Root architecture and productivity of three grass species under salt stress

Salinity not only directly affects above-ground plant growth and development but also root system architecture and functioning. The mature root system of grasses is composed of primary and seminal roots with their laterals and crown roots. The root structure strongly influences the plant's ability to take up water and nutrients, thereby affecting plant health and tolerance to abiotic stress. Three grass species, Lolium perenne, Festuca rubra and Puccinellia maritima from habitats with different salinities, were screened for salt-induced changes in root architecture. Scans of roots were used to quantify root's structural and architectural traits using the RootNav software package. The results show that: 1) salinity affects root system architecture differently in the three grass species studied: in Festuca rubra and Puccinellia maritima salinity promoted primary root growth; 2) seminal root length of Lolium perenne and Puccinellia maritima was stimulated significantly by salinity, whereas in F. rubra no stimulation occurred up to 150 mM NaCl and seminal root length was inhibited at 200 mM; And 3) salinity inhibited lateral root growth in L. perenne, but promoted lateral root growth in both F. rubra and P. maritima