caa a22 4500 445322659 CHVBK 20180317142709.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10681-011-0402-5 doi (NATIONALLICENCE)springer-10.1007/s10681-011-0402-5 Meiotic behavior as a selection tool in the breeding of Brachiaria humidicola (Poaceae) [Elektronische Daten] [Kellen Boldrini, Eleniza de Victor Adamowski, Hugo Message, Vergílio Calisto, Maria Pagliarini, Cacilda Valle] Brachiaria humidicola is a tropical grass that grows in seasonally swampy grasslands in Africa. In Brazil, two apomictic cultivars (2n=54) of this species are widely used as pastures in poorly drained soils. The recent discovery of a sexual polyploid accession (2n=36) in the germplasm collection at the Embrapa Beef Cattle Research Center allowed intraspecific hybridization with the objective of broadening the genetic variability and selection of superior genotypes in this species. Hybridization, however, depends on accessions with the same ploidy level. Cytological analyses of 55 accessions revealed that 19 apomictic accessions also presented 2n=36 chromosomes. Chromosome pairing in hexavalent association at diakinesis and metaphase I suggested that the basic chromosome number for this species is x=6. Cytological analysis revealed abnormalities in variable frequencies in the meiosis of these hexaploid (2n=6x=36) accessions. The most common were those related to irregular chromosome segregation which led to unbalanced gamete formation, but chromosome stickiness was also recorded. These results clearly demonstrate the value of cytogenetics in the choice of genitors and for superior hybrids to be obtained in the breeding of this species. For that both the ploidy level and the frequency of abnormalities need to be considered, besides other favorable agronomic characteristics. Springer Science+Business Media B.V., 2011 Brachiaria humidicola nationallicence Breeding nationallicence Forage grass nationallicence Hybridization nationallicence Meiosis nationallicence Boldrini Kellen Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut de Victor Adamowski Eleniza Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut Message Hugo Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut Calisto Vergílio Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut Pagliarini Maria Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut Valle Cacilda Embrapa Beef Cattle Research Center, Campo Grande, MS, Brazil aut Euphytica Springer Netherlands 182/3(2011-12-01), 317-324 0014-2336 182:3<317 2011 182 10681 https://doi.org/10.1007/s10681-011-0402-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10681-011-0402-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Boldrini Kellen Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut NATIONALLICENCE 700 1- de Victor Adamowski Eleniza Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut NATIONALLICENCE 700 1- Message Hugo Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut NATIONALLICENCE 700 1- Calisto Vergílio Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut NATIONALLICENCE 700 1- Pagliarini Maria Department of Cell Biology and Genetics, State University of Maringá, 87020-900, Maringá, PR, Brazil aut NATIONALLICENCE 700 1- Valle Cacilda Embrapa Beef Cattle Research Center, Campo Grande, MS, Brazil aut NATIONALLICENCE 773 0- Euphytica Springer Netherlands 182/3(2011-12-01), 317-324 0014-2336 182:3<317 2011 182 10681 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer