Cytogenetic Effect of Radiation in Seed of Oak (Quercus robur L.) Trees Growing on Sites Contaminated by Chernobyl Fallout

Abstract

The Chernobyl accident was one of the largest man made environmental disasters and had significant consequences for people, animal and plants, particularly on land contaminated by radionuclides. Common oak (Quercus robur L.) is the main forest species on land contaminated by Chernobyl fallout areas in the Voronezh region. Therefore it is very important to know how irradiation of oak trees will affect the quality of oak progeny in future consequently. Cytogenetic characteristics such as mitotic activity, level and spectrum of mitotic disturbances, frequency of the cells with persistent nucleoli in the stages of metaphase, anaphase, telophase and multinuclei in interphase cells were investigated in progeny of common oak (Quercus robur L.) trees subjected to different degrees of radioactive contamination. In progeny growing under the influence of this radioactive contamination we observed variability of such cytogenetic characteristics as mitotic activity. However, the variability of this trait was also connected to fluctuations in the weather. The duration of mitotic stages (which may be connected with disturbance of spindle division formation and absence of cytotomy) also varied. An increase in chromosomal bridges among other types of mitotic abnormalities may be considered a result of increases in the meristematic cells repair activities. Activity of some dormant nucleolus organizer regions was also observed. The level of pathological mitoses increased in particular years and was decreased in others. Thus irradiation induces instability of cytogenetic characteristics in oak progeny that produces a type of "wave kinetics" in the mutation rate. This makes them more sensitive to environmental conditions. Therefore we do not recommend to use the oak seeds collected from irradiated areas for reforestation because undesirable genetic changes may have occurred in them.

Mutation activity of Lonicera caerulea population in an active fault zone (the Altai Mountains)

“…We observed small proportions of abnormal mitoses in samples from the control site in all mitotic phases. This is a result of spontaneous mutations usually associated with plant response to changes in weather conditions (Butorina et al, 2001;Kalaev, Butorina, 2006). However, the significant increase in the proportion of abnormal mitoses in samples from the А-, А+, and E sites is most likely connected with the influence of factors of the geological environment.…”

Cytogenetic response of seed progeny of scots pine to combined anthropogenic pollution in the area of Novolipetsk metallurgical combine

“…В настоящее время в литературе приводится большое количество дан-ных об использовании древесных растений в качестве тест-объектов: пред-ставителей родов лиственных -Populus, Quercus, Betula, Acer и других; хвойных -Pinus, Larix, Picea и Abies (Буторина и др., 2000, 2002; Kalaev, Butorina, 2006;Дружкина, 2007;Калашник, 2008;Квитко, 2009 и др. ).…”

Cytogenetic variability of seed progeny from trees of weeping birch (Betula pendula Roth), growingin different ecological conditions

“…Ранее остаточные ядрышки на стадии метафазы -телофазы митоза в клетках апикальной меристемы корней проростков семян были обнаруже-ны на экологически чистых и загрязненных территориях у березы повислой (Вострикова, 2001; Kalaev, Karpova, 2003; Калаев и др., 2006), у дуба черешчатого (Буторина, Исаков, 1989;Kalaev, Butorina, 2006). Появление оста-точных ядрышек на стадии метафазы -телофазы мито-за свидетельствует об амплификации рибосомальных ге-нов на указанных стадиях (Буторина, Исаков, 1989).…”