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

Genetics and Molecular Biology

Andréa Beatriz Mendes-bonato²  Claudicéia Risso-pascotto²  Maria Suely Pagliarini²  Cacilda Borges Do Valle¹ 

[1] ,Universidade Estadual de Maringá Departamento de Biologia Celular e Genética Maringá PR ,Brazil

关键词: Brachiaria;    forage grass;    interspecific hybridization;    meiotic rhythm;    microsporogenesis;   

DOI  :  10.1590/S1415-47572006000400021

来源: SciELO

【 摘 要 】

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.

【 授权许可】

CC BY   
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