The Effect of Priming and Salinity on Physiological and Chemical Characteristics of Wheat (Triticum aestivum L.)

Abstract

In order to study of the effect of priming and salinity on physiological and chemical characteristics of wheat<br />(Triticum aestivum L.), an experiment was carried out at the Experimental Farm of Shiraz University. Results showed<br />that primed plants significantly reduced its gas exchanges by accelerating senescence under a series of salt stress,<br />which became more serious along with the increasing of salt concentrations, especially at 21 d after anthesis. Under<br />each level of salt stress, dry matter accumulation of primed plants was always higher than the non-primed plants.<br />Primed plants had higher potassium selectivity against sodium than non-primed plants with the former could maintain<br />relatively stable balance of ions, potassium/sodium was found not to be the limited factor for salt tolerant plants, but<br />it was in salt-sensitive plants. Net photosynthesis (Pn) significantly positively correlated with leaf potassium/sodium<br />(K+/Na+), relative water content (RWC), and leaf area duration (P < 0.01). So those four parameters might be ideal<br />criterions of salt tolerance in wheat. In conclusion, salt stresses caused significant declines in growth period of wheat<br />by accelerating leaf senescence at reproductive stage. Primed plants of wheat successfully preserved normal growth<br />by maintaining Pn, K+/Na+, leaf area duration (LAD) and dry matter accumulation (DMA), while non-primed plants<br />decreased considerably in those parameters. The improvement of photosynthesis and related traits in reproductive<br />stage was a key to the growth of wheat under saline conditions.