Abstract
Begonia L. is an ideal model for studying plant diversity due to its high species richness and diversity. In this study, we performed detailed cytological analysis for plants collected from 13 wild populations of Begonia handelii, a highly diverse species classified into three varieties. We first determined the chromosome number of these plants and identified diploid, tetraploid, and hexaploid individuals with 2n=22, 44, and 66 chromosomes, respectively. Surprisingly, three plants were found to have 2n=24 chromosomes. The number and position of both 5S and 45S rDNA in these B. handelii plants were determined using fluorescence in situ hybridization (FISH). The rDNA-FISH analysis revealed that the number of loci for both rDNA types was consistent within each ploidy level, with tetraploid and hexaploid individuals having two and three times the number of loci observed in diploid individuals, respectively. In addition, genomic in situ hybridization (GISH) was used to analyze the genomic relationships among the three varieties and to determine the auto- or allopolyploidy of the polyploid plants. The results suggest that the individuals with 2n=24 chromosomes may be hybrids, the tetraploid individuals may be allopolyploids, while hexaploid individuals may be autohexaploids.
References
- Berjano, R., Roa, F., Talavera, S. & Guerra, M. (2009) Cytotaxonomy of diploid and polyploid Aristolochia (Aristolochiaceae) species based on the distribution of CMA/DAPI bands and 5S and 45S rDNA sites. Plant Systematics and Evolution 280: 219–227. https://doi.org/10.1007/s00606-009-0184-6
- Blume, C.L. (1823) Begonia longifolia. In: Catalogus van eenige der Merkwaardigste Zoo In- als Uitheemse Gewassen te Vinden in ‘s Lands Plantentuin te Buitenzorg. Batavia: Lands Drukkerij, 102 pp.
- Braz, G.T., He, L., Zhao, H., Zhang, T.,Semrau, K., Rouillard, J.,Torres, G.A. & Jiang, J. (2018) Comparative Oligo-FISH mapping: an efficient and powerful methodology to reveal karyotypic and chromosomal evolution. Genetics 208: 513–523. https://doi.org/10.1534/genetics.117.300344
- Breda, E.,Wolny, E. & Hasterok, R. (2012) Intraspecific polymorphism of ribosomal DNA loci number and morphology in Brachypodium pinnatum and Brachypodium sylvaticum. Cellular and Molecular Biology Letters 17: 526–541. https://doi.org/10.2478/s11658-012-0025-4
- Campos-Domínguez, L., Pellicer, J., Matthews, A., Leitch, I.J. & Kidner, C.A. (2022) Evolutionary patterns of genome size and chromosome number variation in Begoniaceae. Edinburgh Journal of Botany 79: 1–28. https://doi.org/10.24823/EJB.2022.1876
- Dewitte, A., Eckhaut, T., van Huylenbroeck, J. & van Bockstaele, E. (2009a) Occurrence of viable unreduced pollen in a Begonia collection. Euphytica 161: 81–94. https://doi.org/10.1007/s10681-009-9891-x
- Dewitte, A., Leus, L., Eeckhaut, T., Vanstechelman, I.,Van Huylenbroeck, J. & Van Bockstaele, E. (2009b) Genome size variation in Begonia. Genome 52: 829–838. https://doi.org/10.1139/G09-056
- Dewitte, A., Eeckhaut, T., Van Huylenbroeck, J. & Van Bockstaele, E. (2010) Induction of unreduced pollen by trifluralin and N2O treatments. Euphytica 171: 283–293. https://doi.org/10.1007/s10681-009-0060-z
- Dewitte, A., Twyford, A.D., Thomas, D.C., Kidner, C.A. & Van Huylenbroeck, J. (2011) The origin of diversity in Begonia: genome dynamism, population processes and phylogenetic patterns. In: Venora, G., Grillo, O. & Lopez-Pujol, J. (Eds.) The Dynamical Processes of Biodiversity – Case Studies of Evolution and Spatial Distribution. InTech, Rijeka, pp. 27–52. https://doi.org/10.5772/23789
- Ding, Y.F., Chen, F., Lu, Y.L., Huang, B.H. & Chen, B.Y. (2021) Analysis of aroma components in the flowers of Begonia handelii and its varieties by HS-SPME/GC-MS. Subtropical Plant Science 50: 347–352. [In Chinese with English Abstract] https://doi.org/10.3969/j.issn.1009-7791.2021.05.003
- Don, D. (1825) Begonia palmata. In: Prodromus Florae Nepalensis. London: J. Gale. pp. 223.
- Doyle, J.J. & Doyle, J.L. (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemical Bulletin 19: 11–15.
- Dryander, J. (1791) Begonia grandis. In: Transactions of the Linnean Society of London 1. pp. 163.
- Forest, L.L., Hughes, M. & Hollingsworth, P.M. (2005) A phylogeny from Begonia using nuclear ribosomal sequence data and morphological characters. Systematic Botany 30: 671–682. https://doi.org/10.1600/0363644054782297
- Fransz, P., Armstrong, S., Alonso-Blanco, C., Fischer, T.C., Torres-Ruiz, R.A. & Jones, G. (1998) Cytogenetics for the model system Arabidopsis thaliana. Plant Journal 13: 867–876. https://doi.org/10.1046/j.1365-313x.1998.00086.x
- Garcia, S., Kovărík, A., Leitch, A.R. & Garnatje, T. (2017) Cytogenetic features of rRNA genes across land plants: analysis of the plant rDNA database. Plant Journal 89: 1020–1030. https://doi.org/10.1111/tpj.13442
- Gu, C.Z., Peng, C.I & Turland, N.J. (2007) Begoniaceae. In: Wu, Z.Y.,raven, P.H.& Hong, D.Y. (Eds.) Flora of China. Science Press, Beijing, pp. 153–207.
- Guerra, M. (2008) Chromosome numbers in plant cytotaxonomy: Concepts and implications. Cytogenetic and Genome Research 120: 339–350. https://doi.org/10.1159/000121083
- Han, Y.L., Tian, D.K., Fu, N.F., Xiao, Y., Li, Z.Y. & Han, Y.H. (2018) Comparative analysis of rDNA distribution in 29 species of Begonia sect. Coelocentrum Irmsch. Phytotaxa 381: 141–152. https://doi.org/10.11646/phytotaxa.381.1.18
- Hance, H.F. (1883) Three new Chinese begonias. The Journal of Botany British and Foreign 21: 202–203.
- Hughes, M. & Hollingsworth, P.M. (2008) Population genetic divergence corresponds with species level biodiversity patterns in the large genus Begonia. Molecular Ecology 17: 2643–2651. https://doi.org/10.1111/j.1365-294X.2008.03788.x
- Hughes, M., Moonlight, P.W., Jara-Muñoz, A., Tebbitt, M.C. & Pullan, M. (2015 onwards) Begonia Resource Centre. Available from: https://padme.rbge.org.uk/begonia/page/home (accessed 20 January 2025)
- Irmscher, E. (1921) Plantae novae Sinensis, diagnostibus brevibus descriptae a Dr Henr. Handel-Mazzetti Anzeiger der Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Klasse 58: 24–27.
- Jiang, J.M., Gill, B.S., Wang, G.L., Ronald, P.C. & Ward, D.C. (1995) Metaphase and interphase fluorescence in situ hybridization mapping of the rice genome with bacterial artificial chromosomes. Proceedings of the National Academy of Sciences USA 92: 4487–4491. https://doi.org/10.1073/pnas.92.10.4487
- Jiang, J.M. & Gill, B.S. (2006) Current status and the future of fluorescence in situ hybridization (FISH) in plant genome research. Genome 49: 1057–1068.
- https://doi.org/10.1139/g06-076
- Kolano, B., Saracka, K., Broda-Cnota, A. & Maluszynska, J. (2013) Localization of ribosomal DNA and CMA3/DAPI heterochromatin in cultivated and wild Amaranthus species. Scientia Horticulturae 164: 249–255. https://doi.org/10.1016/j.scienta.2013.09.016
- Kono, Y., Chung, M.C. & Peng, C.I. (2012) Identification of genome constitutions in Begonia×chungii and its putative parents, B. longifolia and B. palmata, by genomic in situ hybridization (GISH). Plant Science 185–186: 156–160. https://doi.org/10.1016/j.plantsci.2011.10.003
- Kono, Y., Peng, C.I., Oginuma, K., Yang, H.A., Liu, Y. & Chung, K.F. (2022) Cytological study of Begonia sections Platycentrum (Begoniaceae) with chromosome number 2n = 22. Cytologia 87: 255–263. https://doi.org/10.1508/cytologia.87.255
- Kono, Y., Peng, C.I., Oginuma, K., Yang, H.A. & Chung, K.F. (2023) Cytological study of Begonia sect. Platycentrum (Begoniaceae) with chromosome numbers 2n = 24, 26, and 52. Cytologia 88: 365–371. https://doi.org/10.1508/cytologia.88.365
- Lan, Y., Qu, L.W., Xin, H.Y., Gong, H.L., Lei, J.J. & Xi, M.L. (2018) Physical mapping of rDNA and karyotype analysis in Tulipa sinkiangensis and T. schrenkii. Scientia Horticulturae 240: 638–644. https://doi.org/10.1016/j.scienta.2018.06.055
- Liu, B. & Davis, T.M. (2011) Conservation and loss of ribosomal RNA gene sites in diploid and polyploid Fragaria (Rosaceae). BMC Plant Biology 11: 157. https://doi.org/10.1186/1471-2229-11-157
- Marasek-Ciolakowska, A., Ramanna, M.S., ter Laak, W.A. & van Tuyl, J.M. (2010) Genome composition of ‘Elatior’-begonias hybrids analyzed by genomic in situ hybridization. Euphytica 171: 273–282. https://doi.org/10.1007/s10681-009-0057-7
- Moonlight, P.W., Ardi, W.H., Padilla, L.A., Chung, K.F., Fuller, D., Girmansyah, D., Hollands, R., Jara-Muñoz, A., Kiew, R., Leong, W.C., Liu, Y., Mahardika, A., Marasinghe, D.K. Lakmini, O’Connor, M., Peng, C.I, Pérez, Á.J., Phutthai, T., Pullan, M., Rajbhandary, S., Reynel, C., Rubite, R.R., Sang, J., Scherberich, D., Shui, Y.M., Tebbitt, M.C., Thomas, D.C., Wilson, H.P., Zaini, N.H. & Hughes, M. (2018) Dividing and conquering the fastest-growing genus: Towards a natural sectional classification of the mega-diverse genus Begonia (Begoniaceae). Taxon 67 (2): 267–323. https://doi.org/10.12705/672.3
- Nakata, M., Guan, K., Godo, T., Lu, Y. & Li, J. (2003) Cytological studies on Chinese Begonia (Begoniaceae) I. Chromosome numbers of 17 taxa of Begonia collected in 2001 field studies in Yunnan. Bulletin of the Botanic Gardens of Toyama 8: 1–16.
- Neale, S., Goodall-Copestake, W. & Kidner, C.A. (2006) The evolution of diversity in Begonia. In: Teixeira da Silva, J.A. (Ed.) Floriculture, Ornamental and Plant Biotechnology. Global Science books, ISBN 4903313093, Middlesex, UK.
- Oginuma, K. & Peng, C.I (2002) Karyomorphology of Taiwanese Begonia (Begoniaceae): taxonomic implications. Journal of Plant Research 115 (3): 225–235. https://doi.org/10.1007/s102650200028
- Parisod, C., Holderegger, R. & Brochmann, C. (2010) Evolutionary consequences of autopolyploidy. New Phytologist 186 (1): 5–17. https://doi.org/10.1111/j.1469-8137.2009.03142.x
- Peng, C.I. & Ku, S.M. (2009) Begonia × chungii (Begoniaceae), a new natural hybrid in Taiwan. Botanical Studies 50: 241–250. https://doi.org/1817406X-200904-50-2-241-250-a
- Peng, C.I, Liu, Y., Ku, S.M., Kono, Y. & Chung, K.F. (2010) Begonia × breviscapa (Begoniaceae), a new intersectional natural hybrid from limestone areas in Guangxi, China. Botanical Studies 51: 107–117. https://doi.org/1817406X-201001-201004090017-201004090017-107-117
- Peng, C.I, Yang, H.A., Kono, Y., Chung, K.F., Huang, Y.S., Wu, W.H. & Liu, Y. (2013) Novelties in Begonia sect. Coelocentrum: B. longgangensis and B. ferox from limestone areas in Guangxi, China. Botanical Studies 54: 44–52. https://doi.org/10.1186/1999-3110-54-44
- Peng, C.I. & Sue, C.Y. (2000) Begonia × taipeiensis (Begoniaceae), a new natural hybrid in Taiwan. Botanical Bulletin of Academia Sinica 41: 151–158.
- Qu, M., Zhang, L., Li, K.,Sun, J., Li, Z. & Han, Y. (2021) Karyotypic stability of Fragaria (strawberry) species revealed by cross-species chromosome painting. Chromosome Research 29: 285–300. https://doi.org/10.1007/s10577-021-09666-1
- Schwarzacher, T., Leitch, A.R., Bennett, M.D. & Heslop-Harrison, J.S. (1989) In situ localization of parental genomes in a wide hybrid. Annals of Botany 64: 315–324. https://doi.org/42764348
- Shui, Y.M. & Huang, S.H. (1999) Notes on the Genus Begonia from Yunnan. Acta Botanica Yunnanica 21 (1): 11–23. [In Chinese with English Abstract]
- Sun, J., Su, D., Ma, R., Chen, L., Cao, Q., Li, Z. & Han, Y. (2022) Chromosome painting reveals the genomic structure of three polyploid species of Ipomoea. Genome 65: 331–339. https://doi.org/10.1139/gen-2021-0088
- Taketa, S., Harrison, G.E. & Heslop-Harrison, J.S. (1999) Comparative physical mapping of the 5S and 18S-25S rDNA in nine wild Hordeum species and cytotypes. Theoretical and Applied Genetics 98: 1–9. https://doi.org/10.1007/s001220051033
- Tebbitt, M.C. (2003) Notes on South Asian Begonia (Begoniaceae). Edinburgh Journal of Botany 60 (1): 1–9.
- Tebbitt, M.C. (2005) Begonias: Cultivation, Identification and Natural History. Timber Press, Portland, Oregon.
- Tebbitt, M.C., Lowe-Forrest, L., Santoriello, A., Clement, W.L. & Swensen, S.M. (2006) Phylogenetic relationships of Asian Begonia, with an emphasis on the evolution of rain-ballist and animal dispersal mechanisms in sections Platycentrum, Sphenanthera and Leprosae. Systematic Botany 31 (2): 327–336. https://doi.org/10.1600/036364406777585784
- Tian, D.K., Xiao, Y., Tong, Y., Fu, N.F., Liu, Q.Q. & Li, C. (2018) Diversity and conservation of Chinese wild begonias. Plant Diversity 40 (3): 75–90. https://doi.org/10.1016/j.pld.2018.06.002
- Tian, D.K., Li, C., Tong, Y., Fu, N.F. & Wu, R.J. (2017) Occurrence and characteristics of natural hybridization of Begonia in China. Biodiversity Science 25: 654e674. [ In Chinese with English Abstract] https://doi.org/10.17520/biods.2017050
- Wei, Y.F., Jiang, X.H., Song, R. & She, C.W. (2024) Molecular cytogenetic characterization of 9 populations of four species in the genus Polygonatum (Asparagaceae). Comparative Cytogenetics 18: 73–95. https://doi.org/10.3897/compcytogen.17.122399
- Weiss-Schneeweiss, H., Stuessy, T.F., Siljak-Yakovlev, S., Baeza, C.M. & Parker, J. (2003) Karyotype evolution in South American species of Hypochaeris (Asteraceae, Lactuceae). Plant Systematics and Evolution 241: 171–184. https://doi.org/10.1007/s00606-003-0026-x
- Xiao, Y., Li, X.J., Jiang, X.L., Li, C., Li, X.P., Li, W.P. & Tian, D.K. (2023) Spatial genetic patterns and distribution dynamics of Begonia grandis (Begoniaceae), a widespread herbaceous species in China. Frontiers in Plant Science 14: 1178245. https://doi.org/10.3389/fpls.2023.1178245
- Zhu, X.Z., Hu, X.H., Huang, S.X., Lu, Q.F. & Liao, T. (2022) Characterization of the complete chloroplast genome of Begonia handelii. Mitochondrial DNA Part B 7: 2031–2034. https://doi.org/10.1080/23802359.2022.2119107
- Zoller, J.F., Yang, Y., Herrmann, R.G. & Hohmann, U. (2001) Comparative genomic in situ hybridization (cGISH) analysis on plant chromosomes revealed by labelled Arabidopsis DNA. Chromosome Research 9: 357–375. https://doi.org/10.1023/a:1016767100766