Data/hora: 09/06/2024 02:35:40

Biblioteca(s): 	Embrapa Gado de Corte.	
Data corrente: 	01/02/2008	
Data da última atualização: 	19/06/2023	
Autoria: 	MENDES-BONATO, A. B.; PAGLIARINI, M. S.; VALLE, C. B. do.	
Afiliação: 	ANDRÉA BEATRIZ MENDES-BONATO, UNIVERSIDADE ESTADUAL DE MARINGÁ; MARIA SUELY PAGLIARINI, UNIVERSIDADE ESTADUAL DE MARINGÁ; CACILDA BORGES DO VALLE, CNPGC.	
Título: 	Meiotic arrest compromises pollen fertility in an interspecific hybrid between Brachiaria ruziziensis x Brachiaria decumbens (Poaceae: Paniceae).	
Ano de publicação: 	2007	
Fonte/Imprenta: 	Brazilian Archives of Biology and Technology, v. 50, n. 5, p. 831-837, Sep. 2007.	
DOI: 	https://doi.org/10.1590/S1516-89132007000500011	
Idioma: 	Inglês	
Conteúdo: 	Microsporogenesis was analyzed in an interspecific hybrid between an artificially tetraploidized sexual accession of Brachiaria ruziziensis (2n=4x=36) and a natural apomictic tetraploid accession of B. decumbens. Syncytes involving a large number of cells were recorded in 15.4% of meiocytes. Meiosis progressed normally in syncytes during prophase I; in metaphase I, however, several nuclei were found fusioned, showing chromosome stickiness and several chromosome fragments. Meiosis was arrested in metaphase I and pycnotic nuclei and micronuclei were formed. Abnormal cytokinesis fractionated the syncyte into abnormal meiotic products that were covered by the pollen wall. Meiocytes in leptotene were recorded in all the slides prepared for both meiotic divisions, and abnormal ?pollen grains? with well-developed pollen wall but containing leptotene nuclei were recorded in 9.18% of grains analyzed. These findings suggested that the meiocytes received the signal to enter meiosis but lacked the signal to proceed beyond leptotene. Despite the absence of the meiotic process, such cells were covered by pollen grain wall. Total pollen sterility resulted from these abnormalities combined with still others observed among meiocytes.	
Thesagro: 	Apomixia; Brachiaria Decumbens; Brachiaria Ruziziensis; Citogenética Vegetal; Esterilidade; Fertilidade; Gramínea Forrageira; Hibridação; Hibrido; Melhoramento Genético Vegetal; Planta Forrageira; Pólen.	
Thesaurus Nal: 	Cell fusion; Cytogenetics; Hybridization; Hybrids; Microsporogenesis; Plant breeding; Poaceae; Pollination.	
Categoria do assunto: 	--	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/doc/326408/1/Meiotic-arrest-compromises-pollen-2007.pdf	
Registro original: 	Embrapa Gado de Corte (CNPGC)	
Exemplares: 	CNPGC - (11729-1) - UPC - AP - -- - 456/08 -  - 456/08 - DIS