Virus eradication from some Pelargonium zonale cultivars by meristem-tip culture

On the older leaves ofPelargonium zonale chlorotic rings and flecks are common, especially during spring and fall. From such plants an isometric virus can be isolated that causes local lesions on the leaves ofChenopodium quinoa. An attempt was made to produce symptomless plants, reacting negatively onC. quinoa. Meristem tips on a basal medium supplemented with α-naphthalene acetic acid and coconut milk produced abundant callus, but no plantlets. However, on media containing low concentrations of indole acetic acid and kinetin or benzyl adenine, some plants were produced that fulfilled the above requirements. Those selected on horticultural properties, are considered as valuable mother plants. Of twenty-one cultivars such plants were obtained. They may prove an important contribution to the improvement of theP. zonale industry in the Netherlands.