Abnormal cytokinesis in microsporogenesis of Brachiaria humidicola (Poaceae: Paniceae)

E.V. Adamowski¹, K.R. Boldrini¹, M.S. Pagliarini¹ and C.B. do Valle^2
1Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, PR, Brasil
²Embrapa Gado de Corte, Campo Grande, MS, Brasil
Corresponding author: M.S. Pagliarini
E-mail: mspagliarini@uem.br

Genet. Mol. Res. 6 (3): 616-621 (2007)
Received June 9, 2007
Accepted July 18, 2007
Published September 30, 2007

ABSTRACT. Microsporogenesis was evaluated in the Brachiaria humidicola collection of the Embrapa Beef Cattle Center, represented by 60 accessions. One accession (H121) presented an abnormal pattern of cytokinesis that had never been reported in this genus. Among 900 meiocytes analyzed in the first division, 10.7% underwent precocious and multiple cytokinesis in metaphase I, fractionating the genome and the cytoplasm into two or more parts. The expected cytokinesis after telophase I did not occur. The abnormal meiocytes from the first division entered the second division but the second cytokinesis after telophase II was also abnormal. Among the 857 meiocytes analyzed in the second division, 10.9% presented abnormal, incomplete or total absence of cytokinesis. Dyads and binucleated microspores were recorded among the meiotic products. The use of this accession in the Embrapa breeding program is compromised.

Key words: Brachiaria humidicola, Breeding program, Cytokinesis, Forage grass, Microsporogenesis