Cytogenetics of Mimosa bimucronata (DC.) O. Kuntze (Mimosoideae, Leguminosae): chromosome number, polysomaty and meiosis

Abstract

-Chromosome numbers (somatic and/or gametic)

Occurrence and significance of polysomaty in species of Mimosa L.

“…Polysomaty was totally absent in roots of well-grown plants. Similar results were found by Olkoski & Schifino-Wittmann (2011) in M. bimucronata Kuntze, in which polysomaty was restricted to seedling roots, being absent in roots of grown plants and in pollen mother cells.…”

“…In Mimosa, polysomaty has been reported only in root-tip cells of some species by Witkus & Berger (1947), Seijo (1993Seijo ( , 1999, and Olkoski & Schifino-Wittmann (2011). Dahmer et al (2011) reported root-tip polysomaty in 26.5% of the 125 Mimosa accessions analyzed.…”

Unconventional vegetables collected in Brazil: chromosome number and description of nuclear DNA content

“…In relation to the DNA content, even though it tends to remain constant within the species, some exceptions may occur owing to variations in the genome of the species. In many cases, this intraspecific variation is due to chromosome variation, aneuploidy, presence of supernumerary chromosomes, loss or duplication of chromosome segments, and highly repetitive DNA (Navarini et al 2008, Olkoski and Wittmann 2011, Souza-Chies et al 2014). …”

Complex of pollen mother cell and polyad production during microsporogenesis in Hippocratea volubilis (Hippocrateaceae)

“…Meiosis is a sequence of highly coordinated mechanical, physiological and biochemical events and is controlled by a great number of genes, which culminate in gene recombination and the reduction of the number of chromosomes in gametes (Gottschalk and Kaul 1974;Golubovskaya 1979;Sosnikhina et al 2005;Mercier and Grelon 2008). Meiosis during megaand microsporogenesis has been investigated in several plant species (Mendes-Vieira et al 2005;Risso-Pascotto et al 2009;Souza-Kaneshima et al 2010;Vesselina and Mateus-Andrés 2010;Olkoski and Schifino-Wittmann 2011;Papini et al 2011;Godoy et al 2012;Paiva et al 2012).…”

“…No irregularity in this mechanism exists during microsporogenesis leading towards the sterility of pollen grains. However, they remain linked forming polyads with four, eight, 12, 16 and 32 pollen grains (Kenrick and Knox 1982;Olkoski and Schifino-Wittmann 2011). According to Kenrick and Knox (1982), approximately 15% of flower plant families form compound pollen grains or polyads, with special reference to the Leguminosae subfamily Minosoideae, especially the genus Acacia.…”