In Vitro Screening of Different Potato Genotypes for Salinity Tolerance

Abstract

In vitro screening of several potato genotypes (29 cultivars and lines) to salinity stress was conducted. Single node explants were evaluated on the basis of their growth, microtuberization and biochemical analysis under different concentrations of salt (NaCl) stress. In most cases, increasing NaCl in the tissue culture medium resulted in reduction in plantlet growth, rooting and microtuberization potential in varying degrees, depending on the cultivar. Some genotypes such as Oceania, 97f-267 and Picasso produced higher number of microtuber under 150 mM NaCl than control. Generally, 97f-267, Oceania and Universa genotypes were ranked among salt tolerant, while Nicola, Safran, Diamant were ranked as moderate and Elodi, Triomph, Marabel, Bolista and 99-981 were ranked as salt sensitive based on morphological characters. Photosynthetic pigments decreased under salt stress, however, Universa and Safran maintained higher chlorophyll content under salt conditions (100 mM NaCl) comparing with control (0.0 mM NaCl) plantlets. Also, Universa and Safran accumulated more proline and free amino acids under stress treatment comparing with control, than other tested genotypes. The activities of antioxidant enzymes were different among potato genotypes. In this respect, Universa and Safran had higher catalase (CAT) activity under salt stress (100 mM NaCl) than control treatment (0.0 mM NaCl), however, superoxide dismutase (SOD) activity was not good indicator for salinity tolerance in the tested potato genotypes.