Behrooz Esmaielpour, Fatemeh Mahmoodi, Roghayeh Nabipour Sanjid, Hamideh Fatemi, Mousa Torabi Gigloo,
Volume 10, Issue 45 (vol. 10, no. 45 2021)
Abstract
In order to evaluate the effect of Inoculation of pea (Pisum sativum L.) mother plants by plant growth promoting rhizobacteria on seed germination and seedling growth traits under Cadmium stress, a factorial experiment based on completely randomized design with four replications was conducted. Experimental treatments included cadmium stress (0, 50 and 100 mg/ l CdCl2) on pea seeds produced from mother plants inoculated by Pseudomonas fluorescence plant growth promoting rhizobacteria strains p15, p25, p32 and without inoculation. Through this experiment, traits such as seed germination and seedling growth characteristics, some biochemical parameters including proline, protein and soluble solid content, photosynthetic pigments content and peroxidase antioxidant enzyme were measured. Results indicated that with increase of cadmium stress, germination percentage and rate, seedling length and dry weight, seedling length index, chlorophyll a, b and total chlorophyll, and soluble solid and protein content of seedlings and peroxidase antioxidant enzyme activity decreased significantly and the highest reduction was occurred at 100 mg/l concentration of cadmium, but cadmium stress increased proline content of seedling and the chlorophyll a/b ratio whereas content of leaves were increased. Meanwhile inoculation of pea plants by Pseudomonas fluorescence bacterial strains led to increases in seed germination and seedling growth parmeters, photosynthetic pigments, proline, protein and soluble solid contents as well as peroxidase antioxidant enzyme activity under cadmium stress condition. Results indicated that Pseudomonas fluorescence p32 strain had the the highest ammeloriated effects on pea seed germination and seedling growth under higher cadmium stress condition. In general the results of this investigation revealed that inoculation of mother plans by Pseudomonas fluorescence plant growth promoting rhizobacteria strains significantly alleviated the deterimental effects of cadmium stress on pea plants via increase in plant hormones responsible in seed germination and seedling growth traits and peroxidase enzyme activity.
