Cytogenetic evidence for genome elimination during microsporogenesis in interspecific hybrid between Brachiaria ruziziensis and B. brizantha (Poaceae)

Autor: Andréa Beatriz Mendes-Bonato, Claudicéia Risso-Pascotto, Maria Suely Pagliarini, Cacilda Borges do Valle
Jazyk: angličtina
Rok vydání: 2006
Předmět:
Zdroj: Genetics and Molecular Biology, Vol 29, Iss 4, Pp 711-714 (2006)
Druh dokumentu: article
ISSN: 1415-4757
1678-4685
DOI: 10.1590/S1415-47572006000400021
Popis: Microsporogenesis was analyzed in an interspecific hybrid between an artificially tetraploidized sexual accession of Brachiaria ruziziensis (R genome) and a natural apomictic tetraploid accession of B. brizantha (B genome). Chromosomes associated predominantly as bivalents. From this phase to the end of meiosis, chromosomes presented irregular segregation and abnormal arrangement in the metaphase plate. During metaphase I, in 27.8% of meiocytes, bivalents were distributed in two metaphase plates. In anaphase I, two distinct and typical bipolar spindles were formed. In 29.7% of pollen mother cells, one genome did not divide synchronically, with chromosomes lagging behind or not segregating at all. The second division was very irregular, resulting in polyads. Based on previous results from analysis of a triploid hybrid between these species, where the R genome was eliminated by asynchrony during meiosis, it is suggested that the laggard genome in this hybrid also belongs to B. ruziziensis.
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