Tran Ho Quang

Publications (6) View all

• Article: Cellulose content as a selection trait in breeding for kraft pulp yield in Eucalyptus urophylla

  Nguyen D. Kien, Tran H. Quang, Gunnar Jansson, Chris Harwood, David Clapham, Sara von Arnold
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  ABSTRACT: • The aim of this study was to investigate the effectiveness of using cellulose content, measured by the diglyme-HCl method, as a selection trait in breeding programs for kraft pulp yield in Eucalyptus urophylla. • A total of 275 trees from sixty-two families were sampled from a thinned progeny trial of E. urophylla in northern Vietnam to evaluate cellulose content from breast-height increment cores. Among those, twenty unrelated trees were felled to evaluate cellulose content and pulp yield from breast-height disk samples. • The regression of pulp yield of disk samples on cellulose content was strong either from disks ($R^{2}$ = 0.83) or increment cores ($R^{2}$ = 0.69). There was no significant difference in cellulose content between the provenances. The narrow-sense within-provenance heritability of cellulose content was 0.50 and the coefficient of additive genetic variation was 3.9%. Genetic correlations between cellulose content and growth (0.28–0.45) or wood basic density (–0.02) were not significantly different from zero. • Breast-height increment core cellulose content measured by diglyme-HCl method is under strong genetic control and can be used to rank trees for pulp yield in E. urophylla plantations. Selection for increased cellulose content would have only minor effects on growth and wood basic density. La teneur en cellulose comme un trait de sélection pour l'amélioration du rendement en pâte kraft d'Eucalyptus urophylla. • L'objectif de cette étude était d'étudier l'efficacité de l'utilisation de la teneur en cellulose, mesuré par la méthode diglyme-HCl, comme un trait de sélection dans les programmes d'amélioration du rendement en pâte kraft chez Eucalyptus urophylla. • Un total de 275 arbres issus de soixante-deux familles ont été échantillonnés, à partir d'un essai de descendance d' E. urophylla dans le nord du Vietnam, pour évaluer la teneur en cellulose de carottes d'accroissement prélevées à hauteur de poitrine. Parmi ces arbres, vingt ont été abattus afin d'évaluer la teneur cellulose et le rendement en pâte de disques échantillons, prélevées à hauteur de poitrine. • La régression de la production de pâte du disques échantillons a été forte sur la teneur en cellulose, soit à partir des disques ($R^{2}$ = 0.83) ou des carottes d'accroissement ($R^{2}$ = 0.69). Il n'y a pas de différence significative pour la teneur en cellulose entre les provenances. Le sens restreint dans l'héritabilité intra-provenance de la teneur de la cellulose était 0,50 et le coefficient de variation génétique additive a été de 3,9 %. Les corrélations génétiques entre la teneur en cellulose et la croissance (0,28–0,45) ou l'infra densité du bois (–0,02) ne sont pas significativement différentes de zéro. • La teneur en cellulose des carottes d'accroissement mesurée par la méthode diglyme-HCl est sous contrôle génétique fort et peut être utilisée pour classer les arbres pour le rendement en pâte dans les plantations d'E. urophylla. La sélection pour l'augmentation de la teneur en cellulose aurait seulement des effets mineurs sur la croissance et l'infra-densité du bois.
  http://dx.doi.org/10.1051/forest/2009064.
• Article: Expression of genes of cellulose and lignin synthesis in Eucalyptus urophylla and its relation to some economic traits

  Tran Ho Quang, Henrik Hallingback, Niclas Gyllenstrand, Sara von Arnold, David Clapham
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  ABSTRACT: Genes of cellulose and lignin synthesis are important for tree breeding because their activity greatly affects wood properties as well as general growth. The expression (transcript abundance) of genes of cellulose and lignin synthesis in tangential xylem scrapes at breast height sampled at the end of June (middle of active growing season) was related to wood properties in five fast-growing and six slow-growing families of Eucalyptus urophylla from a combined progeny test and seedling seed orchard grown for 10 years in northern Vietnam. Cellulose synthase A ( CesA) genes encoding proteins active in the primary cell wall, EuCesA4 and EuCesA5 , were more highly expressed than EuCesA1 , EuCesA2 and EuCesA3 , encoding genes active in the secondary cell wall. EuCesA4 expression was correlated with that of EuCesA5 ( r = 0.49, P = 0.040) and EuCesA5 with EuCesA6 ( r = 0.46, P = 0.040). EuCesA4 expression was significantly higher in the fast-growing group and was correlated with cellulose content ( r = 0.51, P = 0.011). Over 2 kb of the EuCesA gene was sequenced in 24 trees extending from the 5′ untranslated region through six exons and six introns and revealed 83 polymorphisms and rapid decay of linkage disequilibrium over 500 bp. EuCesA4 activity in xylem is involved in the genetic control of cellulose content, and the gene may have potential for marker-aided selection.
  Trees. 01/2011;
• Article: Relationship of wood composition to growth traits of selected open-pollinated families of Eucalyptus urophylla from a progeny trial in Vietnam

  Tran Ho Quang, Nguyen Duc Kien, Sara von Arnold, Gunnar Jannson, Ha Huy Thinh, David Clapham
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  ABSTRACT: Lignin and cellulose contents and wood basic density were related to diameter at breast height (DBH) in six fast-growing and five slow-growing families from a combined progeny test and seedling seed orchard of Eucalyptus urophylla grown for 10 years in northern Vietnam. The mean cellulose content of the fast-growing families was significantly higher than that of the slow growing-families (40.0 and 37.1%, respectively), and for individual trees cellulose content was significantly correlated phenotypically with DBH. Wood basic density was significantly lower in the fast-growing group than in the slow-growing group (0.506 and 0.535 g cm-3, respectively), and was significantly negatively correlated phenotypically with DBH. The lignin contents were not significantly different between groups. Cellulose content and wood basic density were not correlated. The main conclusion is that there is no obstacle to combining high growth rate with high cellulose content, for plantation of forests intended mainly for pulpwood.
  New Forests 01/2010; 39(3):301-312. · 1.18 Impact Factor
• Article: The effect of inbreeding on early growth of Acacia mangium in Vietnam

  Harwood C. E, Ha Huy Thinh, Tran Ho Quang, Butcher P. A, Williams E. R
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  ABSTRACT: Seeds were collected from each of twelve parent trees from each of six seed orchards of Acacia mangium in different locations in Vietnam to examine the relationship between growth and inbreeding in this species. Seedlings were raised and planted out in a field trial at Ba Vi in northern Vietnam. The inbreeding status (self-fertilized or outcrossed) of most of the seedlings was determined by DNA analysis. Heights were measured at 12 and 18 months, and diameter at breast height (dbh) at 18 months. There were significant differences in growth between the six orchard sources at 18 months. Progeny from two orchards based primarily on Papua New Guinea (PNG) provenances with high levels of outcrossing displayed the best growth, with mean heights of 3.1 m at 18 months, while an orchard also based primarily on PNG provenances but with predominantly selfed progeny, and another orchard based on Queensland provenances with 51% selfed progeny, displayed the poorest growth (mean heights of 2.0 in and 2.2 in respectively). Analysis of variance established that within the 32 families that included both selfed and outcrossed individuals, self-fertilized individuals were significantly (P < 0.001) slower-growing than were outcrossed individuals, with selfs on average 15 % smaller in mean height and 16 % smaller in mean dbh at age 18 months, relative to outcrosses. The results demonstrate the need to minimise selfing in operational seed production for A. mangium plantations.
  Silvae Genetica. 01/2004; 53(2):65-69.
• Source

  Available from: tuzvo.sk

  Article: Studies of mating systems in seed stands suggest possible causes of variable outcrossing rates in natural populations of Acacia mangium

  Penny Butcher, Chris Harwood, Tran Ho Quang
  Forest Genetics. 01/2004; 11(3-4):303-309.