THE EFFECT OF POTASSIUM ON GROWTH AND YIELD OF STRAWBERRY (FRAGARIA ANANASSA (DUCHESNE EX WESTON) DUCHESNE EX ROZIER)

摘要

The effect of different concentrations (0.25 mM, 0.5 mM) of Cu2+ on anatomical parameters of leaves and roots wasinvestigated in hydroponically grown five wheat (Triticum aestivum L.) varieties (Kazakhstanskaya rannaya,Kazakhstanskaya-3, Melturn, Kaiyr and Shagala). The results showed that wheat varieties exposed to 0.5 mM Cu2+ exhibitedsignificant alterations in anatomical structure of leaves and roots. The thickness of the upper and lower epidermis, diameterof vascular bundles of leaves of almost all varieties showed a tendency to decrease under copper stress. Our experimentsshowed an activation of defense responses in the root anatomical structure like exodermis thickening in some varieties in thepresence of copper in growth medium as compared to the control. This indicates that copper ions increase the thickness ofexodermis, which reduce the absorption of toxic elements by root cells. Copper stress caused a decrease in the thickness ofthe lower and upper epidermis to varying degrees and reduction in the diameter of vascular bundles of wheat leaves. Copperstress caused a reduction in endodermis thickness thereby decreasing the diameter of the central cylinder of wheat roots.