Cytogenetic activities of the fungicides nimrod and rubigan-4 on root-tip cells of vicia faba L.

الملخص EN

-The two fungicides Nimrod and Rubigan-4, were tested for genotoxicity using root-tip cells of Vicia faba .

In the first experiment lateral roots were treated with different concentrations of the fungicides for different intervals and observations were taken about mitotic index and percen tage of mitotic phases .

Both fungicides acted as mitostatic agents, which reduced the mitotic index in general.

They also altered the percentage of mitotic phases .

A recovery experiment was conducted using the treatment that gave the lowest mitotic index in each fungicide.

It appeared that the fungicide Rubigan-4 had a more permanent effect on reducing the mitotic index, that stayed even after 96 hours of recovery.

Nimrod increased mitotic index after 48 and 96 hours significantly.

Both fungicides showed a permanent effect on spindle formation ending up with low frequency of anal telophase.

In the third experiment, DNA content of root tip cells was estimated calorimetrically using the diphenylamine procedure.

No significant difference was noticed between control and the roots treated with Nimrod .

Rubigan-4 showed significant increase in DNA content especially when used at high concentrations, indicating that the fungicide arrested cells in interphase stage, (5) period ending up with low mitotic index and high DNA content.