Meiotic Abnormalities and Tetraploidy (by Lead Nitrate) Induced by Heavy Metals (Pb, Cu, Hg, Zn) Helianthus annuus L.

Abstract

Summary Cytological effects of some (Pb, Cu, Zn, Hg) heavy metals were tested on meiotic studies of Helianthus annuus. The used heavy metals did not show much variations in the type of induced abnormal PMCs. The abundant meiotic irregularities stickiness, lagging, bridges, unequal separation, fragmentation etc. were observed. Mercury was the most toxic of all used heavy metals since it produced highest percentage of abnormal PMCs. Lead nitrate is a mutagen which induce tetraploidy.

Spontaneous Occurrence of Meiotic Spindle Abnormalities in 'Long Headed Poppy' (Papaver dubium L.) from Indian Cold Regions

“…These plants which depict the presence of normal 14 bivalents at MI, show irregular spindle behaviour resulting into abnormal anaphases/telophases, irregular microsporogenesis, some pollen malformation and heterogeneous sized pollen grains. Similar abnormal spindle activity leading to high percentage of laggards, bridges, unoriented chromosomes during anaphases/telophases and consequently to tetrads with micronuclei or microcytes and polyads during meiosis is reported in the colchicine induced tetraploid of Physalis pubescens (Lydia and Raja Rao 1982), and of heavy metal induced tetraploid of Helianthus annuus (Srivastava and Srivastava 2004 interspecific Brachiaria hybrid (Mendes-Bonato et al 2006). The present report of spontaneous occurrence of abnormal spindle activity in the PMCs during male meiosis in the tetraploid cytotype of P. dubium is reported for the first time.…”