Data/hora: 19/06/2024 15:39:51

Biblioteca(s): 	Embrapa Gado de Corte.	
Data corrente: 	04/12/2023	
Data da última atualização: 	04/12/2023	
Autoria: 	DAMASCENO, A. G.; FERREIRA, M. T. M.; SOARES, I. C.; BARRIOS, S. C. L.; VALLE, C. B. do; TECHIO, V. H.	
Afiliação: 	ANA GABRIELA DAMASCENO, UNIVERSIDADE FEDERAL DE LAVRAS; MARCO TÚLIO MENDES FERREIRA, UNIVERSIDADE FEDERAL DE LAVRAS; ISADORA CARDOSO SOARES, UNIVERSIDADE FEDERAL DE LAVRAS; SANZIO CARVALHO LIMA BARRIOS, CNPGC; CACILDA BORGES DO VALLE, CNPGC; VÂNIA HELENA TECHIO, UNIVERSIDADE FEDERAL DE LAVRAS.	
Título: 	Physical mapping of ribosomal DNA sites and genome size in polyploid series of Urochloa humidicola (Rendle) Morrone & Zuloaga (Poaceae).	
Ano de publicação: 	2023	
Fonte/Imprenta: 	Botany Letters, v. 170, n. 4, p. 634-643, 2023.	
DOI: 	https://doi.org/10.1080/23818107.2023.2192274	
Idioma: 	Inglês	
Notas: 	Published online 27 Mar 2023.	
Conteúdo: 	ABSTRACT - Urochloa humidicola (Rendle) Morrone & Zuloaga is a species native to Africa that grows in tropical regions, especially in sites with temporary flooding. Despite its importance as forage crop, the karyotypic characterization of its cytotypes remains mainly unfinished, and its polyploid origin is unknown. Therefore, cytogenetic studies can provide information about the evolutionary history of species and to characterize the core and reserve collection of the germplasm banks. We performed the karyotype analyses, mapped ribosomal sites, and estimated genome size, confirming three ploidy levels (6×, 7×, and 9×) and one aneuploid accession H031 (2n = 6× = 36 + 1). Karyotypes are symmetrical and the number of 35S and 5S rDNA sites varied between the cytotypes. However, all sites were at terminal and interstitial positions in the chromosomes, respectively, except one chromosome of the aneuploid accession with interstitial colocalization. The polymorphism of the number and distribution of rDNA sites in U. humidicola was confirmed by (i) the variation between and within plants and in metaphases of the same meristem in hexaploids and heptaploids; (ii) the occurrence of rDNA sites in hemizygosis in all accessions, except heptaploids; (iii) the size heteromorphism in some ribosomal sites of homologous chromosomes. The karyotype data and the mapping of ribosomal sites corroborate the proposals of allopolyploidy in U. humidicola and the hybrid origin to the H031 accession.	
Thesagro: 	Banco de Germoplasma; Brachiaria; Capim Urochloa.	
Thesaurus Nal: 	Aneuploidy; Cytotypes; Flow cytometry; Forage crops; Ribosomal DNA.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Gado de Corte (CNPGC)	
Exemplares: 	CNPGC - (17938-1) - UPC - AP - DD -  -  -  - DIS