Effect of heavy metals on meiosis cell division in Stachys inflata Benth.

Stachys inflata Benth. belonging to Lamiaceae, grows in the vicinity of zinc and lead mine around Zehabad village, Qazvin Province, Iran. The aim of this study is to determine how S. inflata is affected by a long-term exposure to zinc and lead pollutants. The focus, here, is on how the meiotic behaviour of pollen mother cells as well as pollen fertility are affected by heavy metal pollutants. ICP-MS analyses of soil and water samples indicated the presence of lead and zinc in a concentration much higher than the recommended standard. The results revealed that soil and water polluted by heavy metals had a significant impeding effect on the division of PMCs in S. inflata. An elevated meiosis abnormality rate, as well as decreases in meiotic index and in pollen fertility were observed compared to the control. The data indicate that this species is not meiotically stable. In general, the pollen mother cells of specimen grown in polluted soil exhibited an increased incidence of chromosome stickiness, B-chromosomes, chromosome bridges, laggard chromosomes, micronucleus, desynapsis, cytomixis and formation of tripolar and pentapolar cells.