Evidence of genetic segregation in the apogamous fern species Cyrtomium fortunei (Dryopteridaceae)


In apogamous ferns, all offspring from a parent are expected to be clonal. However, apogamous ‘species’ frequently demonstrate a large amount of morphological and genetic variations. Cyrtomium fortunei composed of four varieties (C. fortunei var. fortunei, var. clivicola, var. intermedium, and var. atropunctatum), is all reported to be apogamous triploids, but demonstrates large and continuous morphological variation. In previous studies, we showed that considerable genetic diversity was observed in many local populations of the apogamous fern ‘species’. We hypothesized that genetic segregation has occurred, because neither sexual type nor intraspecific polyploidy have been observed in C. fortunei in Japan. Of 732 progeny examined (250 gametophytes and 482 sporophytes), obtained from a parental sporophyte whose pgiC genotype was estimated as aab, 11 (4.4%) gametophytes and 8 (1.7%) sporophytes showed a different genotype (aaa) from that of the parent sporophyte. We showed that genetic segregation occurs in apogamous C. fortunei in relatively high frequency. Moreover, we could first show that the segregation frequency in gametophytes is significantly higher than that in sporophytes of the next generation (χ 2 = 4.90, P = 0.027). It may suggest the existence of deleterious genes, which are expressed during the morphogenesis and growth of sporophytes.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. Doyle JJ, Doyle JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemistry 19:11–15

    Google Scholar 

  2. Isagi Y, Suyama Y (2011) Single-pollen genotyping. Springer, Tokyo

    Google Scholar 

  3. Ishikawa H, Ito M, Watano Y, Kurita S (2003) Electrophoretic evidence for homoeologous chromosome pairing in the apogamous fern species Dryopteris nipponensis (Dryopteridaceae). J Plant Res 116:165–167

    PubMed  Google Scholar 

  4. Klekowski EJ (1973) Sexual and subsexual systems in homosporous pteridophytes: a new hypothesis. Am J Bot 60:535–544

    Article  Google Scholar 

  5. Lin S-J, Kato M, Iwatsuki K (1992) Diploid and triploid offspring of triploid agamosporous fern Dryopteris pacifica. Bot Mag Tokyo 105:443–452

    Article  Google Scholar 

  6. Lin S-J, Kato M, Iwatsuki K (1995) Electrophoretic variation of the apogamous Dryopteris varia group (Dryopteridaceae). J Plant Res 108:451–456

    Article  Google Scholar 

  7. Lovis JD (1977) Evolutionary patterns and processes in ferns. Adv Bot Res 4:229–415

    Article  Google Scholar 

  8. Manton I (1950) Problems of cytology and evolution in the Pteridophyta. Cambridge University Press, Cambridge

    Google Scholar 

  9. Masuyama S (1996) Progenesis as an adaptive strategy in the annual fern Ceratoperis thalictroides in Japan. Plant Species Biol 11:225–232

    Article  Google Scholar 

  10. Masuyama S, Watano Y (1990) Trends for inbreeding in polyploid pteridophytes. Plant Species Biol 5:13–17

    Article  Google Scholar 

  11. Nakato N, Kato M, Liu BD (1995) A cytotaxonomic study of some ferns from Jiangsu and Zhejiang Provinces, China. J Jpn Bot 70:194–204

    Google Scholar 

  12. Ootsuki R, Shinohara W, Suzuki T, Murakami N (2011) Genetic variation in the apogamous fern Cyrtomium fortunei (Dryopteridaceae). Acta Phytotaxon Geobot 62:1–14

    Google Scholar 

  13. Schneller JJ, Holderegger R (1994) Lack of isozyme variation in agamosporous fern Dryopteris remota (A. Braun) Druce. Am Fern J 84:94–98

    Article  Google Scholar 

  14. Soltis PS, Soltis DE (1990) Genetic-variation within and among populations of ferns. Am Fern J 80:161–172

    Google Scholar 

  15. Suzuki T, Iwatsuki K (1990) Genetic variation in agamosporous fern Pteris cretica L. in Japan. Heredity 65:221–227

    Article  Google Scholar 

  16. Takamiya M (ed) (1996) Index to chromosomes of Japanese Pteridophyta (1910–1996). Japan Pteridol Soc, Tokyo

    Google Scholar 

  17. Takamiya M, Ohta N, Yatabe Y, Murakami N (2001) Cytological, morphological, genetic and molecular phylogenetic studies on intraspecific differentiations within Diplazium doederleinii (Woodsiaceae: Pteridophyta). Int J Plant Sci 162:625–636

    Article  CAS  Google Scholar 

  18. Walker TG (1962) Cytology and evolution in the fern genus Pteris L. Evolution 16:27–43

    Article  Google Scholar 

  19. Watano Y, Iwatsuki K (1988) Genetic variation in the “Japanese apogamous form” of the fern Asplenium unilaterale Lam. Bot Mag Tokyo 101:213–222

    Article  Google Scholar 

Download references


We are grateful to Dr. T. Sugawara and Dr. H. Kato of Makino Herbarium, Tokyo Metropolitan University, Dr. Y. Yatabe-Kakugawa, Botanical Gardens, University of Tokyo, Dr. S. Matsumoto of the National Science Museum, Tsukuba, and Dr. S. Masuyama for their valuable suggestions and advice during the course of this study. We are also grateful to Dr. H. Ishikawa, Kitasato University, for showing us his unpublished data. This study is partly supported by a Grant-in-Aid for Scientific Research (#21370037) from the Japan Society for the Promotion of Science to N.M.

Author information



Corresponding author

Correspondence to Ryo Ootsuki.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ootsuki, R., Sato, H., Nakato, N. et al. Evidence of genetic segregation in the apogamous fern species Cyrtomium fortunei (Dryopteridaceae). J Plant Res 125, 605–612 (2012). https://doi.org/10.1007/s10265-012-0483-9

Download citation


  • Apogamy
  • Cyrtomium fortunei
  • Deleterious genes
  • Genetic segregation
  • Ploidy