Título:	Meiotic arrest compromises pollen fertility in an interspecific hybrid between Brachiaria ruziziensis x Brachiaria decumbens (Poaceae: Paniceae).
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.
Ano de publicação:	2007
Referência:	Brazilian Archives of Biology and Technology, v. 50, n. 5, p. 831-837, Sep. 2007.
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
NAL Thesaurus:	Cell fusion Cytogenetics Hybridization Hybrids Microsporogenesis Plant breeding Poaceae Pollination
Digital Object Identifier:	https://doi.org/10.1590/S1516-89132007000500011
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPGC)