Effect of autoclaving amino acids on in vitro rooting response of wild cherry shoot

Abstract

The effects of L-glutamine, L-glutamic acid, L-asparagine, tryptophan and auxins were studied on the adventitious root growth in wild cherry. Different concentrations of the amino acids were added to the media before autoclaving or by sterile filtration after autoclaving. Root induction was by culturing shoots on MS basal medium with IBA 5.5 μM for 5 days. Induced shoots were transferred to supplemented media and then the number of roots and their elongation were determined after 30 days. The number of developed roots was the same in all conditions tested (nine to ten roots per plantlet). When L-glutamine (1.4 mM) was added before autoclaving, root elongation stopped at 9 mm; but root length reached 48 mm when L-glutamine was added by filtration after autoclaving. When L-glutamic acid (1.4 mM) was added before or after autoclaving, the root lengths were 16 mm and 21 mm, respectively. In the presence of L-asparagine, added before or after autoclaving, the root length attained 47 mm, in both cases. Root elongation was similar when either 5-oxoproline (1.4 mM) was added after autoclaving, or when L-glutamine was added before autoclaving. Without amino acid, root elongation was similar to the results obtained when L-glutamine was added by filtration, or L-asparagine. Therefore, these results indicate that the autoclaving of L-glutamine could produce the same inhibitory effect as 5-oxoproline, which strongly inhibits root elongation in Prunus avium L.