EVALUATION OF THE CYTOGENETIC EFFECTS PRODUCED BY BOTRYTIS ALLII FUNGUS TO ALLIUM CEPA
The purpose of this paper was to evaluate the cytological effects produced by Botrytis allii fungus (gray rottenness) on the meristematic cells of onion (Allium cepa). In case of the samples studied (onion bulbs affected by the disease, together with a healthy control), the following cytogenetic characteristics were analysed: the mitotic index, the frequency of mitosis phases in the roots apex, the frequency and types of chromosomal aberrations and nuclear abnormalities.
After analysing results were found large differences between samples; thus, the mitotic index decreased from 11.88% for the control to 2.24-4.01% for samples affected by Botrytis allii. Also, it has been found the following main types of chromosome aberrations and nuclear abnormalities: sticky and laggard type chromosomes, fragments of chromosomes, as well as cells with nuclear erosion. From this point of view, the frequency of chromosomal aberrations and nuclear abnormalities was significantly higher in the case of variants affected by Botrytis allii, compared to the control variant (1.41% for control variant and 10.43-14.74% for variants affected by Botrytis allii).
The results show that Botrytis allii (gray rottenness) has the ability to cause a large number of mitotic abnormalities to Allium cepa, affecting the growth and development of plants. In addition, the cytogenetic effects of infection with Botrytis allii can probably be similar to those produced by the action of a mutagenic agent.