Effect of growth retardants, cytokinins and auxins on the multiplication and rooting in vitro of Alstroemeria x hybrida "Juanita"

Abstract

Rhizome cultures of "Jiianita" Polish cultivar of Alstroemeria x hybrida were used to enhance an effectiveness of micropropagation method of new cultivars and selections. The effect of cytokinins (BAP. kinetin and 2iP), auxins (IAA, IBAand NAA), growth retardants (paclobutrazol and flurprimidol alone or in combination were studied in relation to rhizome branching. aerial shoot production and rooting of rhizome. The greatest number of aerial shoots as well as the shortest shoots were observed at the highest BAP concentration (6 mg l<sup>-1</sup>). However, the rhizonies had the poorest rooting ability. BAP at low concentrations combined with kinetin or 2iP also strongly stimulated aerial shoot formation and rhizome branching. Unfortunately. those shoots were of poor qualily. Application of BAP at low concentration with paclobutrazol (0,1-0,5 mg l<sup>-1</sup> ) or flurprimidol (0,01- 1 mg l<sup>-1</sup>) in presence of 1 mg l<sup>-1</sup> NAA resulted in high number of aerial shoots (5-6), reduction of their length and higher rooting ability of the rhizomes. Gr()wth retardants applied with NAA strongly stimulated formation of the roots but suppressed their elongation. Abbreviations: BAP - 6=benzylaminopurine; kinetin - 6-furfurylaminopurine; 2iP - 6-‌γ,γ-dime-thylallylamino]purine); IAA-indole-3-acetic acid; IBA-indole-3-butyric acid; NAA- naphthaleneacetic acid; paclobutrazol (ICI PP-333) - (2-RS,3-RS)-1-(4-chlorophenyl)-4-4-dimethyl-2(1,2,3-triazol-1-yl)-pentan-3-ol flurprimidol (Dowelanco) - α-(1-niethylethy 1-α-[4-trifluro-niethoxy)phenyl]-5-pyridinemethanol.