الفهرس 
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Abstract
The present work was carried out to evaluate the cytotoxicity and genotoxicity of two synthetic fungicides (Dithane M-45 and Rizolex T 50%) and two bio-organic fungicides Clean root (derived from Bacillus subtilis), and Blight stop (derived from Trichoderma harzianum) which are commonly used in Egyptian Agriculture. Each fungicide was applied with three doses, and the control treatment. Two biological systems were subjected to the different treatments as a short term battery. The biological systems included one higher plant Vicia faba as well as one microbial strain, S. cerevisiae D7. The obtained results could be summarized as follows:
A. Cytological studies:
A. i. Effect on mitosis:
1. Data obtained from the direct treatment repeated experiments showed that both synthetic and bio-fungicides have lethal effects on all seeds so the recovery treatments were applied to study their effects on mitotic behaviour of Vicia faba parents and their F1 and F2 plants.
2. All of the applied fungicides doses for the different exposure times, i. e., 6, 12 and 24 hours suppressed significantly the mitotic index (MI) values in V. faba root tips of parent plant (seeds).
3. Values of mitotic index (MI) of F1 seeds exhibited slight increasing than those of the parent treatments of both synthetic and bio-fungicides.
4. F2 plants exhibited the lowest mitotic index value of Dithane M-45 treatments
5. The mitotic index values of F1 and F2 plants were insignificantly changed from that of the control plants.
6. It was clearly observed that the treated parent plants with the two synthetic fungicides exhibited significant total percentage of chromosomal aberrations (except treatments of 6h at the lower two concentrations of both Dithane and Rizolex). In general, the percentage of laggards, bridges, fragments, outside chromosome and stickiness were increased by increasing concentrations and duration of treatments.
7. Treating parent plants with the two bio-fungicides showed no significant increase in the percentages of total chromosomal abnormalities relatively to the control treatment.
8. The values of total abnormal cells of F1 and F2 exhibited highly decrease than those of the parent treatments (both synthetic and bio-fungicides).
9. Types of induced abnormalities were lagging chromosomes, Chromatid Bridge during anaphase, chromatin fragments during the different mitotic stages, outside chromatin and chromosome stickiness.
A. ii. Effect on meiosis:
1. There were no significant differences between treated and the control for parent and F1 in chiasma frequency/cell for all used fungicides.
2. The treated parent plants with synthetic fungicides (Dithane and Rizolex) have a significant proportion of abnormal pollen mother cells (PMCs) than those of the control and treated plants with bio-fungicides. However, there were no significant differences between total meiotic aberrations of treated plants with bio-fungicides and that of the control.
4. There was a significant difference of the total abnormal (PMCs) in F1 plants between synthetic fungicides Dithane and Rizolex and that of the control. On contrast there was no significant effects in the percentage of total abnormal PMCs between bio-fungicides Blight Stop and Clean Root and control plants.
5. The observed meiotic abnormal PMCs included uni & multi-valent, laggards, bridges, outside chromosome, stickiness, tripoler cells and micronuclei.
B. Genotoxicity on the tester S. cerevisia D7 strain:
1. The percentages of survivals decreased as the concentration and/or the treatment periods increased at all tested treatments.
2. The Blight stop (Trichoderma filtrate) with the used concentrations could not induce any convertants or revertants.
3. All of Clean root, Dithane M-45 and Rizolex T 50% doses induced converted colonies in S. cerevisiae D7 stain.
4. None of the tested fungicides doses induced S. cerevisiae D7 reverted colonies except the Dithane treatment.
from the cytological and genetical points of view, results suggested that the use of bio-fungicides as an alternative agricultural material of the synthetic pesticides may be more safety.