Apiaceae morphological dormancy and germination differ between crop and wild species, and among crop cultivars in the mechanical, hormonal and thermal mechanisms that control pericarp (fruit coat) weakening and pre-gremination embryo growth. The Apiaceae disperse morphologically (MD) or morphophysiologically dormant mericarps, indehicent fruits in which the single seed is encased by the pericarp (fruit coat) and the underdeveloped (small) embryo is embedded in abundant living endosperm tissue. Pre-germination embryo growth from an initial to a critical relative embryo size (embryo:fruit or embryo:seed length ratio) is a requirement for the completion of germination by radicle emergence. The roles and mechanisms of pre-gremination embryo growth and pericarp constraint were investigated by embryo-growth imaging, pericarp ablation/biomechanics, tissue-specific hormone analytics, and population-based thermal-time threshold modelling. Comparison of Apiaceae crop cultivars, including Pastinaca sativa (parsnip), Apium graveolens (celery) and Daucus carota (carrot) with > 50 wild Apiaceae species revealed that the initial relative embryo sizes of crop species are significantly larger compared to wild species. Interestingly, the critical relative embryo sizes of the phylogenetic group that contains parsnip, were smaller for the crop compared to wild species. ABA-insensitive and auxin-promoted pre-germination embryo growth was blocked by heat (thermoinhibition), while the completion of germination by radicle emergence was inhibited by ABA. The thick pericarp of parsnip decreased in thickness and mechanical tissue resistance in parallel with the pre-germination embryo growth, while the thin pericarps of celery and carrot did not change. Parsnip pericarp contained significantly higher contents of the germination-inhibiting hormones abscisic acid (ABA) and cis-(+)-12-oxo-phytodienoic acid (cis-OPDA) compared to celery pericarp. Pericarp ablation experiments revealed that it acts as a mechanical and chemical (ABA, cis-OPDA) constraint (coat component of MD), and has a key role in narrowing the permissive temperature window for germination.

Department of Agro Environmental Science Obihiro University of Agriculture and Veterinary Medicine Obihiro Hokkaido 080 8555 Japan

Department of Biological Sciences Royal Holloway University of London Egham Surrey TW20 0EX UK

Eden Research Plc Milton Park Oxfordshire OX14 4SA UK

Elsoms Seeds Ltd Spalding Lincolnshire PE11 1QG UK

Laboratory of Growth Regulators Institute of Experimental Botany Palacký University Olomouc Czech Academy of Sciences and Faculty of Science 77900 Olomouc Czech Republic

Tozer Seeds Ltd Cobham Surrey KT11 3EH UK

Zobrazit více v PubMed

Atia A, Debez A, Barhoumi Z, Pacini E, Abdelly C, Smaoui A (2010) The mericarp of the halophyte

Biddington NL, Thomas TH (1978) Thermodormancy in celery seeds and its removal by cytokinins and gibberellins. Physiol Plant 42:401–405. 10.1111/j.1399-3054.1978.tb04104.x

Baskin JM, Baskin CM (1979) Studies on the autecology and population biology of the weedy monocarpic perennial,

Baskin JM, Baskin CC (1990a) Germination ecophysiology of seeds of the winter annual

Baskin JM, Baskin CC (1990b) Seed germination ecology of poison hemlock,

Baskin JM, Baskin CC (1991) Nondeep complex morphophysiological dormancy in seeds of

Burmeier S, Jensen K (2008) Is the endangered

Baskin CC, Baskin JM (2014) Seeds—ecology, biogeography, and evolution of dormancy and germination. Academic Press, San Diego, London

Batlla D, Benech-Arnold RL (2015) A framework for the interpretation of temperature effects on dormancy and germination in seed populations showing dormancy. Seed Sci Res 25:147–158. 10.1017/S0960258514000452

Baskin JM, Baskin CC (2021) The great diversity in kinds of seed dormancy: a revision of the Nikolaeva-Baskin classification system for primary seed dormancy. Seed Sci Res 31:249–277. 10.1017/S096025852100026x

Bradford KJ, Bello P (2022) Applying population-based threshold models to quantify and improve seed quality attributes. In: Buitink J, Leprince O (eds) Advances in seed science and technology for more sustainable crop production. Burleigh Dodds Science Publishing, Cambridge, pp 67–154. 10.19103/AS.2022.0105.05

Baskin CC, Meyer SE, Baskin JM (1995) Two types of morphophysiological dormancy in seeds of two genera (

Baskin CC, Milberg P, Andersson L, Baskin JM (2000) Deep complex morphophysiological dormancy in seeds of

Brown LA, Larson TR, Graham IA, Hawes C, Paudyal R, Warriner SL, Baker A (2013) An inhibitor of oil body mobilization in Arabidopsis. New Phytol 200:641–649. 10.1111/nph.12467 PubMed

Blandino C, Fernandez-Pascual E, Marin M, Vernet A, Pritchard HW (2019) Seed ecology of the geophyte PubMed PMC

Bukharov AF, Baleev DN, Soldatenko AV, Musaev FB, Kezimana P, Priyatkin NS (2021) Impacts of high temperature on embryonic growth and seed germination of dill (

Blandino C, Natlandsmyr B, Sandvik SM, Pritchard HW, Fernandez-Pascual E (2025) Functional biogeography of the thermal thresholds for post-dispersal embryo growth in PubMed PMC

Corbineau F, Picard MA, Bonnet A, Come D (1995) Effects of production factors on germination responses of carrot seeds to temperature and oxygen. Seed Sci Res 5:129–135. 10.1017/S0960258500002749

Coumans M, Come D, Gaspar T (1976) Stabilized dormancy in sugarbeet fruits. I. Seed coats as a physicochemical barrier to oxygen. Bot Gaz 137:274–278. 10.1086/336870

Cousens RD, Young KR, Tadayyon A (2010) The role of the persistent fruit wall in seed water regulation in PubMed PMC

Chahtane H, Kim W, Lopez-Molina L (2017) Primary seed dormancy: a temporally multilayered riddle waiting to be unlocked. J Exp Bot 68:857–869. 10.1093/jxb/erw377 PubMed

Cho JS, Jang BK, Lee CH (2018) Seed dormancy and germination characteristics of the endangered species

Carta A, Vandelook F, Ramirez-Barahona S, Chen SC, Dickie J, Steinbrecher T, Thanos CA, Moles AT, Leubner-Metzger G, Mattana E (2024) The seed morphospace, a new contribution towards the multidimensional study of angiosperm sexual reproductive biology. Ann Bot 134:701–710. 10.1093/aob/mcae099 PubMed PMC

Chandler JO, Wilhelmsson PKI, Fernandez-Pozo N, Graeber K, Arshad W, Pérez M, Steinbrecher T, Ullrich KK, Nguyen T-P, Mérai Z, Mummenhoff K, Theißen G, Strnad M, Mittelsten Scheid O, Schranz ME, Petřík I, Tarkowská D, Novák O, Rensing SA, Leubner-Metzger G (2024) The dimorphic diaspore model PubMed PMC

Dave A, Vaistij FE, Gilday AD, Penfield SD, Graham IA (2016) Regulation of PubMed PMC

de Miranda RM, Dias DCFD, Picoli EAD, da Silva PP, Nascimento WM (2017) Physiological quality, anatomy and histochemistry during the development of carrot seeds (

Del Bel ZD, Andrade A, Maddalena MD, Vigliocco A, Alemano S (2023) The interplay of specific hormonal profile in fruit parts of sunflower inbred lines with contrasting dormancy levels during germination and dormancy breaking by exogenous application of plant growth regulators. Crop Sci 63:852–866. 10.1002/csc2.20912

Finch-Savage WE, Footitt S (2017) Seed dormancy cycling and the regulation of dormancy mechanisms to time germination in variable field environments. J Exp Bot 68:843–856. 10.1093/jxb/erw477 PubMed

Fasih M, Afshari RT (2018) The morphophysiological dormancy of

Finch-Savage WE, Steckel JRA, Phelps K (1998) Germination and post-germination growth to carrot seedling emergence: predictive threshold models and sources of variation between sowing occasions. New Phytol 139:505–516. 10.1046/j.1469-8137.1998.00208.x

Finch-Savage WE, Leubner-Metzger G (2006) Seed dormancy and the control of germination. New Phytol 171:501–523. 10.1111/j.1469-8137.2006.01787.x PubMed

Flokova K, Tarkowska D, Miersch O, Strnad M, Wasternack C, Novak O (2014) Uhplc-ms/ms based target profiling of stress-induced phytohormones. Phytochemistry 105:147–157. 10.1016/j.phytochem.2014.05.015 PubMed

Hassell RL, Kretchman DW (1997) The effects of umbel order, soaking, and scarification on germination inhibiting substances in

Hendrix SD, Nielsen E, Nielsen T, Schutt M (1991) Are seedlings from small seeds always inferior to seedlings from large seeds? Effects of seed biomass on seedling growth in PubMed

Hermann K, Meinhard J, Dobrev P, Linkies A, Pesek B, Heß B, Machackova I, Fischer U, Leubner-Metzger G (2007) 1-aminocyclopropane-1-carboxylic acid and abscisic acid during the germination of sugar beet ( PubMed

Hawkins TS, Baskin CC, Baskin JM (2010) Morphophysiological dormancy in seeds of three eastern North American

Homrichhausen TM, Hewitt JR, Nonogaki H (2003) Endo-ß-mannanase activity is associated with the completion of embryogenesis in imbibed carrot (

Hourston JE, Steinbrecher T, Chandler JO, Pérez M, Dietrich K, Turečková V, Tarkowská D, Strnad M, Weltmeier F, Meinhard J, Fischer U, Fiedler-Wiechers K, Ignatz M, Leubner-Metzger G (2022) Cold-induced secondary dormancy and its regulatory mechanisms in PubMed PMC

Hashemirad S, Soltani E, Darbandi AI, Alahdadi I (2023) Cold stratification requirement to break morphophysiological dormancy of fennel (

Ignatz M, Hourston JE, Tureckova V, Strnad M, Meinhard J, Fischer U, Steinbrecher T, Leubner-Metzger G (2019) The biochemistry underpinning industrial seed technology and mechanical processing of sugar beet. Planta 250:1717–1729. 10.1007/s00425-019-03257-5 PubMed PMC

Jacobsen JV, Pressman E, Pyliotis NA (1976) Gibberellin-induced separation of cells in isolated endosperm of celery seed. Planta 129:113–122. 10.1007/BF00390017 PubMed

Jacobsen JV, Pressman E (1979) A structural study of germination in celery ( PubMed

Kim YH, Janick J (1991) Abscisic acid and proline improve desiccation tolerance and increase fatty acid content of celery somatic embryos. Plant Cell Tissue Organ Cult 24:83–89. 10.1007/Bf00039735

Kadluczka D, Grzebelus E (2022) Comparative fruit morphology and anatomy of wild relatives of carrot (

Koryzniene D, Jurkoniene S, Zalnierius T, Gaveliene V, Jankovska-Bortkevic E, Bareikiene N, Buda V (2019) PubMed PMC

Linkies A, Leubner-Metzger G (2012) Beyond gibberellins and abscisic acid: how ethylene and jasmonates control seed germination. Plant Cell Rep 31:253–270. 10.1007/s00299-011-1180-1 PubMed

Liu M, Plunkett GM, Lowry PP, Van Wyk BE, Tilney PM (2006) The taxonomic value of fruit wing types in the order Apiales. Am J Bot 93:1357–1368. 10.3732/ajb.93.9.1357 PubMed

Liu M, Plunkett GM, Van Wyk BE, Tilney PM, Lowry PP (2012) The phylogenetic significance of the carpophore in Apiaceae. Ann Bot 110:1531–1543. 10.1093/aob/mcs204 PubMed PMC

Liu XD, Zhang H, Zhao Y, Feng ZY, Li Q, Yang HQ, Luan S, Li JM, He ZH (2013) Auxin controls seed dormancy through stimulation of abscisic acid signaling by inducing ARF-mediated ABI3 activation in PubMed PMC

Loades E, Perez M, Tureckova V, Tarkowska D, Strnad M, Seville A, Nakabayashi K, Leubner-Metzger G (2023) Distinct hormonal and morphological control of dormancy and germination in PubMed PMC

Matilla AJ (2020) Auxin: hormonal signal required for seed development and dormancy. Plants 9:705. 10.3390/plants9060705 PubMed PMC

Mamut J, Tan D-Y, Baskin CC, Baskin JM (2014) Role of trichomes and pericarp in the seed biology of the desert annual

Ma XD, Mao WW, Zhou P, Li P, Li HJ (2015) Distinguishing PubMed

Mohammed S, Turckova V, Tarkowska D, Strnad M, Mummenhoff K, Leubner-Metzger G (2019) Pericarp-mediated chemical dormancy controls the fruit germination of the invasive hoary cress (

Mustafina FU, Lee H, Sharipova VK, Lee A, Kim DW, Choi MN, Jang JW, Kim YS (2021) Comparative fruit morphology and its systematic significance in

Mohammadianfar E, Ghaderi-Far F, Torabi B, Siahmarguee A, Behroj M, Baskin C, Sadeghipour HR (2024) Variation in degree of intermediate complex morphophysiological dormancy in seeds of

Nakabayashi K, Walker M, Irwin D, Cohn J, Gurda S, Garcia L, Pavlovic I, Novak O, Tarkowska D, Strnad M, Perez M, Seville A, Stock D, Leubner-Metzger G (2022) The phytotoxin myrigalone A triggers a phased detoxification programme and inhibits PubMed PMC

Nascimento WM, Huber DJ, Cantliffe DJ (2013) Carrot seed germination and ethylene production at high temperature in response to seed osmopriming. Hortic Bras 31:554–558. 10.1590/S0102-05362013000400008

Noor A, Ziaf K, Amjad M, Ahmad I (2020) Synthetic auxins concentration and application time modulates seed yield and quality of carrot by altering the umbel order. Sci Hortic-Amsterdam 262:109066. 10.1016/j.scienta.2019.109066

Olszewski MW, Pill WG, Pizzolato TD (2004) Germination and embryo anatomy of osmotically primed parsley schizocarps. J Am Soc Hortic Sci 129:876–880. 10.21273/Jashs.129.6.0876

Olszewski M, Pill W, Pizzolato TD, Pesek J (2005) Priming duration influences anatomy and germination responses of parsley mericarps. J Am Soc Hortic Sci 130:754–758. 10.21273/Jashs.130.5.754

Önder S, Periz CD, Ulusoy S, Erbas S, Önder D, Tonguc M (2024) Chemical composition and biological activities of essential oils of seven cultivated Apiaceae species. Sci Rep 14:10052. 10.1038/s41598-024-60810-3 PubMed PMC

Phartyal SS, Kondo T, Baskin JM, Baskin CC (2009) Temperature requirements differ for the two stages of seed dormancy break in PubMed

Porceddu M, Mattana E, Pritchard HW, Bacchetta G (2017) Dissecting seed dormancy and germination in PubMed

Pellizzaro A, Neveu M, Lalanne D, Vu BL, Kanno Y, Seo M, Leprince O, Buitink J (2020) A role for auxin signaling in the acquisition of longevity during seed maturation. New Phytol 225:284–296. 10.1111/nph.16150 PubMed

Pan J, Wang H, You Q, Cao R, Sun G, Yu D (2023) Jasmonate-regulated seed germination and crosstalk with other phytohormones. J Exp Bot 74:1162–1175. 10.1093/jxb/erac440 PubMed

Robinson RW (1954) Seed germination problems in the Umbelliferae. Bot Rev 20:531–550. 10.1007/BF02958802

Richard G, Raymond P, Corbineau F, Pradet A (1989) Effect of the pericarp on sugar beet (

Rahimi H, Rezanejad F, Ayatollahi SA, Sharifi-Sirchi GR, Rahimi H (2024) Embryo growth and seed germination requirements in underdeveloped embryos of

Steinbrecher T, Leubner-Metzger G (2017) The biomechanics of seed germination. J Exp Bot 68:765–783. 10.1093/jxb/erw428 PubMed

Scholten M, Donahue J, Shaw NL, Serpe MD (2009) Environmental regulation of dormancy loss in seeds of PubMed PMC

Shu K, Liu XD, Xie Q, He ZH (2016) Two faces of one seed: hormonal regulation of dormancy and germination. Mol Plant 9:34–45. 10.1016/j.molp.2015.08.010 PubMed

Sperber K, Steinbrecher T, Graeber K, Scherer G, Clausing S, Wiegand N, Hourston JE, Kurre R, Leubner-Metzger G, Mummenhoff K (2017) Fruit fracture biomechanics and the release of PubMed PMC

Simura J, Antoniadi I, Siroka J, Tarkowská D, Strnad M, Ljung K, Novak O (2018) Plant hormonomics: multiple phytohormone profiling by targeted metabolomics. Plant Physiol 177:476–489. 10.1104/pp.18.00293 PubMed PMC

Sajna N, Sipek M, Sustar-Vozlic J, Kaligaric M (2019) Germination behavior of the extremely rare

Soltani E, Mortazavian SMM, Faghihi S, Akbari GA (2019) Non-deep simple morphophysiological dormancy in seeds of

Soldatenko AV, Buharov AF, Baloov DN, Ivanova MI, Nazarov PA, Razin OA, Razin AF (2020) Impact of high temperature on growth of vembryo and germination of heteromorphic seeds os

Steinbrecher T, Bhattacharya S, Binder J, Kleemeier K, Przesdzink F, Groene F, Jacoblinnert K, Mummenhoff K, Leubner-Metzger G (2025) Comparative pericarp biomechanics and germination physiology of PubMed PMC

Thomas TH, Dearman AS, Biddington NL (1986) Evidence for the accumulation of a germination inhibitor during progressive thermoinhibition of seeds of celery (

Tan SS, Jia M, Zhang X-Y, Duan A-Q, Li T, Liu Y-H, Xiong A-S (2023) Comparative transcriptome analysis provides novel insights into phytohormone dynamic changes during seed germination in carrot (

Unver MC, Tilki F (2012) Salinity, germination promoting chemicals, temperature and light effects on seed germination of

Urbanova T, Tarkowská D, Novák O, Hedden P, Strnad M (2013) Analysis of gibberellins as free acids by ultra performance liquid chromatography-tandem mass spectrometry. Talanta 112:85–94. 10.1016/j.talanta.2013.03.068 PubMed

Van der Toorn P, Karssen CM (1992) Analysis of embryo growth in mature fruits of celery (

Vandelook F, Carta A (2025) Major shifts in embryo size occurred early in the evolutionary history of angiosperms. New Phytol 246:785–796. 10.1111/nph.20445 PubMed

Vandelook F, Bolle N, Van Assche JA (2007a) Multiple environmental signals required for embryo growth and germination of seeds of

Vandelook F, Bolle N, Van Assche JA (2007b) Seed dormancy and germination of the European PubMed PMC

Vandelook F, Bolle N, Van Assche JA (2009) Morphological and physiological dormancy in seeds of

Vandelook F, Janssens SB, Probert RJ (2012) Relative embryo length as an adaptation to habitat and life cycle in Apiaceae. New Phytol 195:479–487. 10.1111/j.1469-8137.2012.04172.x PubMed

Vandelook F, van de Vyver A, Soltani E (2024) Intra-specific variation in relative embryo length and germination of wild

Visscher AM, Vandelook F, Fernandez-Pascual E, Perez-Martinez LV, Ulian T, Diazgranados M, Mattana E (2022) Low availability of functional seed trait data from the tropics could negatively affect global macroecological studies, predictive models and plant conservation. Ann Bot 130:773–784. 10.1093/aob/mcac130 PubMed PMC

Walck JL, Baskin CC, Hidayati SN, Baskin JM (2008) Comparison of the seed germination of native and non-native winter annual Apiaceae in North America, with particular focus on

Walck JL, Hidayati SN (2004) Germination ecophysiology of the western North American species

Walck JL, Hidayati SN, Okagami N (2002) Seed germination ecophysiology of the Asian species PubMed

Walker M, Nakabayashi K, Gawthrop F, Leubner-Metzger G (2025) The initiation of embryo growth in imbibed celery mericarps marks a key mechanism by which temperature signals are integrated to regulate germination timing. J Exp Bot. 10.1093/jxb/eraf326 PubMed

Walker M, Pérez M, Steinbrecher T, Gawthrop F, Pavlovic I, Novák O, Tarkowská D, Strnad M, Marone F, Nakabayashi K, Leubner-Metzger G (2021) Molecular mechanisms and hormonal regulation underpinning morphological dormancy: a case study using PubMed

Willis CG, Baskin CC, Baskin JM, Auld JR, Venable DL, Cavender-Bares J, Donohue K, Rubio de Casas R (2014) The evolution of seed dormancy: environmental cues, evolutionary hubs, and diversification of the seed plants. New Phytol 203:300–309. 10.1111/nph.12782 PubMed

Wojewodzka A, Baczynski J, Banasiak L, Downie SR, Czarnocka-Cieciura A, Gierek M, Frankiewicz K, Spalik K (2019) Evolutionary shifts in fruit dispersal syndromes in Apiaceae tribe Scandiceae. Plant Syst Evol 305:401–414. 10.1007/s00606-019-01579-1

Yan D, Duermeyer L, Leoveanu C, Nambara E (2014) The functions of the endosperm during seed germination. Plant Cell Physiol 55:1521–1533. 10.1093/pcp/pcu089 PubMed

Yeom MS, Nguyen TKL, Cho JS, Oh MM (2021) Improving germination rate of coastal

Zhou YM, Lu JJ, Tan DY, Baskin CC, Baskin JM (2015) Seed germination ecology of the cold desert annual PubMed PMC

Zardari S, Ghaderi-Far F, Sadeghipour HR, Zeinali E, Soltani E, Baskin CC (2019) Deep and intermediate complex morphophysiological dormancy in seeds of

Zhang KL, Yao LJ, Zhang Y, Baskin JM, Baskin CC, Xiong ZM, Tao J (2019a) A review of the seed biology of PubMed

Zhang KL, Zhang Y, Walck JL, Tao J (2019b) Non-deep simple morphophysiological dormancy in seeds of

Zarei-Gavkosh M, Afshari RT, Jahansooz M (2022) Morphophysiological dormancy in

Zhang L, Xu CH, Liu HN, Tao J, Zhang KL (2023) Seed dormancy and germination requirements of