Plant Systematics and Evolution

, Volume 303, Issue 4, pp 497–507 | Cite as

Spore abortion index (SAI) as a promising tool of evaluation of spore fitness in ferns: an insight into sexual and apomictic species

  • Ondřej Hornych
  • Libor Ekrt
Original Article


Ferns reproduce through small and usually haploid spores. The general paradigm states that whereas species produce good shaped spores, hybrids are sterile and form aborted spores. Apomictic fern species represent an unusual case, and it is believed that they produce an unbalanced spore spectrum. Until now, no comprehensive comparison of sexual and apomictic taxa using extensive spore fitness data has been published. Based on a representative data set of 109 plants from 23 fern taxa, we accomplished the first robust analysis of spore fitness using spore abortion index (SAI), the ratio of aborted to all examined spores. One thousand spores were analyzed for each plant. Focusing mainly on two major European fern taxa (Asplenium, Dryopteris), we compared this trait for different fern reproductive types (sexual/apomicts/hybrids) and ploidy levels (diploid versus polyploid). Our results confirmed the general assumption that shows higher SAI for apomictic taxa (18%) when compared to sexual taxa (3%). Furthermore, hybrids are characterized by having almost all spores aborted (99.8%) with the notable exception of pentaploid Dryopteris × critica (93.1%), the hybrid between sexual and apomictic taxa. We found no significant difference in SAI between sexual taxa of various ploidy levels or between sexual taxa of genera Dryopteris and Asplenium. Additionally, we carried out an optimization of the SAI method, outlying important guidelines for the use of this method in the future.


Apomixis Asplenium Dryopteris Ferns Spore abortion percentage 



We would like to thank the two anonymous reviewers for their helpful advice. We would also like to thank Petr Koutecký for helping us with the statistical analyses. This project was supported by Grant Agency of University of South Bohemia in České Budějovice (Project Number: 148/2016/P) and by Czech Science Foundation (Project No. 14-36079G, Centre of Excellence PLADIAS).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

606_2016_1386_MOESM1_ESM.pdf (438 kb)
Supplementary material 1 (PDF 437 kb)
606_2016_1386_MOESM2_ESM.pdf (398 kb)
Supplementary material 2 (PDF 398 kb)


  1. Aragon CF, Pangua E (2004) Spore viability under different storage conditions in four rupicolous Asplenium L. Taxa. Amer Fern J 94:28–38. doi: 10.1640/0002-8444(2004)094[0028:SVUDSC]2.0.CO;2 CrossRefGoogle Scholar
  2. Arosa ML, Quintanilla LG, Ramos JA, Ceia R, Sampaio H (2009) Spore maturation and release of two evergreen Macaronesian ferns, Culcita macrocarpa and Woodwardia radicans, along an altitudinal gradient. Amer Fern J 99:260–272. doi: 10.1640/0002-8444-99.4.260 CrossRefGoogle Scholar
  3. Bär A, Eschelmüller A (2010) Farnstudien: Einige pentaploide Bastarde von Dryopteris filix-mas mit triploiden Vertretern der Dryopteris-Gruppe. Ber Bayer Bot Ges 80:119–140Google Scholar
  4. Blockeel TL (2006) The liverworts, mosses and ferns of Europe. Harley Books, ColchesterGoogle Scholar
  5. Braithwaite AF (1964) A new type of apogamy in ferns. New Phytol 63:293–305CrossRefGoogle Scholar
  6. Dafni A, Firmage D (2000) Pollen viability and longevity: practical, ecological and evolutionary implications. Pl Syst Evol 222:113–132. doi: 10.1007/BF00984098 CrossRefGoogle Scholar
  7. Danihelka J, Chrtek J Jr, Kaplan Z (2012) Checklist of vascular plants of the Czech Republic. Preslia 84:647–811Google Scholar
  8. Dell Inc. (2015) Dell Statistica (data analysis software system), version 13. Available at:
  9. Dyer RJ, Savolainen V, Schneider H (2012) Apomixis and reticulate evolution in the Asplenium monanthes fern complex. Ann Bot (Oxford) 110:1515–1529. doi: 10.1093/aob/mcs202 CrossRefGoogle Scholar
  10. Ekrt L, Koutecký P (2016) Between sexual and apomictic: unexpectedly variable sporogenesis and production of viable polyhaploids in the pentaploid fern of the Dryopteris affinis agg. (Dryopteridaceae). Ann Bot (Oxford) 117:97–106. doi: 10.1093/aob/mcv152 CrossRefGoogle Scholar
  11. Ekrt L, Štech M (2008) A morphometric study and revision of the Asplenium trichomanes group in the Czech Republic. Preslia 80:325–347Google Scholar
  12. Ekrt L, Trávníček P, Jarolímová V, Vít P, Urfus T (2009) Genome size and morphology of the Dryopteris affinis group in Central Europe. Preslia 81:261–280Google Scholar
  13. Ekrt L, Holubová R, Trávníček P, Suda J (2010) Species boundaries and frequency of hybridization in the Dryopteris carthusiana (Dryopteridaceae) complex: a taxonomic puzzle resolved using genome size data. Amer J Bot 97:1208–1219. doi: 10.3732/ajb.0900206 CrossRefGoogle Scholar
  14. Eschelmüller A (1993) Dryopteris remota vom “Wachterl” keimt am besten. Mitteilungen des Naturwissenschaftlichen Arbeitskreises Kempten 30:5–22Google Scholar
  15. Eschelmüller A (1998) Keimversuche mit Sporen der triploiden Sippen von Dryopteris affinis und ihren Bastarden mit Dryopteris filix-mas. Mitt  Naturwiss Arbeitskreises Kempten 36:47–78Google Scholar
  16. Fraser-Jenkins CR (2007) The species and subspecies in the Dryopteris affinis group. Fern Gaz 18:1–26Google Scholar
  17. Gastony GJ, Windham MD (1989) Species concepts in pteridophytes: the treatment and definition of agamosporous species. Amer Fern J 79:65–77CrossRefGoogle Scholar
  18. Gomes SG, Randi AM, Puchalskil A, Santos DDS, dos Reis MS (2006) Variability in the germination of spores among and within natural populations of the endangered tree fern Dicksonia sellowiana Hook. (Xaxim). Brazil Arch Biol Technol 49:1–10. doi: 10.1590/S1516-89132006000100001 CrossRefGoogle Scholar
  19. Greer GK, McCarthy BC (2000) Patterns of growth and reproduction in a natural population of the fern Polystichum acrostichoides. Amer Fern J 90:60–76. doi: 10.2307/1547415 CrossRefGoogle Scholar
  20. Guo ZY, Liu HM (2013) Gametophyte morphology and development of three species of Cyrtogonellum Ching (Dryopteridaceae). Amer Fern J 103:153–165. doi: 10.1640/0002-8444-103.3.153 CrossRefGoogle Scholar
  21. Hanušová K, Ekrt L, Vít P, Kolář F, Urfus T (2014) Continuous morphological variation correlated with genome size indicates frequent introgressive hybridization among Diphasiastrum species (Lycopodiaceae) in Central Europe. PLoS ONE 9:e99552. doi: 10.1371/journal.pone.0099552 CrossRefPubMedPubMedCentralGoogle Scholar
  22. Haufler CH, Pryer KM, Schuettlepz E, Sessa EB, Farrar DR, Moran R, Schneller JJ, Watkins JE, Windham M (2016) Sex and the single gametophyte: revising the homosporous vascular plant life cycle in light of contemporary research. BioScience (in press). doi: 10.1093/biosci/biw108 Google Scholar
  23. Hernández MA, Andrada AR, Páez VDLA, Martínez OG (2015) Ploidy level and obligate apogamy in two populations of Argyrochosma nivea var. tenera (Pteridaceae). Hoehnea 42:233–237. doi: 10.1590/2236-8906-36/2014 CrossRefGoogle Scholar
  24. Johnson MTJ, Smith SD, Rauscher MD (2010) Effects of plant sex on range distributions and allocation to reproduction. New Phytol 186:769–779. doi: 10.1111/j.1469-8137.2010.03201.x CrossRefPubMedGoogle Scholar
  25. Kawakami SM, Kawakami S, Kato J, Kondo K, Smirnov SV, Damdinsuren O (2010) Cytological study of a fern Cystopteris fragilis in Mongolian Altai. Chromosome Bot 5:1–3CrossRefGoogle Scholar
  26. Khare PB, Kaur S (1983) Gametophyte differentiation of pentaploid Pteris vittata L. Proc Natl Acad Sci India 49:740–742Google Scholar
  27. Kott LS, Britton DM (1982) A comparative study of spore germination of some Isoëtes species of northeastern North America. Canad J Bot 60:1679–1687CrossRefGoogle Scholar
  28. Kott LS, Peterson RL (1973) A comparative study of gametophyte development of the diploid and tetraploid races of Polypodium virginianum. Canad J Bot 52:91–96CrossRefGoogle Scholar
  29. Lovis JD (1977) Evolutionary patterns and processes in ferns. Advances Bot Res 4:229–415CrossRefGoogle Scholar
  30. Manton I (1950) Problems of cytology and evolution in the Pteridophyta. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  31. Mesipuu M, Shefferson RP, Kull T (2009) Weather and herbivores influence fertility in the endangered fern Botrychium multifidum (S.G. Gmel.). Rupr. Pl Ecol 203:23–31. doi: 10.1007/s11258-008-9501-3 CrossRefGoogle Scholar
  32. Nakato N, Ootsuki R, Murakami N, Masuyama S (2012) Two types of partial fertility in a diploid population of the fern Thelypteris decursive-pinnata (Thelypteridaceae). J Pl Res 125:465–474. doi: 10.1007/s10265-011-0461-7 CrossRefGoogle Scholar
  33. Odland A (1998) Size and reproduction of Thelypteris limbosperma and Athyrium distentifolium along environmental gradients in Western Norway. Nordic J Bot 18:311–321. doi: 10.1111/j.1756-1051.1998.tb01882.x CrossRefGoogle Scholar
  34. Pangua E, Quintanilla LG, Sancho A, Pajarón S (2003) A comparative study of the gametophytic generation in the Polystichum aculeatum group (Pteridophyta). Int J Pl Sci 164:295–303. doi: 10.1086/346165 CrossRefGoogle Scholar
  35. Park C, Kato M (2003) Apomixis in the interspecific triploid hybrid fern Cornopteris christenseniana (Woodsiaceae). J Pl Res 116:93–103. doi: 10.1007/s10265-003-0081-y Google Scholar
  36. Pinter I (1995) Progeny studies of the fern hybrid Polystichum × bicknelli i. Fern Gaz 15:25–40Google Scholar
  37. Quintanilla LG, Escudero A (2006) Spore fitness components do not differ between diploid and allotetraploid species of Dryopteris (Dryopteridaceae). Ann Bot (Oxford) 98:609–618. doi: 10.1093/aob/mcl137 CrossRefGoogle Scholar
  38. R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria.
  39. Schneider H, Russell SJ, Cox CJ, Bakker FT, Henderson S, Rumsey F, Barrett J, Gibby M, Vogel JC (2004) Chloroplast phylogeny of asplenioid ferns based on rbcL and trnL-F spacer sequences (Polypodiidae, Aspleniaceae) and its implications for biogeography. Syst Bot 29:260–274. doi: 10.1600/036364404774195476 CrossRefGoogle Scholar
  40. Sessa EB, Zimmer EA, Givnish TJ (2012) Phylogeny, divergence times, and historical biogeography of New World Dryopteris (Dryopteridaceae). Amer Fern J 99:730–750. doi: 10.3732/ajb.1100294 Google Scholar
  41. Thiers B (2016) Index Herbariorum: a global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. Available at: Accessed Aug 2016
  42. Vogel JC, Rumsey FJ, Schneller JJ, Barrett JA, Gibby M (1999) Where are the glacial refugia in Europe? Evidence from pteridophytes. Biol J Linn Soc 66:23–37. doi: 10.1111/j.1095-8312.1999.tb01915.x CrossRefGoogle Scholar
  43. Wagner WH Jr, Chen LC (1965) Abortion of spores and sporangia as a tool in the detection of Dryopteris hybrids. Amer Fern J 55:9–29CrossRefGoogle Scholar
  44. Walker TG (1962) Cytology and evolution in the fem genus Pteris L. Evolution 16:27–43CrossRefGoogle Scholar
  45. Whittier DP, Braggins JE (1994) Spore germination in the Psilotaceae. Canad J Bot 72:688–692. doi: 10.1139/b94-089 CrossRefGoogle Scholar
  46. Windham MD, Ranker TA (1986) Factors affecting prolonged spore viability in herbarium collections of three species of Pellaea. Amer Fern J 76:141–148. doi: 10.2307/1547722 CrossRefGoogle Scholar
  47. Yatabe Y, Yamamota K, Tsutsumi C, Shinohara W, Murakami N, Kato M (2011) Fertility and precocity of Osmunda × intermedia offspring in culture. J Pl Res 124:265–268. doi: 10.1007/s10265-010-0374-x CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Wien 2017

Authors and Affiliations

  1. 1.Department of Botany, Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzech Republic

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