsis genes of unknown function identified during the sequencing of the Arabidopsis genome. It was noteworthy that four genes, some of which were highly expressed, belong to a family of arabinogalactan proteins. This result seems analogous to that found using a different approach in compression wood in softwoods [20]. Tension wood is a significant problem in young plantations of E. globulus in Australia, and these results provide a new starting point to understand the molecular processes control - ling this trait. The strategy is to identify candidate genes for wood fibre traits by analysing gene expression in xylem from 7-year-old progeny in a controlled cross pedigree of E. nitens. RNA is isolated from xylem tissue for each progeny to assess gene expression and cores taken from each progeny will allow quantifying of phenotypes for wood traits. At the same time marker assays will allow location of existing and perhaps new QTL for the wood fibre traits. RNA will be pooled from trees having phenotypic extremes of traits and will be used to synthesise fluorescent cDNA probes, for differentially prob - ing of the xylem microarrays. RNA pools could also be made from trees possessing different alleles at loci associated with QTL. Candidate genes will be those that are up-regulated or down-regulated and will be sequenced and mapped. Those genes collocating with QTL will be targeted for further analy - sis. It can be seen that the integration of a number of technolo - gies not available 10 years ago, promise an unravelling of the molecular basis of wood formation and may ultimately lead to more efficient selection methods for desirable wood fibre traits. 6. THE WAY FORWARD – INTEGRATING TECHNOLOGIES In future our mapping of additional loci will be selective and focussed on candidate genes targeted because of their de- tection in association with desirable traits through gene ex- pression and other molecular methods. In addition our research approaches will integrate, as much as possible, the new and emerging molecular and wood assessment technolo- gies. The ultimate goal is to understand which genes are criti- cal in controlling trait formation so that propagules with higher value wood and fibre traits can be produced through marker-assisted breeding, selection at the actual genes, or manipulation of the genes through genetic engineering. REFERENCES [1] Bossinger G., Leitch M.A., Isolation of cambium specific genes from Eucalyptus globulus Labill, in: Savidge R., Barnett J., Napier R. (Eds.), Cell and Molecular Biology of Wood Formation, BIOS Scientific, Oxford, 2000, pp. 203–207. [2] Brondani R.P.V., Brondani C., Tarchini R., Grattapaglia D., Develop - ment, characterization and mapping of microsatellite markers in Eucalyptus grandis and E. urophylla, Theor. Appl. Genet. 97 (1998) 816–827. [3] Byrne M., Moran G.F., Murrell J.C., Tibbits W.N., Detection and inhe - ritance of RFLPs in Eucalyptus nitens, Theor. Appl. Genet. 89 (1994) 397–402. [4] Byrne M., Murrell J.C., Allen B., Moran G.F., An integrated genetic linkage map for eucalypts using RFLP, RAPD and isozyme markers, Theor. Appl. Genet. 91 (1995) 869–875. [5] Byrne M., Marques-Garcia M.I., Uren T., Smith D.S., Moran G.F., Conservation and genetic diversity of microsatellite loci in the genus Eucalyp - tus, Aust. J. Bot. 44 (1996) 331–341. [6] Downes G.M., Hudson I.L., Raymond C.A., Dean G.H., Michell A.J., Schimleck L.R., Evans R., Muneri A., Sampling Plantation Eucalypts for Wood and Fibre Properties, CSIRO Publishing, Melbourne, 1997. [7] Gion J.M., Rech P., Grima-Pettenati J., Verhaegen D., Plomion C., Mapping candidate genes in Eucalyptus with emphasis on lignification genes, Mol. Breed. 6 (2000) 441–449. Genes for eucalyptus wood 649 [8] Glaubitz J.C., Emebiri L.C., Moran G.F., Dinucleotide microsatellites from Eucalyptus sieberi: inheritance, diversity and improved scoring of single-base differences, Genome 44 (2001) 1041–1045. [9] Grattapaglia D., Sederoff R.R., Genetic linkage maps of Eucalyptus grandis and Eucalyptus urophylla using a pseudo-testcross: Mapping strategy and RAPD markers, Genetics 137 (1994) 1121–1137. [10] Grattapaglia D., Bertolucci F.L.G., Penchel R., Sederoff R.R., Gene - tic mapping of quantitative trait loci controlling growth and wood quality traits in Eucalyptus grandis using a maternal half-sib family and RAPD markers, Genetics 144 (1996) 1205–1214. [11] Lockhart D.J., Winzeler E.A., Genomics, gene expression and DNA arrays, Nature 405 (2000) 827–836. [12] Marques C.M., Araújo J.A., Ferreira J.G., Whetten R., O’Malley D.M., Liu B H., Sederoff R., AFLP genetic maps of Eucalyptus globulus and E. tereticornis, Theor. Appl. Genet. 96 (1998) 727–737. [13] Neale D.B., Sewell M.M., Brown G.R., Molecular dissection of the quantitative inheritance of wood property traits in loblolly pine, Ann. For. Sci. 59 (2002) 595–605. [14] Pflieger S., Lefebvre V., Causse M., The candidate gene approach in plant genetics: a review, Mol. Breed. 7 (2001) 275–291. [15] Raymond C.A., Genetics of Eucalyptus wood properties, Ann. For. Sci. 59 (2002) 525–531. [16] Somerville C., Cutler S., Use of genes encoding xylan synthase to mo - dify plant cell wall composition, International Patent Number WO 98/55596, 1998. [17] Steane D.A., Vaillancourt R.E., Russell R., Powell W., Marshall D., Potts B.M., Development and characterisation of microsatellite loci in E. glo - bulus (Myrtaceae), Silvae Genet. 50 (2001) 89–91. [18] Thamarus K.A., Groom K., Murrell J., Byrne M., Moran G.F., A genetic linkage map for Eucalyptus globulus with candidate loci for wood, fibre and floral traits, Theor. Appl. Genet. 104 (2002) 379–387. [19] Verhaegen D., Plomion C., Genetic mapping in Eucalyptus urophylla and Eucalyptus grandis using RAPD markers, Genome 39 (1996) 1051–1061. [20] Zhang Y., Sederoff R.R., Allona I., Differential expression of genes encoding cell wall proteins in vascular tissues from vertical and bent pine trees, Tree Physiol. 20 (2000) 457–466. To access this journal online: www.edpsciences.org 650 G.F. Moran et al. . G.F. Moran et al.Genes for eucalyptus wood Note Genomics of Eucalyptus wood traits Gavin F. Moran a* , Karen A. Thamarus b , Carolyn A. Raymond c ,. and wood and fibre traits. QTL have been characterised for wood density, fibre length, pulp yield and microfibril angle. A number of these have been validated in a related pedigree. A subset of. developed for measuring a suite of wood and fibre traits such as microfibril angle, pulp yield, cellulose levels, fibre character - istics, etc. [6]. With the accurate determination of wood and fibre phenotypes