Deep cytogenetics analysis reveals meiotic recombination depletion in species of Senecio (Asteraceae)

Authors
Lopez, Mariana Gabriela; Xifreda, Cecilia Carmen; Poggio, Lidia; Wulff, Arturo Federico
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
Background: Senecio is the largest genus in the Asteraceae family growing in all environments around the world. It displays taxonomic and systematical difficulties. Cytogenetic knowledge of this genus is ancient, scarce and mainly restricted to chromosome number records. Results: In this study we analyzed chromosome number, meiotic configuration, bivalent morphology, meiotic behavior and pollen grain stainability on 100 accessions of 27 different polyploid Senecio L. sect Senecio entities. Median, standard deviation and mode were calculated for number and position of chiasmata and meiotic recombination was statistically evaluated. Although high frequency of multivalents and associated meiotic irregularities are expected in high polyploids, bivalents predominance and, consequently, regular meiosis were observed, with normal sporogenesis and high pollen grain stainability. Conclusion: Depletion in the total chiasmata was significant only in some species but the terminal position was preferential in all the entities analyzed, indicating significant reduction in recombination. The regular meiosis observed suggest that intra and intergenomic reorganization process occur quickly and efficiently in this genus. Mechanisms of diploidization, common to all polyploids, are reinforced by the strong reduction in crossing-over rushing polyploids stabilization.
Instituto de Biotecnología
Fil: Lopez, Mariana Gabriela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Citogenética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. INTA. Instituto de Biotecnología; Argentina
Fil: Xifreda, Cecilia Carmen. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina
Fil: Poggio, Lidia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Citogenética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Wulff, Arturo Federico. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Citogenética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Source
Botanical Studies 54 : 20 (2013)
Subject
Senecio
Citogenética
Meiosis
Cromosomas
Genética
Poliploidia
Asteraceae
Cytogenetics
Chromosomes
Genetics
Polyploidy
Access level
Open access
License
Repository
INTA Digital (INTA)
Institution
Instituto Nacional de Tecnología Agropecuaria
OAI Identifier
oai:localhost:20.500.12123/4270