Abnormal meiosis in tetraploid genotypes of Brachiaria brizantha (Poaceae) induced by colchicine: its implications for breeding

• Authors: A.B. Mendes-Bonato , Felismino M. Ferrari , Kaneshima A.M. Souza , C. Pessim , V. Calisto , M.S. Pagliarini , C.B. Valle_do
• Languages of publication: EN

Abstracts

EN

Meiotic behavior was analyzed in 6 progenies from 3 artificially induced tetraploid (2n = 4x = 36) sexual genotypes (C31, C41, and C48) of the normally apomictic Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., syn. Urochloa brizantha (Hochst. ex A. Rich.) R. Webster. These are key plants to allow intraspecific hybridization of this important forage species, widely used for pastures in the tropics. The percentage of abnormal cells among the plants ranged from 39.8% to 63.2%. In the single plant derived from C48, only the common meiotic abnormalities typical of polyploids were observed, while in plants derived from C31 and C41, a distinct behavior was found. In the majority of cells of those plants, the chromosomes remained scattered in the cytoplasm in the first division, without forming a metaphase plate. This abnormality blocked chromosome movements at anaphase I. Several micronuclei of various sizes were formed and, after the occurrence of an irregular first cytokinesis, the meiocytes progressed normally to the second division, generating polyads with unbalanced microspores. Pollen viability was not correlated with meiotic abnormalities. The importance of these findings to the Brachiaria breeding program is discussed. The sexual progeny of C48 seems most suitable as female parents to be used in intra- and interspecific hybridization.

Keywords

EN

BRACHIARIA BRIZANTHA; BREEDING PROGRAM; COLCHICINE; FORAGE GRASS; MICROSPOROGENESIS; TETRAPLOIDY

Discipline

• GENETICS: GENETICS

• Publisher: Institute of Plant Genetics, Polish Academy of Sciences
• Journal: Journal of Applied Genetics
• Year: 2009
• Volume: 50
• Issue: 2
• Pages: 83-87

Contributors

author

A.B. Mendes-Bonato

author

Felismino M. Ferrari

author

Kaneshima A.M. Souza

author

C. Pessim

author

V. Calisto

author

M.S. Pagliarini

author

C.B. Valle_do

• Document Type: ARTICLE
• Publication order reference: M. Suely Pagliarini, Department of Cell Biology and Genetics, State University of Maringa, 87020-900 Maringa ? Parana, Brazil