SciELO - Scientific Electronic Library Online

 
vol.32 issue2Temporal changes in species composition, diversity, and woody vegetation structure of savannas in the Cerrado-Amazon transition zoneHow to analyze germination of species with empty seeds using contemporary statistical methods? author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Acta Botanica Brasilica

Print version ISSN 0102-3306On-line version ISSN 1677-941X

Abstract

CRUZ, Geyner Alves dos Santos et al. Evidence of genetic differentiation and karyotype evolution of the sedges Cyperus ligularis L. and C. odoratus L. (Cyperaceae). Acta Bot. Bras. [online]. 2018, vol.32, n.2, pp.264-270.  Epub Jan 15, 2018. ISSN 0102-3306.  http://dx.doi.org/10.1590/0102-33062017abb0321.

The taxonomy of Cyperaceae is complex, with genera like Cyperus harboring species complexes. We analyzed the genetic similarity between Cyperus ligularis L. and C. odoratus L. based on DNA fingerprinting and cytogenetics. Significative genetic differentiation (G ST = 0.363) and low gene flow (N m = 0.877) indicated a clear genetic distinction between the two species. Moreover, the clustering analysis showed two distinct genetic groups, suggesting a lack of evidence for hybridization. The phenogram revealed two different lineages, and although all individuals of C. odoratus were collected from plots close to each other, they possessed greater genetic diversity than that observed among individuals of C. ligularis, which were sampled over a wider geographic range. Variation in chromosome number within the two species exhibited the opposite pattern, indicating greater karyotype stability in C. odoratus with 2n = 72 and 2n = 76, while the diploid number for C. ligularis varied from 2n = 66 to 88. The lower genetic variation in C. ligularis may be a result of the founder effect associated with seed dispersion and clonal reproduction. Field observations and analysis of reproductive biology should enrich the understanding of the genetic structure of the investigated populations and their role in successional processes.

Keywords : agmatoploidy; DNA amplification fingerprinting; gene flow; genetic differentiation; hybridization.

        · text in English     · English ( pdf )