CYTOLOGICAL CHANGES IN TURKISH DURUM AND BREAD WHEAT GENOTYPES IN RESPONSE TO SALT STRESS

Abstract

Effects of salt stress on root growth, mitotic index, nuclear volume, vacuolization, nucleolar distortion and starch content were investigated in Turkish bread wheat (Triticum aestivum L. cvs. Yildiz - salt sensitive, Dagdas - salt tolerant) and durum wheat (Triticum durum L. cvs. C1252 - salt sensitive, Meramsalt tolerant) genotypes which were treated with 150 mM NaCI over a 6-day period. Salt treatment of wheat seedlings resulted in a decrease in root elongation and cell division in all genotypes at the 48 hours. According to controls, wheat root length decrease was 49% for Dagdas, 53.34% for Yildiz, 25.34% for Meram, 53.68% for C1252 at the 48 h. Mitotic index showed a more significant decrease in sensitive genotypes (1.24% for Yildiz, 0.66% for C1252 compairing to their controls 3.85% and 3.72%, respectively) of bread and durum wheat rather than tolerant ones (2.21% for Dagdas, 1.57% for Meram compairing to their controls 4.12% and 5.88%, respectively) at the 48 h of salt treatment. Calculated nuclear volume of wheat genotypes besides Dagdas showed a decline at the 48 h ranged from 1.57 x 10(5) to 2.13 x 10(5) mu m(3). Vacuolization and nuclear distortion appeared on DAPI-stained preparations. There was a clear reduction in starch content in salt treated genotypes of durum wheat.