Study effect of water stress on the germination and seedling growth of three genotypes of rangeland species Agropyron podperae

This study aimed to evaluate the effects of various levels of drought stress on the growth of Agropyron podperae. A factorial experiment in the form of completely randomized design was used to evaluate the effects of four different levels of osmotic potentials resulted from PEG 6000 including 0, -3, -6 and -9 bar on the species seedling condition in hydroponic environment. Three genotypes of Agropyron podperae including Tehran (63), Shiraz (7.5) and Lorestan (11.4) and four water stress levels were used in this experiment. The root, shoot and seedling lengths, root to shoot rate, seedling dry weight, seedling fresh weight, dry to fresh weight rate, sprouting rate and seed health index of the species in the all treatments were measured. The results showed that increasing the drought stress levels resulted to increase the root to shoot rate, seedling dry weight and dry to fresh weight rate of the species, but other measured attributes were reduced significantly. The measured plant attributes changed considerably in the -9 bar treatment. In general, Arak (3755) genotype had better sprouting percentage under the drought condition in compare with the other studied genotypes. The results indicated that the drought stress had significant effects on the seedling length and seed health index of the species.