Effect of Seed Priming and Mycorrhiza on Some Physiological Characteristics, Yield and Yield Components of Wheat under Salt Stress Conditions

In order to evaluate the effect of seed priming and inoculation of two mycorrhizal species on a number of physiological characteristics, yield and yield components of a wheat cultivar (Parsi) in salinity stress conditions, an experiment was conducted as a split-plot factorial based on a randomized complete block design with three replications in the years 2014-15 and 2015-16 at Isfahan Jihad Training Center. The experimental factors consisted of two irrigation treatments with saline water (electrical conductivity of 3 and 11 dS/m) in the main plots, and three levels of Glomus species (G. intraradices, G. mosseae and non-application) and two seed priming treatments (hydroprimed seeds as on-farm priming and non-primed seeds) were placed in the sub plots as a factorial. The combined analysis showed that salinity stress affected many of the measured traits and mycorrhiza application reduced the negative effects of salt stress on sodium accumulation in shoots, SPAD index, and spikes/plant and 1000-seed weight and had significant interaction with salinity stress. Application of G. intraradices reduced the sodium content of leaves in salinity conditions by 17% in comparison with G. mosseae. Also, mycorrhizal inoculation increased leaf proline by 20% and seed priming decreased this osmolyte by 18.5%. Application of G. mosseae species led to a 15.6% increase in the activity of superoxide dismutase in comparison with non-inoculation treatment and produced higher grain yield (9.5%). In this study, seed priming had no effect on yield and its components, except in the second year of the experiment when priming under inoculation with G. intraradices resulted in a 23% increase in the spikes/plant compared to non-priming. Another result was an increase of 14.5% of the harvest index due to the mycorrhizal inoculation. In general, the application of mycorrhiza in saline conditions is beneficial to the wheat plants, but the use of seed priming can only be useful if it is accompanied with the inoculation of wheat by the G. intraradices.