Cytogenetic modifications in young plantlets exposed to low power microwaves

M.Răcuciu1, D.E. Creangă2, Fl. M. Tufescu2

1 University Lucian Blaga, Faculty of Science, Physics Department, Dr.I.Ratiu Street, No.5-7, 550012, Sibiu, Romania, mracuciu@yahoo.com
2 University Al. I. Cuza, Faculty of Physics, 11A Blvd. Copou, Iasi, Romania

The low power microwaves influence on the cell proliferation as well as the putative mutagen effects of microwave exposure in cereals has been investigated. Zea mays seeds, having a uniform genophond, have been exposed to low power microwaves for different time intervals. Microwaves with a frequency of 9.75 GHz have been delivered from the horn antenna microwave generator, based on an IMPATT diode. Exposure was carried out for different time durations: from 5h, 8h, 14h, 24h and 64 hours. Plant germination occurred on porous paper support, in darkness and closed Petri dishes, environmental conditions being kept under peer control, temperature and moisture levels being 24 Celsius degrees and respectively 98%. Aliquots from the of 2-3 day old root meristeme of the germinated seeds were taken to prepare microscope slides following squash technique. Microscope investigation was finalized in two biological parameter evaluations: mitotic index and chromosomal aberration index. Mitotic index is able to give the percentage of dividing cells in every sample while chromosomal aberration index represents the sum of aberrant cell divisions. The effects of low power microwaves on the mitotic activity and chromosomal aberration index have been analyzed. Our results show that different types of chromosomal aberrations appeared within the dividing cells: retard chromosomes in anaphase and telophase; chromosomal fragment in anaphase, inter-chromatin bridges in anaphase and residual micronucleus in interphases Graphical analysis of total chromosomal aberrations in samples and controls was carried out and discussed in function of microwave exposure times.

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