INTRODUCTION: Plants undergo various natural changes that dramatically modify their genomes. One is polyploidization and the second is hybridization. Both are regarded as key factors in plant evolution and result in phenotypic differences in different plant organs. In Silene, we can find both examples in nature, and this genus has a seed shape diversity that has long been recognized as a valuable source of information for infrageneric classification. METHODS: Morphometric analysis is a statistical study of shape and size and their covariations with other variables. Traditionally, seed shape description was limited to an approximate comparison with geometric figures (rounded, globular, reniform, or heart-shaped). Seed shape quantification has been based on direct measurements, such as area, perimeter, length, and width, narrowing statistical analysis. We used seed images and processed them to obtain silhouettes. We performed geometric morphometric analyses, such as similarity to geometric models and elliptic Fourier analysis, to study the hybrid offspring of S. latifolia and S. dioica. RESULTS: We generated synthetic tetraploids of Silene latifolia and performed controlled crosses between diploid S. latifolia and Silene dioica to analyze seed morphology. After imaging capture and post-processing, statistical analysis revealed differences in seed size, but not in shape, between S. latifolia diploids and tetraploids, as well as some differences in shape among the parentals and hybrids. A detailed inspection using fluorescence microscopy allowed for the identification of shape differences in the cells of the seed coat. In the case of hybrids, differences were found in circularity and solidity. Overal seed shape is maternally regulated for both species, whereas cell shape cannot be associated with any of the sexes. DISCUSSION: Our results provide additional tools useful for the combination of morphology with genetics, ecology or taxonomy. Seed shape is a robust indicator that can be used as a complementary tool for the genetic and phylogenetic analyses of Silene hybrid populations.

Department of Plant Developmental Genetics Institute of Biophysics of the Czech Academy of Sciences Brno Czechia

Instituto de Recursos Naturales y Agrobiología de Salamanca CSIC Salamanca Spain

National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czechia

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Akagi T., Fujita N., Masuda K., Shirasawa K., Nagaki K., Horiuchi A., et al. (2023). Rapid and dynamic evolution of a giant Y chromosome in PubMed

Arganda-Carreras I., Kaynig V., Rueden C., Eliceiri K. W., Schindelin J., Cardona A., et al. (2017). Trainable Weka Segmentation: a machine learning tool for microscopy pixel classification. Bioinformatics 33, 2424–2426. doi:  10.1093/bioinformatics/btx180 PubMed DOI

Baena-Diaz F., Zemp N., Widmer A. (2019). Insights into the genetic architecture of sexual dimorphism from an interspecific cross between two diverging PubMed DOI

Baker H. (1950). The inheritance of certain characters in crosses between PubMed DOI

Balounova V., Gogela R., Cegan R., Cangren P., Zluvova J., Safar J., et al. (2019). Evolution of sex determination and heterogamety changes in section Otites of the genus Silene. Sci. Rep. 9, 1–13. doi:  10.1038/s41598-018-37412-x PubMed DOI PMC

Baskin C. C., Baskin J. M. (1998). Seeds: ecology, biogeography, and, evolution of dormancy and germination (San Diego California: Elsevier; ).

Beaulieu J. M., Moles A. T., Leitch I. J., Bennett M. D., Dickie J. B., Knight C. A. (2007). Correlated evolution of genome size and seed mass. New Phytol. 173, 422–437. doi:  10.1111/j.1469-8137.2006.01919.x PubMed DOI

Benítez H., Lemic D., Villalobos-Leiva A., Bažok R., Órdenes-Claveria R., Pajač Živković I., et al. (2020). Breaking symmetry: Fluctuating Asymmetry and Geometric Morphometrics as tools for evaluating developmental instability under diverse agroecosystems. Symmetry 12, 1789. doi:  10.3390/sym12111789 DOI

Bernasconi G., Antonovics J., Biere A., Charlesworth D., Delph L. F., Filatov D., et al. (2009). PubMed DOI

Blackburn K. B. (1933). On the relation between geographic races and polyploidy in DOI

Blair A. C., Wolfe L. M. (2004). The evolution of an invasive plant: an experimental study with DOI

Bonhomme V., Picq S., Gaucherel C., Claude J. (2014). Momocs: outline analysis using R. J. Stat. Softw. 56, 1–24. doi:  10.18637/jss.v056.i13 DOI

Breno M., Bots J., Van Dongen S. (2013). Heritabilities of directional asymmetry in the fore-and hindlimbs of rabbit fetuses. PloS One 8, e76358. doi:  10.1371/journal.pone.0076358 PubMed DOI PMC

Casimiro-Soriguer I., Buide M. L., Narbona E. (2015). Diversity of sexual systems within different lineages of the genus PubMed DOI PMC

Cervantes E., Rodríguez-Lorenzo J. L., Gutiérrez Del Pozo D., Martín-Gómez J. J., Janousek B., Tocino Á., et al. (2022). Seed silhouettes as geometric objects: New applications of Elliptic Fourier Transform to seed morphology. Horticulturae 8, 974. doi:  10.3390/horticulturae8100974 DOI

Charlesworth D. (2013). Plant sex chromosome evolution. J. Exp. Bot. 64, 405–420. doi:  10.1093/jxb/ers322 PubMed DOI

Coyne J. A. (1992). Genetics and speciation. Nature 355, 511–515. doi:  10.1038/355511a0 PubMed DOI

Dadandi M. Y., Yildiz K. (2015). Seed morphology of some DOI

Dowd C. (2022). twosamples: Fast permutation based two sample tests, R.P.V. 2.0.0. Available at: https://CRAN.R-project.org/package=twosamples.

Ehlers K., Bhide A. S., Tekleyohans D. G., Wittkop B., Snowdon R. J., Becker A. (2016). The MADS Box genes ABS, SHP1, and SHP2 are essential for the coordination of cell divisions in ovule and seed coat development and for endosperm formation in PubMed DOI PMC

Eliášová A., Münzbergová Z. (2014). Higher seed size and germination rate may favour autotetraploids of

Goulson D. (2009). Evaluating the role of ecological isolation in maintaining the species boundary between DOI

Graham J. H., Raz S., Hel-Or H., Nevo E. (2010). Fluctuating asymmetry: methods, theory, and applications. Symmetry 2, 466–540. doi:  10.3390/sym2020466 DOI

Gutiérrez Del Pozo D., Martín-Gómez J. J., Tocino Á., Cervantes E. (2020). Seed geometry in the DOI

He L., Horandl E. (2022). Does polyploidy inhibit sex chromosome evolution in angiosperms? Front. Plant Sci. 13, 976765. PubMed PMC

Hobza R., Hrusakova P., Safar J., Bartos J., Janousek B., Zluvova J., et al. (2006). MK17, a specific marker closely linked to the gynoecium suppression region on the Y chromosome in Silene latifolia. Theor. Appl. Genet. 130, 280–287. PubMed

Hobza R., Kejnovsky E., Vyskot B., Widmer A. (2007). The role of chromosomal rearrangements in the evolution of PubMed DOI

Hobza R., Widmer A. (2008). Efficient molecular sexing in dioecious PubMed

Hoseini E., Ghahremaninejad F., Assadi M., Edalatiyan M. N. (2017). Seed micromorphology and its implication in subgeneric classification of DOI

Iwata H., Niikura S., Matsuura S., Takano Y., Ukai Y. (1998). Evaluation of variation of root shape of Japanese radish ( DOI

Jafari F., Zarre S., Gholipour A., Eggens F., Rabeler R. K., Oxelman B. (2020). A new taxonomic backbone for the infrageneric classification of the species-rich genus DOI

Janoušek B., Hobza R., Vyskot B. (2013). “Chromosomes and sex differentiation,” in Plant Genome Diversity Volume 2 (Vienna: Springer; ), 167–186.

Johri B. M., Ambegaokar K. B., Srivastava P. S. (2013). Comparative embryology of angiosperms vol. 1/2 (Berlin Heidelberg GmbH: Springer-Verlag; ).

Juan A., Martín-Gómez J. J., Rodríguez-Lorenzo J. L., Janoušek B., Cervantes E. (2021). New techniques for seed shape description in

Karrenberg S., Favre A. (2008). Genetic and ecological differentiation in the hybridizing campions PubMed DOI

Karrenberg S., Liu X., Hallander E., Favre A., Herforth-Rahme J., Widmer A. (2019). Ecological divergence plays an important role in strong but complex reproductive isolation in campions ( PubMed DOI

Kassambara A., Mundt F. (2017). Package ‘factoextra’. Extract visual. results multivariate Data anal. 76. Available at: https://CRAN.R-project.org/package=factoextra.

Klingenberg C. P. (2008). Morphological integration and developmental modularity. Annu. Rev. Ecol. Evol. System. 39, 115–132. doi:  10.1146/annurev.ecolsys.37.091305.110054 DOI

Kuhl F. P., Giardina C. R. (1982). Elliptic Fourier features of a closed contour. Comput. Graphics image Process. 18, 236–258. doi:  10.1016/0146-664X(82)90034-X DOI

Ladero M., Rivas-Martinez S., Amor A., Santos M. T., Alonso M. T. (1999). New hybrid of genus DOI

Li N., Xu R., Li Y. (2019). Molecular networks of seed size control in plants. Annu. Rev. Plant Biol. 70, 435–463. doi:  10.1146/annurev-arplant-050718-095851 PubMed DOI

Liu X., Karrenberg S. (2018). Genetic architecture of traits associated with reproductive barriers in PubMed DOI

Marais G. A., Nicolas M., Bergero R., Chambrier P., Kejnovsky E., Moneger F., et al. (2008). Evidence for degeneration of the Y chromosome in the dioecious plant PubMed DOI

Martin A. C. (1946). The comparative internal morphology of seeds. Am. Midland Nat. 36, 513–660. doi:  10.2307/2421457 DOI

Martín-Gómez J. J., Porceddu M., Bacchetta G., Cervantes E. (2022. a). Seed morphology in species from the PubMed DOI PMC

Martín-Gómez J. J., Rewicz A., Rodríguez-Lorenzo J. L., Janoušek B., Cervantes E. (2020). Seed morphology in PubMed DOI PMC

Martín-Gómez J. J., Rodríguez-Lorenzo J. L., Janoušek B., Juan A., Cervantes E. (2023). Comparison of seed images with geometric models, an approach to the morphology of DOI

Martín-Gómez J. J., Rodríguez-Lorenzo J. L., Juan A., Tocino Á., Janousek B., Cervantes E. (2022. b). Seed morphological properties related to taxonomy in DOI

Matzig D. N. (2021). outlineR: An R package to derive outline shapes from (multiple) artefacts on JPEG images (0.1.0). (Zenodo). doi:  10.5281/zenodo.4527470 DOI

McLellan T., Endler J. A. (1998). The relative success of some methods for measuring and describing the shape of complex objects. System. Biol. 47, 264–281. doi:  10.1080/106351598260914 DOI

Minder A. M., Rothenbuehler C., Widmer A. (2007). Genetic structure of hybrid zones between PubMed DOI

Mohana Rao P., Guignard J.-L., Duret S. (1988). An ultrastructural study of perisperm and endosperm in

Møller A. P., Pomiankowski (1993). Fluctuating asymmetry and sexual selection. Genetica 89, 267–279. doi:  10.1007/BF02424520 DOI

Moraga C., Branco C., Rougemont Q., Veltsos P., Jedlicka P., Muyle A., et al. (2023). The PubMed PMC

Nowak J., Eng R. C., Matz T., Waack M., Persson S., Sampathkumar A., et al. (2021). A network-based framework for shape analysis enables accurate characterization of leaf epidermal cells. Nat. Commun. 12, 458. doi:  10.1038/s41467-020-20730-y PubMed DOI PMC

Ohnishi Y., Kawashima T. (2020). Plasmogamic paternal contributions to early zygotic development in flowering plants. Front. Plant Sci. 11, 871. doi:  10.3389/fpls.2020.00871 PubMed DOI PMC

Page P., Favre A., Schiestl F. P., Karrenberg S. (2014). Do flower color and floral scent of PubMed DOI PMC

Popp M., Oxelman B. (2007). Origin and evolution of north american polyploid PubMed DOI

POWO . (2022). Plants of the World Online. Facilitated by the Royal Botanic Gardens (Royal Botanic Gardens, Kew, UK: ).

R Development Core Team . (2023). R: A language and environment for statistical computing (Vienna, Austria: R Foundation for Statistical Computing; ).

Rodríguez-Lorenzo J. L., Martín-Gómez J. J., Tocino Á., Juan A., Janoušek B., Cervantes E. (2022). New geometric models for shape quantification of the dorsal view in seeds of PubMed DOI PMC

Sayers E. W., Bolton E. E., Brister J. R., Canese K., Chan J., Comeau D. C., et al. (2022). Database resources of the national center for biotechnology information. Nucleic Acids Res. 50, D20–d26. doi:  10.1093/nar/gkab1112 PubMed DOI PMC

Schindelin J., Arganda-Carreras I., Frise E., Kaynig V., Longair M., Pietzsch T., et al. (2012). Fiji: an open-source platform for biological-image analysis. Nat. Methods 9, 676–682. doi:  10.1038/nmeth.2019 PubMed DOI PMC

Sheidai M., Eftekharian R., Gholipoor A., Noormohammadi Z. (2011). Population diversity and polyploidy incidence in 3

Siroký J., Hodurkova J., Negrutiu I., Vyskot B. (1999). Functional and structural chromosome analyses in autotetraploid DOI

Široký J., Lysák M. A., Doležel J., Kejnovský E., Vyskot B. (2001). Heterogeneity of rDNA distribution and genome size in PubMed

Slancarova V., Zdanska J., Janousek B., Talianova M., Zschach C., Zluvova J., et al. (2013). Evolution of sex determination systems with heterogametic males and females in PubMed DOI

Spillane C., Vielle-Calzada J., Grossniklaus U. (2002). “Parent-of-origin effects and seed development: Genetics and epigenetics,” Transgenic Plants Crops. in Khachatourians G. C., Hui Y. H., Scorza R., Nip W.-K. (Boca Raton; ). 109–135. doi:  10.1201/9780203910979 DOI

Statistics I. (2021). IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 22.0 (Armonk, NY: IBM Corp; ).

Steven J. C., Anderson I. A., Brodie Iii E. D., Delph L. F. (2020). Rapid reversal of a potentially constraining genetic covariance between leaf and flower traits in PubMed DOI PMC

Stevens A., Nicotra A., Godfree R., Guja L. K. (2020). Polyploidy affects the seed, dormancy and seedling characteristics of a perennial grass, conferring an advantage in stressful climates. Plant Biol. 22, 500–513. doi:  10.1111/plb.13094 PubMed DOI

Storchova H. (2011). “Genome structure and gene expression variation in plant mitochondria, particularly in the Genus

Taylor D. R. (1994). Sex ratio in hybrids between PubMed DOI

Thompson P. (1981). Variations in seed size within populations of

Thompson K. A., Urquhart-Cronish M., Whitney K. D., Rieseberg L. H., Schluter D. (2021). Patterns, predictors, and consequences of dominance in hybrids. Am. Nat. 197, E72–E88. doi:  10.1086/712603 PubMed DOI

Van Nigtevecht G. (1966). Genetic studies in dioecious DOI

Vercken E., Fontaine M. C., Gladieux P., Hood M. E., Jonot O., Giraud T. (2010). Glacial refugia in pathogens: European genetic structure of anther smut pathogens on PubMed DOI PMC

Warmke H. E., Blakeslee A. F. (1939). Sex mechanism in polyploids of PubMed DOI

Westergaard M. (1946). Structural changes of the Y chromosome in the offspring of polyploid PubMed DOI

Ye D., Installé P., Ciupercescu D., Veuskens J., Wu Y., Salesses G., et al. (1990). Sex determination in the dioecious DOI

Yildiz K., Cirpici A. (1998). Seed morphological studies of

Yue J., Krasovec M., Kazama Y., Zhang X., Xie W., Zhang S., et al. (2023). The origin and evolution of sex chromosomes, revealed by sequencing of the PubMed DOI PMC

Zluvova J., Zak J., Janousek B., Vyskot B. (2010). Dioecious PubMed DOI PMC