ASPECTS REGARDING THE MITOTIC ACTIVITY IN SOME VARIETIES OF WHEAT (TRITICUM AESTIVUM) GROWN IN THE EXPERIMENTAL FIELD AT SCDA CARACAL

Wheat has a great importance as a food product, providing a large part of the carbohydrates and proteins needed by humans and representing more than half of the calories consumed by mankind. The nutritional importance of wheat and its beneficial effects on human health have been emphasized in many studies, both in agricultural and medical fields.In the current climate conditions and the predicted changes, as a result of the global warming phenomenon, drought resistance is a priority objective of wheat breeding programs. A decrease in soil water potential due to drought decreases the mitotic activity and rate of leaf expansion.This study presents some results regarding the mitotic activity (MA) in some varieties of wheat (Triticum aestivum) grown in experiences set up at SCDA Caracal (Romania). Water stress caused a decrease of MA in al genotypes and changes in cell wall integrity. The mitotic index (MI) was an efficient index for detecting the mitotic activity deterioration process, which ranged from 9.2 to 17.6%. There was also some alterations of normal mitosis and appearance of some chromosomal and nuclear abnormalities in wheat cells (disorganized cells, chromosome fragmentation, sticky chromosomes, unequal anaphase, ghost nucleus, etc.), with values ranging from 7.15 to 26.08%.These results suggest a reduction of mitotic activity and increase of oxidative stress in wheat under drought conditions.