Identification of the seasonal conditions required for dormancy break of Persoonia longifolia (Proteaceae), a species with a woody indehiscent endocarp

K.A. Chia, Rohan J. Sadler, Shane R. Turner, C.C. Baskin

    Research output: Contribution to journalArticle

    6 Citations (Scopus)

    Abstract

    © 2016 The Author 2016.Background and Aims The mechanisms involved in breaking seed dormancy in species with woody endocarps are poorly understood. In a landmark study examining the role of endocarps in regulating germination, our aim was to investigate the effects of the natural sequence of environmental conditions on dormancy break of a species with a woody endocarp (Persoonia longifolia). Methods The role of the endocarp in germination was investigated through imbibition and endocarp removal germination tests. The use of burial to break dormancy was examined and results from these experiments were used to guide laboratory investigations into the use of wet/dry cycling and stratification to break dormancy. Key Results Endocarps were water-permeable. Germination increased from 0 to 92·5 % when endocarps were removed. During burial in the field and nursery, 41·6 and 63·7 % of the endocarps germinated, respectively, after 36 months. Ex situ post-burial germination was cyclical and highest after 30 months of burial (45·4 % nursery and 31·8 % field). Highest germination occurred in wet/dry trials when the dry summer was long (20 weeks), had fluctuating temperatures (30/50 °C) and two long (7 d) wet cycles and was followed by moist winters at 10/20 °C. A stratification trial found that highest germination occurred following incubation for 12 weeks at 30 °C (including 2 weeks moist) + 6 weeks moist at 8 °C then placement at 20/10 °C for germination. Conclusions Summer conditions break physiological dormancy of the embryo and promote opening of the endocarp, allowing seeds to germinate during winter conditions. By closely monitoring the environment that endocarps are exposed to in nature, dormancy breaking mechanisms can be identified and used to improve germination. These results outline for the first time how dormancy and germination are regulated in a species with a hard woody endocarp, insights which will significantly improve our understanding of other species with similar reproductive features.
    Original languageEnglish
    Pages (from-to)331-346
    Number of pages16
    JournalAnnals of Botany
    Volume118
    Issue number2
    DOIs
    Publication statusPublished - 2016

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    endocarp
    Proteaceae
    dormancy
    germination
    seed stratification
    Persoonia
    dormancy breaking
    winter
    environmental monitoring
    summer
    seed dormancy
    imbibition
    embryo (plant)

    Cite this

    @article{04d417496c344737a6646aa1756f4c66,
    title = "Identification of the seasonal conditions required for dormancy break of Persoonia longifolia (Proteaceae), a species with a woody indehiscent endocarp",
    abstract = "{\circledC} 2016 The Author 2016.Background and Aims The mechanisms involved in breaking seed dormancy in species with woody endocarps are poorly understood. In a landmark study examining the role of endocarps in regulating germination, our aim was to investigate the effects of the natural sequence of environmental conditions on dormancy break of a species with a woody endocarp (Persoonia longifolia). Methods The role of the endocarp in germination was investigated through imbibition and endocarp removal germination tests. The use of burial to break dormancy was examined and results from these experiments were used to guide laboratory investigations into the use of wet/dry cycling and stratification to break dormancy. Key Results Endocarps were water-permeable. Germination increased from 0 to 92·5 {\%} when endocarps were removed. During burial in the field and nursery, 41·6 and 63·7 {\%} of the endocarps germinated, respectively, after 36 months. Ex situ post-burial germination was cyclical and highest after 30 months of burial (45·4 {\%} nursery and 31·8 {\%} field). Highest germination occurred in wet/dry trials when the dry summer was long (20 weeks), had fluctuating temperatures (30/50 °C) and two long (7 d) wet cycles and was followed by moist winters at 10/20 °C. A stratification trial found that highest germination occurred following incubation for 12 weeks at 30 °C (including 2 weeks moist) + 6 weeks moist at 8 °C then placement at 20/10 °C for germination. Conclusions Summer conditions break physiological dormancy of the embryo and promote opening of the endocarp, allowing seeds to germinate during winter conditions. By closely monitoring the environment that endocarps are exposed to in nature, dormancy breaking mechanisms can be identified and used to improve germination. These results outline for the first time how dormancy and germination are regulated in a species with a hard woody endocarp, insights which will significantly improve our understanding of other species with similar reproductive features.",
    author = "K.A. Chia and Sadler, {Rohan J.} and Turner, {Shane R.} and C.C. Baskin",
    year = "2016",
    doi = "10.1093/aob/mcw100",
    language = "English",
    volume = "118",
    pages = "331--346",
    journal = "Annals of Botany",
    issn = "0305-7364",
    publisher = "OXFORD UNIV PRESS UNITED KINGDOM",
    number = "2",

    }

    Identification of the seasonal conditions required for dormancy break of Persoonia longifolia (Proteaceae), a species with a woody indehiscent endocarp. / Chia, K.A.; Sadler, Rohan J.; Turner, Shane R.; Baskin, C.C.

    In: Annals of Botany, Vol. 118, No. 2, 2016, p. 331-346.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Identification of the seasonal conditions required for dormancy break of Persoonia longifolia (Proteaceae), a species with a woody indehiscent endocarp

    AU - Chia, K.A.

    AU - Sadler, Rohan J.

    AU - Turner, Shane R.

    AU - Baskin, C.C.

    PY - 2016

    Y1 - 2016

    N2 - © 2016 The Author 2016.Background and Aims The mechanisms involved in breaking seed dormancy in species with woody endocarps are poorly understood. In a landmark study examining the role of endocarps in regulating germination, our aim was to investigate the effects of the natural sequence of environmental conditions on dormancy break of a species with a woody endocarp (Persoonia longifolia). Methods The role of the endocarp in germination was investigated through imbibition and endocarp removal germination tests. The use of burial to break dormancy was examined and results from these experiments were used to guide laboratory investigations into the use of wet/dry cycling and stratification to break dormancy. Key Results Endocarps were water-permeable. Germination increased from 0 to 92·5 % when endocarps were removed. During burial in the field and nursery, 41·6 and 63·7 % of the endocarps germinated, respectively, after 36 months. Ex situ post-burial germination was cyclical and highest after 30 months of burial (45·4 % nursery and 31·8 % field). Highest germination occurred in wet/dry trials when the dry summer was long (20 weeks), had fluctuating temperatures (30/50 °C) and two long (7 d) wet cycles and was followed by moist winters at 10/20 °C. A stratification trial found that highest germination occurred following incubation for 12 weeks at 30 °C (including 2 weeks moist) + 6 weeks moist at 8 °C then placement at 20/10 °C for germination. Conclusions Summer conditions break physiological dormancy of the embryo and promote opening of the endocarp, allowing seeds to germinate during winter conditions. By closely monitoring the environment that endocarps are exposed to in nature, dormancy breaking mechanisms can be identified and used to improve germination. These results outline for the first time how dormancy and germination are regulated in a species with a hard woody endocarp, insights which will significantly improve our understanding of other species with similar reproductive features.

    AB - © 2016 The Author 2016.Background and Aims The mechanisms involved in breaking seed dormancy in species with woody endocarps are poorly understood. In a landmark study examining the role of endocarps in regulating germination, our aim was to investigate the effects of the natural sequence of environmental conditions on dormancy break of a species with a woody endocarp (Persoonia longifolia). Methods The role of the endocarp in germination was investigated through imbibition and endocarp removal germination tests. The use of burial to break dormancy was examined and results from these experiments were used to guide laboratory investigations into the use of wet/dry cycling and stratification to break dormancy. Key Results Endocarps were water-permeable. Germination increased from 0 to 92·5 % when endocarps were removed. During burial in the field and nursery, 41·6 and 63·7 % of the endocarps germinated, respectively, after 36 months. Ex situ post-burial germination was cyclical and highest after 30 months of burial (45·4 % nursery and 31·8 % field). Highest germination occurred in wet/dry trials when the dry summer was long (20 weeks), had fluctuating temperatures (30/50 °C) and two long (7 d) wet cycles and was followed by moist winters at 10/20 °C. A stratification trial found that highest germination occurred following incubation for 12 weeks at 30 °C (including 2 weeks moist) + 6 weeks moist at 8 °C then placement at 20/10 °C for germination. Conclusions Summer conditions break physiological dormancy of the embryo and promote opening of the endocarp, allowing seeds to germinate during winter conditions. By closely monitoring the environment that endocarps are exposed to in nature, dormancy breaking mechanisms can be identified and used to improve germination. These results outline for the first time how dormancy and germination are regulated in a species with a hard woody endocarp, insights which will significantly improve our understanding of other species with similar reproductive features.

    U2 - 10.1093/aob/mcw100

    DO - 10.1093/aob/mcw100

    M3 - Article

    VL - 118

    SP - 331

    EP - 346

    JO - Annals of Botany

    JF - Annals of Botany

    SN - 0305-7364

    IS - 2

    ER -