Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae)
Gléia Cristina Laverde Ricci Alice Maria De Souza-Kaneshima Mariana Ferrari Felismino Andrea Beatriz Mendes-Bonato Maria Suely Pagliarini Cacilda Borges Do Valle
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A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented $2n = 18$; 27 accessions, $2n = 36$; and 2 accessions, $2n = 45$ chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.
Gléia Cristina Laverde Ricci1 Alice Maria De Souza-Kaneshima1 Mariana Ferrari Felismino1 Andrea Beatriz Mendes-Bonato1 Maria Suely Pagliarini1 Cacilda Borges Do Valle2
Volume 102, 2023
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