The Efficiency of Different Priming Agents for Improving Germination and Early Seedling Growth of Local Tunisian Barley under Salinity Stress.

Rim Ben Youssef,Nadia Boukari,Nahida Jelali,Francisco Perez Alfocea,Cristina Martinez,Alfonso Albacete,Chedly Abdelly

doi:10.3390/plants10112264

Abstract

The current work aimed to investigate the effect of seed priming with different agents (CaCl2, KCl, and KNO3) on germination and seedling establishment in seeds of the barley species of both Hordeum vulgare (L. Manel) and Hordeum maritimum germinated with three salt concentrations (0, 100, and 200 mM NaCl). The results showed that under unprimed conditions, salt stress significantly reduced the final germination rate, the mean daily germination, and the seedling length and dry weight. It led to a decrease in the essential nutrient content (iron, calcium, magnesium, and potassium) against an increase in sodium level in both of the barley species. Moreover, this environmental constraint provoked a membrane injury caused by a considerable increase in electrolyte leakage and the malondialdehyde content (MDA). Data analysis proved that seed priming with CaCl2, KCl, and KNO3 was an effective method for alleviating barley seed germination caused by salt stress to varying degrees. Different priming treatments clearly stimulated germination parameters and the essential nutrient concentration, in addition to increasing the seedling growth rate. The application of seed priming reduced the accumulation of sodium ions and mitigated the oxidative stress of seeds caused by salt. This mitigation was traduced by the maintenance of low levels of MDA and electrolyte leakage. We conclude that the priming agents can be classed into three ranges based on their efficacy on the different parameters analyzed; CaCl2 was placed in the first range, followed closely by KNO3, while the least effective was KCl, which placed in the third range.

Highlights

Germination, as the most crucial process in the crop life cycle, is regulated by both internal and external factors
CaCl2 seemed to be the most efficient protector, causing an increase of 26% and 61% in FG% in H. maritimum and H. vulgare
Manel), respectively, when the seeds were exposed to 200 mM NaCl compared with their unprimed equivalents, while in the absence of priming treatments, seed germination was clearly affected by the salinity

Summary

Introduction

Germination, as the most crucial process in the crop life cycle, is regulated by both internal and external factors. Salinity is among the most harmful environmental stresses that restrict agricultural productivity [2]. It greatly limits crop yield in semi-arid and arid regions, and affects approximately 397 million hectares of fertile soil in the world [3]. Under such an environmental stressor, seedling growth and the productivity of several crops are affected due to water limitations and ion imbalance [4,5]

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