• germination
• Lepidium peruvianum
• maca
• salinity
• stress

Abstract
Soil salinization has often been described as a real problem that modern agriculture has to face in order to comply with the urgency of feeding the world’s growing population. Maca is a peruvian plant species of narrow distribution that produce an edible and highly nourishing tuber, with pharmacological proprieties as well. Literature about this species is scarce. In this work, the effects of salinity on seed germination, growth, physiology, and biochemistry of yellow maca (Lepidium peruvianum) were investigated for the first time, with the aim of establishing traits, which can provide a basis for further investigation on this plant. The study was conducted under controlled environment. Maca seeds and plants were subjected to five concentrations of NaCl solutions: 0 (control), 50mM, 100mM, 200mM, 300mM. Germination percentage, growth (root length, fresh weight and dry weight), water content, soluble sugars, ions and pigments content were determined. At the same time, these analyses have been carried on with same concentration of mannitol, in order to compare salinity effects with osmotic ones. All physiological parameters assayed show to be affected differentially depending on NaCl or mannitol treatments. In particular, 50 and 100 mM NaCl treatment generally don’t affect severely the plant, while higher concentrations dramatically affect all parameters. This clustered distribution appears to be different from those obtained in mannitol treatments that instead affect physiological plant responses in a dose-dependent way.