Trembling aspen ( Populus tremuloides Michx.) is one of the most abundant poplar species in North America; it is native, displays substantial breadth in distribution inhabiting several geographical and climatic ecoregions, is notable for its rapid growth, and is ecologically and economically important. As the demand for raw material continues to increase rapidly, there is a pressing need to improve both tree quality and growth rates via breeding efforts. Hybridization is considered one of the most promising options to simultaneously accelerate these tree characteristics, as it takes advantage of heterosis. Two aspen species showing particular promise for hybridization with trembling aspen are European aspen ( P. tremula) and Chinese aspen ( P. davidiana) because their native climates are similar to that of P. tremuloides and are also very easy to hybridize. In 2003, aspen clones were planted in Athabasca, Alberta from the following species crosses: open pollinated (OP) P. tremuloides (NN), OP P. davidiana (CC), P. tremula × P. tremula (EE), P. tremula × P. tremuloides (EN), and P. tremuloides × P. davidiana (CN). In November 2010, growth measurements and core samples were taken from seven-year field grown clones. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. The results clearly indicated that the inter-specific crosses offer a means to breed for more desirable wood characteristics than the intra-specific Populus spp. crosses.
References
[1]
Zsuffa, L.E.; Giordano, L.D.; Stettler, R.F. Trends in poplar culture: Some global and regional perspectives. In Biology of Populus and Its Implications for Management and Conservation; Stettler, R.F., Bradshaw, H.D., Heilman, P.E., Hinckley, T.M., Eds.; NRC Research Press: Ottawa, Canada, 1996; pp. 515–539.
[2]
Peterson, E.B.; Peterson, N.M. Aspen [Populus tremuloides] managers’ handbook for British Columbia. FRDA Rep. Vic.BC 1995, 230, 1–36.
[3]
Einspahr, D.W.; Wyckoff, G.W. North American aspen: Timber supply, utilization, and researc. North. J. Appl. For. 1990, 7, 168–171.
[4]
Einspahr, D.W.; Benson, M.K. Fiber and pulp properties of triploid and triploid hybrid aspen. Tappi J. 1970, 53, 1853–1856.
[5]
Peterson, E.B.; Peterson, N.M. Ecology, management, and use of aspen and balsam poplar in the prairie provinces, Canada. Can. For. Service 1992, 1, 252.
[6]
Cisneros, N.; Belanger, L.; Gee, W.Y.; Watson, P.A.; Hatton, J.V. Wood and fiber properties of hybrid poplars from Southern British Columbia. Tappi. Proc. 2000, 83, 60.
[7]
Ondro, W.J. Utilization and Market Potential of Poplar in Alberta; Northern Forestry Centre, Forestry Canada: Edmonton, Canada, 1989; pp. 271–274.
[8]
Mansfield, S.D. Solutions for dissolution—Engineering cell walls for deconstruction. Curr. Opin.Biotechnol. 2009, 20, 286–294, doi:10.1016/j.copbio.2009.05.001.
[9]
Einspahr, D.W. Production and utilization of triploid hybrid aspen. Iowa State J. Resour. 1984, 58, 401–409.
[10]
Zsuffa, L. A summary review of interspecific breeding in the genus Populus L. In Proceedings of the 14th meeting of the Canadian Tree Improvement Association, Part 2, Fredericton, New Brunswick, Canada, 28–30 August 1973; pp. 107–123.
[11]
Einspahr, D.W.; Winton, L.L. Genetics of quaking aspen. Aspen Bibliogr. 1976, Paper No. 5026, 1–23.
[12]
Li, B.; Wyckoff, G.W.; Einspahr, D.W. Hybrid aspen performance and genetic gains. North. J. Appl. For. 1993, 10, 117–122.
[13]
Melchior, G.H. Breeding of aspen and hybrid aspen and their importance for practical use. Allg. For. und Jagdztg. 1985, 156, 112–122.
[14]
Kailong, L.; Fangchun, Z.; Guorong, B.; Jia, S. Research advances in genetics and breeding of Populus davidiana Dode in China. J. For. Res. 1999, 10, 25–30, doi:10.1007/BF02855474.
[15]
Yu, Q.; Tigerstedt, P.M.A.; Haapanen, M. Growth and phenology of hybrid aspen clones (Populustremula L. × Populus tremuloides Michx.). Silv. Fenn. 2001, 35, 15–25.
[16]
Tullus, A.; Rytter, L.; Tullus, T.; Weih, M.; Tullus, H. Short-rotation forestry with hybrid aspen (Populus tremula L. × P. tremuloides Michx.) in Northern Europe. Scand. J. For. Res. 2012, 27, 10–29, doi:10.1080/02827581.2011.628949.
[17]
Aziz, S.; Wyckoff, G.W.; Wyckoff, J.L. Wood and Pulp Properties of Aspen and Its Hybrids,1996 Pulping Conference Proceedings, Tappi, Norcross, GA, USA; 1996; pp. 437–444.
[18]
Farmer, R.E. Genetic-improvement of poplar in Western Canada-alternatives, opportunities, and pitfalls. In Aspen Management for the 21st Century; Navratil, S., Chapman, P.B., Eds.; Forestry Canada, Northwest Region and Poplar Council of Canada: Edmonton, Alberta, Canada, 1991; p. 174.
[19]
Li, B. Aspen improvement strategies for Western Canada-Alberta and Saskatchewan. For. Chron. 1995, 71, 720–724.
[20]
Heimburger, C. Report on poplar hybridization. For. Chron. 1936, 12, 285–290.
[21]
Stettler, R.F.; Fenn, R.C.; Heilman, P.E.; Stanton, B.J. Populus trichocarpa × Populus deltoides hybrids for short rotation culture: Variation patterns and 4-year field performance. Can. J. For. Res. 1988, 18, 745–753, doi:10.1139/x88-114.
[22]
Wu, R.L.; Wang, M.X.; Huang, M.R. Quantitative genetics of yield breeding for Populus short rotation culture. I. Dynamics of genetic control and selection model of yield traits. Can. J. For. Res. 1992, 22, 175–182, doi:10.1139/x92-023.
[23]
Falconer, D.S. Introduction to Quantitative Genetics; Longman Scientific and Technical: London, UK, 1989; Volume 3.
[24]
Baranwal, V.K.; Mikkilineni, V.; Zehr, U.B.; Tyagi, A.K.; Kapoor, S. Heterosis: Emerging ideas about hybrid vigour. J. Exp. Bot. 2012, 63, 6309–6314, doi:10.1093/jxb/ers291.
[25]
Li, B.; Wu, R. Genetic causes of heterosis in juvenile aspen: A quantitative comparison across intra- and inter-specific hybrids. Theor. Appl. Genet. 1996, 93, 380–391, doi:10.1007/BF00223180.
[26]
Li, B.; Howe, G.T.; Wu, R. Developmental factors responsible for heterosis in aspen hybrids (Populus tremuloides × P. tremula). Tree Physiol. 1998, 18, 37–43, doi:10.1093/treephys/18.1.37.
[27]
British Columbia Forest Inventory Division. Whole Stem Cubic Metre Volume Equations and Tables:Centimetre Diameter Class Merchantable Volume Factors; Forest Inventory Division, British Columbia Forest Service, Department of Forests: Victoria, British Columbia, Canada, 1976.
[28]
Robinson, A.R.; Mansfield, S.D. Rapid analysis of poplar lignin monomer composition by a streamlined thioacidolysis procedure and near-infrared reflectance-based prediction modeling. Plant J. 2009, 58, 706–714, doi:10.1111/j.1365-313X.2009.03808.x.
[29]
Junkkonen, R.; Her？j？rvi, H. Physical Properties of European and Hybrid Aspen Wood after Three Different Drying Treatments. In Proceedings of the 5th International Symposium of Wood Structure and Properties, Zvolen, Slovakia, 3–6 September 2006; pp. 257–263.
[30]
Bjurhager, I.; Berglund, L.A.; Bardage, S.L.; Sundberg, B. Mechanical characterization of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × Populus tremuloides) using full-field strain measurements. J. Wood Sci. 2008, 54, 349–355, doi:10.1007/s10086-008-0960-x.
[31]
K？rki, T. Variation of wood density and shrinkage in European aspen (Populus tremula). Eur. J. Wood Wood Prod. 2001, 59, 79–84, doi:10.1007/s001070050479.
[32]
Yanchuk, A.; Dancik, B.; Micko, M. Intraclonal variation in wood density of trembling aspen in Alberta. Wood Fiber Sci. 1983, 15, 387–394.
[33]
Tsoumis, G. Science and Technology of Wood. Structure, Properties, Utilization; Van Nostrand Reinhold: New York, NY, USA, 1991; pp. xiii–494.
[34]
Yanchuk, A.; Micko, M. Radial variation of wood density and fibre length in trembling aspen. IAWA Bull. 1990, 11, 211–215.
Maloney, V.J.; Mansfield, S.D. Characterization and varied expression of a membrane-bound endo-β-1,4-glucanase in hybrid poplar. Plant Biotechnol. J. 2010, 8, 294–307, doi:10.1111/j.1467-7652.2009.00483.x.
[37]
Barnett, J.R.; Bonham, V.A. Cellulose microfibril angle in the cell wall of wood fibres. Biolog. Rev. 2004, 79, 461–472, doi:10.1017/S1464793103006377.
[38]
Fang, S.; Yang, W.; Tian, Y. Clonal and within-tree variation in microfibril angle in poplar clones. New For. 2006, 31, 373–383, doi:10.1007/s11056-005-8679-7.
[39]
Francis, R.C.; Hanna, R.B.; Shin, S.J.; Brown, A.F.; Riemenschneider, D.E. Papermaking characteristics of three Populus clones grown in the North-Central United States. Biomass Bioenerg. 2006, 30, 803–808, doi:10.1016/j.biombioe.2005.08.003.
[40]
Groover, A.T.; Nieminen, K.; Helariutta, Y.; Mansfield, S.D. Wood formation in Populus. Genet. Genomics Populus 2010, 8, 201–224.
[41]
Yanchuk, A.D.; Dancik, B.P.; Micko, M.M. Variation and heritability of wood density and fiber length of trembling aspen in Alberta, Canada. Silvae Genet. 1984, 33, 11–16.
[42]
Amidon, T.E. Effect of the wood properties of hardwoods on Kraft paper properties. Tappi J. 1981, 64, 123–126.
[43]
Horn, R.A. Morphology of Pulp Fiber from Hardwoods and Influence on Paper Strength; Forest Products Lab: Madison, WI, USA, 1978; pp. 1–9.
[44]
Paavilainen, L. Conformability, flexibility and collapsibility of sulphate pulp fibres. Paperi ja puu 1993, 75, 689–702.
[45]
Via, B.K.; Stine, M.; Shupe, T.F.; So, C.L.; Groom, L. Genetic improvement of fiber length and coarseness based on paper product performance and material variability: A review. IAWA J. 2004, 25, 401–414, doi:10.1163/22941932-90000373.
[46]
Karaim, B.W.; Wengert, E.M.; Szabo, T.; Adams, R.D. Opportunities for aspen and balsam poplar utilization in Alberta. Aspen Bibliogr. 1990, Paper No. 2929, 1–27.
[47]
Mansfield, S.D.; Weineisen, H. Wood fiber quality and Kraft pulping efficiencies of trembling aspen (Populus tremuloides Michx.) clones. J. Wood Chem. Technol. 2007, 27, 135–151, doi:10.1080/02773810701700786.
[48]
Stewart, J.J.; Kadla, J.F.; Mansfield, S.D. The influence of lignin chemistry and ultrastructure on the pulping efficiency of clonal aspen (Populus tremuloides Michx.). Holzforschung 2006, 60, 111–122.
[49]
Chang, H.M.; Sarkanen, K.V. Species variation in lignin: Effects of species on the rate of Kraft delignification. Tappi J. 1973, 56, 132–134.
[50]
Mansfield, S.D.; Kang, K.Y.; Chapple, C. Designed for deconstruction-poplar trees altered in cell wall lignification improve the efficacy of bioethanol production. New Phytol. 2012, 194, 91–101, doi:10.1111/j.1469-8137.2011.04031.x.
[51]
Pettersen, R.C. The chemical composition of wood. Chem. Solid Wood 1984, 57–126, doi:10.1021/ba-1984-0207.ch002.
[52]
Rowell, R.M. Handbook of Wood Chemistry and Wood Composites; CRC Press LLC: Boca Raton, FL, USA, 2005; pp. 1–659.
[53]
Mansfield, S.D.; Mooney, C.; Saddler, J.N. Substrate and enzyme characteristics that limit cellulose hydrolysis. Biotechnol. Prog. 1999, 15, 804, doi:10.1021/bp9900864.
[54]
Baucher, M.; Halpin, C.; Petit-Conil, M.; Boerjan, W. Lignin: Genetic engineering and impact on pulping. Crit. Rev. Biochem. Mole. Biol. 2003, 38, 305–350, doi:10.1080/10409230391036757.
[55]
Ukrainetz, N.K.; Kang, Y.K.; Aitken, S.N.; Stoehr, M.; Mansfield, S.D. Heritability and phenotypic and genetic correlations of coastal Douglas-fir (Pseudotsuga menziesii) wood quality traits. Can. J. For. Res. 2008, 38, 1536–1546, doi:10.1139/X07-234.
[56]
Gerendiain, A.Z.; Peltola, H.; Pulkkinen, P.; Jaatinen, R.; Pappinen, A. Differences in fibre properties in cloned Norway spruce (Picea abies). Can. J. For. Res. 2008, 38, 1071–1082, doi:10.1139/X07-220.
[57]
Kibblewhite, R.P.; Uprichard, J.M. Kraft pulp qualities of eleven radiata pine clones. Appita J. 1996, 49, 243–250.
[58]
Bose, S.K.; Francis, R.C.; Govender, M.; Bush, T.; Spark, A. Lignin content versus syringyl to guaiacyl ratio amongst poplars. Bioresour. Technol. 2009, 100, 1628–1633, doi:10.1016/j.biortech.2008.08.046.
[59]
Del Río, J.C.; Gutiérrez, A.; Hernando, M.; Landín, P.; Romero, J.; Martínez, á.T. Determining the influence of eucalypt lignin composition in paper pulp yield using Py-GC/MS. J. Anal. Appl. Pyrolysis 2005, 74, 110–115, doi:10.1016/j.jaap.2004.10.010.
[60]
Porth, I.; Kláp？tě, J.; Skyba, O.; Lai, B.S.K.; Geraldes, A.; Muchero, W.; Tuskan, G.A.; Douglas, C.J.; El-Kassaby, Y.A.; Mansfield, S.D. Populus trichocarpa cell wall chemistry and ultrastructure trait variation, genetic control and genetic correlations. New Phytol. 2013, 197, 777–790, doi:10.1111/nph.12014.
