Effects of plant growth promoting rhizobacteria and seed priming by salicylic acid on seed germination ceriteria of okra (Abelmoschus esculentus L. Basenti) under different temperatures

In order to investigate the effects of plant growth promoting rhizobacteria and seed priming by salicylic acid on germination and seedling growth charecteristic of okra (Abelmoschus esculentus L Basenti.) in different temperatures an experiment was conducted as factorial layout based on a completely randomized design with four replications at laboratory of the Postharvest Physiology, College of Agriculture, Mohaghegh Ardabili University during 2014. Treatments consisted four temperatures ( 10, 15, 20 and 25°C) and different strains of Pseudomonas putida (1, 10, 19 and 150), Pseudomonas fluorescence (69, 159), combined treatment (10 159 strains) and control (without inoculation) and seed priming with five concentrations of salicylic acid (0, 0.05, 0.1, 0.5, and 1 mM). Result indicated that by decreasing temperature, germination and seedling growth parameters of Okra seeds were reduced and the best temperature for seed germination was observed in 25 °C. On the other hand, inoculation with plant growth promoting rhizobacteria led to significant increase in germination characteristic of okra seeds under different temperature regims such as stem length, seedling height, seedling dry weight, seedling vigor indices. Pseudomonas putida strain 150 and 69 strain of Pseudomonas fluorescent had the greatest effect on germination characteristics of okra seeds under low temperature compared to control. Seed priming by salicylic acid increased all germination and seedling growth characteristics such as seed germination percentage, germination rate, radicle and plumule lengths, plumule and seedling dry weights and length and weight vigor indices under low temperature stress. Seed priming with 0.1 and 0.5 mM concentrations of salicylic acid were more efficient for improvement of seed germination and seedling growth parameters under low temperature stress.