PHYSIOLOGICAL AND CYTOGENETICAL EFFECTS OF L-TYROSINE IN ALLIUM CEPA L. EXPOSED TO NaCl STRESS

In the present work, the influences of L-Tyrosine (Tyr) on some physiological and cytogenetical parameters in Allium cepa L., which are germinated in both salt stress and normal conditions were studied. The radicle lengths and radicle numbers of seeds germinated in alone Tyr medium decreased partially compared to with ones the control seeds germinated in distilled water medium, while their germination percentages and fresh weights statistically showed the same values. In addition, the chromosomal aberrations in root meristematic cells in A. cepa seeds germinated in tyrosine alone medium showed a significant rise compared to ones of the control seeds germinated in distilled water. Conversely, salinity stress rather inhibited the seedling growth and seed germination of A. cepa. It also significantly increased the number of chromosomal aberrations and micronuclei, which are the most effective and the simplest an indicator of chromosomal aberrations and cytogenetical damage. But the inhibitive effects of salt on the mitotic activity, seedling growth, seed germination, chromosomal aberration and micronuclei dramatically were alleviated in varying degrees by Tyr treatment.