Effect of Hydro and Osmo-Priming in Combination with GA3 and KNO3 on Seed Germination of Dodonaeaviscosaunder Salinity Conditions

Dodonaeaviscosa is an evergreen and perennial shrub which distributed widely in warm regions throughout the world. Untreated seeds germinatewell, but to shorten germination, seeds werefloated in hot water for 30 seconds, then cooled down rapidly. In addition, scarification as pre-treatment and dipping the seed in boiling water improve seed germination. Under salinity,the level of abscisic acid increases more than gibberellic acid which prevents seeds germination. Accumulation of Na and Cl- ions can lead to changes in water status in plant tissues and creating a series of second stress, such as oxidative stress. In priming, seeds are authorized to absorb some water, sothat, the early stages of germination are donewithout root emerging. The country of Iran and especiallyKhozestan province is located in arid and semi-arid region of the world, sounder such conditionand dueto high temperature and low rainfall, and salinity of water sources and media, D.viscosasexual reproduction is suffered by serious challenges. Consequently,the objective of this study was to investigate the effectsof hydro and osmo-priming in combining withgibberellic acid and potassium nitrate on seed germination of D.viscosaunder salinity stress.
Two experiments in 2010 wereconducted separately and consecutively in completely randomized design with five treatments and four replications in the plant propagation laboratory of faculty of Agriculture, ShahidChamran University of Ahvaz (latitude 31.33° N, longitude 48.69° E, altitude 23 m). In the first experiment, 500 seeds were selected from seed lot, and were disinfectedwith sodium hypochlorite 2.5%, afterwards, divided into five categories (each category consisted of 100 seeds in four replicates) and were treated as : 1) Osmo-priming with gibberellic acid 50 and 100 mg.l-1 and potassium nitrate 0.5 and 1 % for 12 h. 2) hydro-primed with distilled water (as control) for 12 h. A week later second experiment wascarried out (with 500 seeds from some initial seedlot) base of the best result obtained in the first experiment to study theeffects of salinityonseed germination. Seeds weretreated withgibberellic acid(50 mg.l-1)for 12 h. During germination, seeds were irrigated with different levels of salinity, including 0.0 (distilled water as control), 3, 6, 9 and 12 ds.m-1using NaCl salt (as halopriming). Analysis of data (ANOVA) wasperformed by procedure within thestatistical software MSTAT-C and means were separated by multiple-rangetest of Duncan’s at (p