ISSN 1644-0692 www.acta.media.pl Acta Sci. Pol. Hortorum Cultus, 15(1) 2016, 123-134 RESPONSE OF Ornithogalum saundersiae BAK. TO SALINITY STRESS Piotr Salachna, Agnieszka Zawadzińska, Cezary Podsiadlo 1 West Pomeranian University of Technology in Szczecin Abstract. Most of the studies on the effects of salinity stress are conducted on ornamental bedding plants and perennials but little is known on flower bulbs response to this stress factor. Ornithogalum saundersiae is an attractive bulbous plant recommended for grow- ing in pots, gardens and green areas. The study conducted in the years 2013–2014 investi- gated the effects of NaCl on the growth, flowering, photosynthetic activity, pigment con- tent, and macro- and micronutrient content in the leaves of O. saundersiae. The plants were grown in pots in a plastic tunnel. NaCl was applied once a week for six weeks at concentration of 100 mM or 200 mM. The salt treatment did not cause chlorosis and did not affect flowering rate and number of inflorescences. The plants exposed to salinity stress had lower fresh weight of leaves, inflorescences and bulbs and their flowering be- gan later than in the control plants. Photosynthesis and transpiration intensity decreased as NaCl concentration increased. The content of chlorophyll and carotenoids in NaCl treated plants was significantly higher than in the control plants. Salinity stress increased the leaf content of nitrogen, potassium, sodium and chlorine and reduced the concentration of cal- cium, zinc and iron. Key words: Giant Chincherinchee, NaCl, gas exchange, mineral content, photosynthetic pig- ments INTRODUCTION The issue of salinity stress in the cultivation of ornamental plants is receiving global attention [Niu and Cabrera 2010, Cassaniti et al. 2013]. When looking for species and cultivars tolerant to salinity, an important criterion is the effect of salt on the plant or- namental value [Zollinger et al. 2007]. Excessive content of Na + and Cl - causes growth and flowering inhibition, leaf discoloration, and the leaf margins become brown and dry, thus lowering the quality of the ornamental plants [Bernstein et al. 1972]. Apart Corresponding author: Piotr Salachna, Department of Horticulture, West Pomeranian University of Technology in Szczecin, ul. Papieża Pawla VI 3, 71-459 Szczecin, Poland, e-mail: piotr.salachna@zut.edu.pl © Copyright by Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie, Lublin 2016