dynamic evolution of chromosome in subgenus Potamogeton revealed by physical mapping of rDNA loci detection

• Published in: Plant systematics and evolution Vol. 298; no. 6; pp. 1195 - 1210
• Main Authors: Wan, Tao, Zhang, Xiao-lin, Gregan, Juraj, Zhang, Ying, Guo, Pin, Guo, You-hao
• Format: Journal Article
• Language: English
• Published: Vienna Springer-Verlag 01.06.2012; Springer Vienna; Springer Nature B.V
• Subjects: Artificial pollination; asexual reproduction; Biological taxonomies; Biomedical and Life Sciences; Chromosome number; Chromosomes; Diploids; diploidy; Evolution; fluorescence in situ hybridization; Gene mapping; Genetic loci; Genomes; Geographical locations; Hybridity; Hybrids; Interspecific; Interspecific hybridization; Interspecific relationships; Life Sciences; Loci; Mapping; Phylogeny; Physical mapping; Plant Anatomy/Development; Plant Ecology; Plant Sciences; Plant Systematics/Taxonomy/Biogeography; Plants; Ploidies; Pollination; Potamogeton; Ribosomal DNA; SHORT COMMUNICATION; Species; Tetraploidy; Physical mapping of rDNAs; Karyotype evolution; Chromosome evolution; Interspecific hybridization
• ISSN: 0378-2697; 1615-6110; 2199-6881
• DOI: 10.1007/s00606-012-0621-9

In this study, we analyzed 12 species in the subgenus Potamogeton (8 tetraploids and 2 diploids, 2 putative tetraploid hybrids) at the chromosomal level, including counting the chromosome number and physically mapping the rDNA. The extent of variation in the chromosome number and rDNA loci was determined in the Potamogeton species on both the inter- and intra-specific level. Moreover, one of the hybrid sets (P. perfoliatus ♂ × P. wrightii ♀) was picked for performing artificial pollination for producing F1 generation adults and for sequential morphological character analysis and FISH detection. After comparing the parental species and natural hybrids from three different geographic locations, the intraspecific variations of rDNA loci were revealed in sampled plants; in addition, comparisons between artificial F1 and natural hybrids (P. × intortusifolius) showed a rapid change of 45S rDNA loci in response to the interspecific hybridization. We also compared our results concerning rDNA patterns with phylogenetic documents to derive complementary clues to karoytype evolution and interspecific relationships. Based on frequent hybridizations and active clonal reproduction with weak genetic selection, the rDNA chromosomal repatterning, such as the gain or loss of rDNA loci together with rDNA movements, might be one trend of chromosome evolution in this genus.