الفهرس 
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Abstract
The present study was mainly aimed to evaluate the cytotoxicity and genotoxicity in soybean treated with fusilade and sencor herbicides. Also,to investigate the effects of these herbicides on anatomical and ultrastructure features of soybean leaves.Three different concentrations (recommended dose-lower than recommended dose- higher than recommended dose) were prepared from each herbicide.For fusilade,the concentrations were (4.2, 12.5 and 20.8 ml/L) while for sencor, the concentrations were (1.6, 2.5 and 3.3 g/L).For cytotoxicity and genotoxicity assay,the majority of the treatments were found to induce variations in mitotic index,phase index and total abnormalities of soybean in the treatments than that of the control.The fusilade had a marked mitodepressive action while sencor had a mitopromotor action on mitosis.For genotoxicity determination,both herbicides produced a large number of chromosomal aberrations in soybean root tip cells such as:disturbed,non-congression,oblique,stickiness,polyploidy and two groups at metaphase stage; late separation,diagonal,bridge,laggard and disturbed at anaphase;late separation,diagonal,bridge and laggard at telophase stage.For light microscopic study,both herbicides caused variations in all measured anatomical parameters such as: leaf thickness,thickness of palisade and spongy parenchyma,thickness of upper and lower epidermis with fusilade and sencor (Post-emergence application) induced reduction in leaf thickness while sencor (Pre-emergence application) caused an increase in leaf thickness of soybean seedlings.For scanning electron microscopic study,treatment of soybean seedling with fusilade and sencor herbicides induced alterations in leaf surface features such as cuticle,epicuticular wax, trichomes and stomata. For transmission electron microscopic study,both herbicides induced alterations in ultrastructure of soybean leaf mesophyll cells.Both herbicides caused changes in number of mitochondria,vacuoles,chloroplast per cell and number of starch grain per chloroplast. Number of plastoglobules within chloroplast was increased in response to both herbicides. Treatment of soybean seedlings with fusilade and sencor herbicides resulted in the appearance of unknown electron- dense bodies inside vacuoles.