Root Architecture and Productivity of Three Grass Species under Salt Stress

Abstract

Salinity not only directly affects above-ground plant growth and development, but also root system architecture and functioning. The mature root system of grasses composes 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 Puccinelia maritima from habitats with different salinities were screened for salt-induced changes in root architecture. Scans of roots were used to quantify root structural 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 L. perenne and P. 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. Key word: Root system architecture (RSA), salt stress, salinity tolerance, Lolium perenne, Festuca rubra, Puccinellia maritima binnenwerk_v1.indd 54 15/09/2022 19:32 55 Root architecture and productivity of three grass species under salt stress