Adventitious regeneration in root culture of a selection of Pelargonium X hortorum cultivars: An assessment of caulogenic potential and genetic stability

Root expiants from twenty two Pelargonium x hortorum FI hybrids were assessed for their caulogenic potential in vitro in response to media containing 4.4 gl^-1 Murashige and Skoog (1962) basal medium containing 30 g l^-1 sucrose, 8 g l^-1 agar and varying concentrations of the growth regulators tri-iodobenzoic acid (TIBA) and thidiazuron (TDZ) at pH 5.8. Caulogenic potential varied from zero to five shoots per expiant. Twenty of the FI hybrids produced shoots. At least 50 rooted shoots from the control and root derived population for twenty genotypes were established in vivo and assessed visually for morphological uniformity up to flowering. Visual examination showed no signs of morphological variation with respect to leaf shape, petal shape, flower colour and plant habit except for cvs. Pink Elite and Red Elite. Progeny derived from the latter had 5.5% and 10 % plants, with variable leaf shape, respectively.