Cytogenetic evidence for genome elimination during microsporogenesis in interspecific hybrid between Brachiaria ruziziensis and B. brizantha (Poaceae)
Genet. mol. biol
; 29(4): 711-714, 2006. ilus, tab
Article
in En
| LILACS
| ID: lil-450494
Responsible library:
BR26.1
ABSTRACT
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 percent of meiocytes, bivalents were distributed in two metaphase plates. In anaphase I, two distinct and typical bipolar spindles were formed. In 29.7 percent 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.
Full text:
1
Index:
LILACS
Main subject:
Brachiaria
/
Poaceae
/
Meiosis
Language:
En
Journal:
Genet. mol. biol
Journal subject:
GENETICA
Year:
2006
Type:
Article