Chromosomal mutations in Siberian larch (Larix sibirica Ledeb.) on Taimyr Peninsula

Chromosome characterization of two varieties of Mangifera indica L.¹

“…It can also be induced by chemical mutagens as MMS or DMS, for instance, in rice (REDDI; REDDI, 1985), or by gamma ray irradiation in grass pea (KUMAR; TRIPATHI, 2007). It was also observed in tree populations growing in an industrial region with the emission of air pollutants and in some cases, strengthened by environmental atypical changes, such as drought (VOSTRIKOVA; BUTORINA, 2006, SEDEL'NIKOVA; PIMENOV, 2007). The causes for the persistence are not clear and the regulation of nucleolus assembly and disassembly is controlled by many proteins in a complex cascade of events (EMMOTT; HISCOX 2009); the understanding of the persistence of nucleolus phenomenon during mitosis calls for more studies at the molecular level.…”

Influence of a Heavy-Metal-Polluted Environment on Viola tricolor Genome Size and Chromosome Number

“…Regardless of the two evolutionary pathways, the disturbed male and female meiosis, some abnormalities in female and male gametophyte development (Słomka et al, 2010(Słomka et al, , 2011c, the variability of chromosome numbers and disturbances in mitosis (this paper) in plants from non-metallicolous sites suggest that this species is still in the process of stabilization. In adverse environmental conditions, plant species with a relatively unstable karyotype may be favored by their ability to change rapidly (Coulaud et al, 1999;Nkongolo et al, 2001;Sedel'nikova and Pimenov, 2007). Many data suggest that such unstable species are at an advantage in adverse heterogeneous environmental conditions (Degenhardt et al, 2005;Seehausen et al, 2008).…”

“…Many data suggest that such unstable species are at an advantage in adverse heterogeneous environmental conditions (Degenhardt et al, 2005;Seehausen et al, 2008). In several plant species with flexible genomes growing in the presence of heavy metals (e.g., Larix sibirica, Armeria maritima, Deschampsia cespitosa) the frequency of different aberrations (e.g., links between nonhomologous chromosomes, vagrant chromosomes, extra constrictions, fragile chromosomes) was markedly higher than in plants from non-contaminated sites (Coulaud et al, 1999;Nkongolo et al, 2001;Sedel'nikova and Pimenov, 2007).…”

“…As heavy metals disturb the cell cycle and cause mutations (Coulaud et al, 1999;Nkongolo et al, 2001;Rayburn and Wetzel, 2002;Sedel'nikova and Pimenov, 2007), they may effect changes in (1) chromosome number (aneuploidy, polyploidy), (2) chromosome structure and (3) ontogeny (endomitosis, endoreduplication) (Jones, 1978;Bayliss, 1980;D'Amato, 1991;Stace, 1991). Those are usually easy to catch with cytological analyses (e.g., Sedel'nikova and Pimenov, 2007) and DNA content measurements (e.g., Rayburn and Wetzel, 2002).…”

“…Those are usually easy to catch with cytological analyses (e.g., Sedel'nikova and Pimenov, 2007) and DNA content measurements (e.g., Rayburn and Wetzel, 2002). Points particularly vulnerable to chromosome breakage are the centromere, secondary constriction and sites with weak chromatin condensation (Jones, 1978;Lee and Philips, 1988;Coulaud et al, 1999).…”