The Effect of Various Salts on Multiplication of Nicotiana tabacum L. Shoot Cultures of Different Na 2SO 4 Tolerance

Abstract

Summary Na2SO4-normal (N), Na2SO4-tolerant (T) and Na2SO4-sensitive (S) shoot cultures of Nicotiana tabacum L. cv. Wisconsin 38 maintained on Na2SO4-free medium for more than 8 subcultures, were grown on medium supplemented with various sulfates and chlorides. Concentrations of 140 or 280 mM were used in tests of shoot proliferation, and 70 or 140 mM for rooting. Shoot growth of all 3 tolerance categories and a control decreased substantially in the presence of salts, but the T shoots exhibited the highest multiplication rate. T shoots also exhibited the highest percent rooting, particularly in the presence of sulphates and produced the most abundant roots. The S shoots showed the lowest shoot multiplication rate, shortest shoot length, lowest percent rooting, lowest root number and shortest root length in response to salts. The differences between other categories were not significant. Of all salts tested, chloride salts were generally less inhibitory to shoot proliferation and rooting than sulfate salts, among which K2SO4 was the most inhibitory to shoot growth.