GERMINATION RESPONSE TO DIFFERING SALINITY LEVELS FOR 18 GRASS SPECIES FROM THE SALINE-ALKALINE GRASSLANDS OF THE SONGNEN PLAIN, CHINA

Abstract

Seed germination responses to salinity differ among grass species. The germination of halophytes in saline substrates is a useful criterion for selecting tolerant plants for restoring saline environments. The salt tolerance of germinating seeds from 18 native grass species that greow in the saline-alkali grasslands of the Songnen Plain in Northeastern China. Was studied The effects of different concentrations of sodium chloride (NaCl) (0-500mM) on the germination of seeds were tested at 28°C using a 12-h photoperiod. The 18 species showed different levels of salt tolerance and were classified into 4 groups. Artemisia scoparia was the most tolerant of high salt concentrations, with high germination rates even at 300mM NaCl (91.1%). This species also had the shortest germination time (T50=0.5 d). Echinochloa crusgalli and Cynanchum chinense were moderately salt tolerant, showing high germination rates (84.7%- 100%) at150-200mM NaCl. Medicago sativa, Suaeda salsa, Herba taraxaci, and Plantago asiatica were the next most tolerant, with germination rates of 56.7%-95.0% at 25-150mM NaCl. The remaining 11 species did not tolerate saline conditions or had generally low germination rates regardless of saline concentration. Because of their high salt tolerance, A. scoparia, E. crusgalli, and C. chinense have the greatest potential and can be used in vegetative restoration of saline soils in the arid and semiarid regions of the Songnen Plain.