STIMULATION OF SHOOT REGENERATION FROM JUTE COTYLEDONS CULTURED WITH NONIONIC SURFACTANTS AND RELATIONSHIP TO PHYSICOCHEMICAL PROPERTIES

The effects have been studied of the non-ionic surfactants, Pluronic F -68, Tween 20 or Triton X-100, on shoot regeneration from cultured jut e (Corchorus capsularis L.) cotyledons with attached petioles. This gr oup of non-ionic surfactants was selected in order to determine a poss ible relationship between the physico-chemical properties of individua l compounds and their observable effects on plant morphogenesis in cul tured jute cotyledons. Supplementation of culture medium with 0.001-0. 5% (w/v) Pluronic F-68 increased the mean percentage of cotyledons pro ducing shoots and the mean number of shoots/cotyledon, with maximal re sponses at 0.5% (w/v). By contrast, Tween 20 produced maximal effects at 0.001% (v/v), with inhibition of shoot formation at 0.5% (v/v). In both cases, phenotypically normal plants were recovered which could be grown to maturity. Culture of cotyledons with 0.001% (v/v) Triton X-1 00 similarly increased both the percentage of cotyledons producing sho ots and the number of shoots/cotyledon. However, these shoots did not develop into mature plants. Additionally, shoots did not regenerate fr om cotyledons cultured with Triton at 0.01-0.5% (v/v). These results d emonstrate that there is an apparent relationship between the hydrophi lic-hydrophobic (HLB) balance of surfactants which determine their cel l permeabilising properties and consequently, their effects on morphog enesis.