Tissue culture techniques as a tool to select snapdragon mutants with differential NaCl sensitivity

In order to develop a more efficient screening procedure for the genotype evaluation and improvement of salt tolerance, an implementation of a reliable screening procedure is essential. This study reports effective protocols for in vitro propagation of Antirrhinum majus L., and provids the basis for an efficient genotype screening, using physiological and morphological traits during the salt tolerance experiments. About 400 A. majus mutants were obtained from Leibniz Institute of Plant Genetics and Crop Plant Research (IPK1) in Gatersleben, Germany (http://gbis.ipk-gatersleben.de) and a subset of about 70 was selected according to the morpho-physiological characteristics associated to NaCl tolerance reported in "genetic and genomic database DragonDB" for Antirrhinum majus (Snapdragon) (http://www.antirrhinum.net/). Six lines were then selected using the "root-bending assay" previously described for Arabidopsis, suitably modified for the evaluation of Antirrhinum seedlings. The selected lines were then micropropagated in vitro and the following morphological and physiological parameters were assessed: height, total chlorophyll (a+b), carotenoids, anthocyanins, phenols, and water content, potassium (K), calcium (Ca), sodium (Na) and magnesium (Mg) concentration. The results derived from in vitro culture can be used to predict the responses of plants to the environmental conditions and thus reduce the cost of subsequent conventional whole plant experiments. In conclusion, we were able to identify a couple of mutants that showed a differential response in term of NaCl.