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Development of an early flowering system for poplar breeding and biosafety research

Trees develop flowers (reproductive phase) only after a longer juvenile phase (vegetative phase), which can last up to 40 years depending on the tree species.One of the most promising approaches in genetic engineering in trees is the transfer of genes to shorten the long vegetative phase.

Background and Objective

Although significant breeding advances have been made in pine, poplar, eucalyptus and some other genera, tree 'cultivars' can still be considered "wild plants".Several successful attempts to induce early flowering in trees have been made using flowering time genes and genes that determine tissue identity.However, the "early flowering" systems available to date for poplars often show disadvantages such as inhibited growth, disturbed pollen development and unexpected effects on other development processes, such as wood formation.This project aims to develop a reliable system for the induction of "early flowering" in poplars.Early flowering trees can both accelerate forest plant breeding and enable the development of strategies to avoid outcrossing of foreign genes in the context of biosafety research.


However, in order to ensure the product range and product quality of forest and fruit trees in the future, the above-mentioned disadvantage could have dramatic economic and labor policy consequences, especially with regard to the predicted climate change, which will probably take place faster than it is possible to adapt trees by breeding.A way out of this dilemma could be the inclusion of early flowering genotypes in the tree breeding process.Such early-flowering lines have either naturally arisen spontaneously as mutants from normally-flowering representatives or can be produced by the genetic transfer of special flowering-promoting genes.

Involved external Thünen-Partners

Funding Body

  • Deutsche Forschungsgemeinschaft (DFG)
    (national, öffentlich)


8.2000 - 10.2022

More Information

Project status: finished


  1. 0

    Fladung M, Hönicka H (2018) Development of an early flowering system for poplar breeding and biosafety research. In: III International PP1530 Symposium: Genetic Variation of Flowering Time Genes and Applications for Crop Improvement : March 14-16, 2018. pp 22-23

  2. 1

    Fladung M, Hönicka H (2016) Forstpflanzenzüchtung auf der Überholspur. AFZ Der Wald 71(14):21-23

  3. 2

    Hönicka H, Lehnhardt D, Nunna S, Reinhardt R, Jeltsch A, Briones V, Fladung M (2016) Level of tissue differentiation influences the activation of a heat-inducible flower-specific system for genetic containment in poplar (Populus tremulaL.). Plant Cell Rep 35(2):369-384, DOI:10.1007/s00299-015-1890-x

  4. 3

    Hönicka H, Lehnhardt D, Briones V, Nilsson O, Fladung M (2016) Low temperatures are required to induce the development of fertile flowers in transgenic male and female early flowering poplar (Populus tremulaL.). Tree Physiol 36(5):667-677, DOI:10.1093/treephys/tpw015

  5. 4

    Bentley AR, Jensen EF, Mackey IJ, Hönicka H, Fladung M, Hori K, Yano M, Mullet JE, Armstead IP, Hayes C, Thorogood D, Lovatt A, Morris R, Pullen N, Mutasa-Göttgens ES, Cockram J (2013) Chapter 1 : Flowering time. In: Kole C (ed) Genomics and breeding for climate-resilient crops : Vol. 2 target traits . Berlin: Springer, pp 1-66

  6. 5

    Hönicka H, Lehnhardt D, Polak O, Fladung M (2012) Early flowering and genetic containment studies in transgenic poplar. iForest 5:138-146, DOI:10.3832/ifor0621-005

  7. 6

    Fladung M, Hanke MV (2012) Induktion einer frühzeitigen Blüte bei Pappel und bei Apfel zur Beschleunigung der Züchtung auf Resistenz gegenüber Krankheiten (SpeedBreed). In: Bundesanstalt für Landwirtschaft und Ernährung (ed) Innovationstage 2012 : Forschungs- und Entwicklungsprojekte ; Programm zur Innovationsförderung des Bundesministeriums für Ernährung, Landwirtschaft und Verbraucherschutz. Bonn: Bundesanstalt für Landwirtschaft und Ernährung, pp 36-40

  8. 7

    Hönicka H, Lautner S, Klingberg A, Koch G, El-Sherif F, Lehnhardt D, Zhang B, Burgert I, Odermatt J, Melzer S, Fromm J, Fladung M (2012) Influence of over-expression of the FLOWERING PROMOTING FACTOR 1 gene (FPF1) from Arabidopsis on wood formation in hybrid poplar (Populus tremula L. x P. tremuloides Michx.). Planta 235(1):359-373

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