A comparison of hydroponic and soil-based screening methods to identify salt tolerance in the field in barley

Abstract

Success in breeding crops for yield and other quantitative traits depends on the use of methods to evaluate genotypes accurately under field conditions. Although many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. In this study, the salt tolerance, ion concentrations, and accumulation of compatible solutes of genotypes of barley with a range of putative salt tolerance were investigated using three growing conditions (hydroponics, soil in pots, and natural saline field). Initially, 60 genotypes of barley were screened for their salt tolerance and uptake of Na+, Cl–, and K+ at 150 mM NaCl and, based on this, a subset of 15 genotypes was selected for testing in pots and in the field. Expression of salt tolerance in saline solution culture was not a reliable indicator of the differences in salt tolerance between barley plants that were evident in saline soil-based comparisons. Significant correlations were observed in the rankings of genotypes on the basis of their grain yield production at a moderately saline field site and their relative shoot growth in pots at ECe 7.2 [Spearman’s rank correlation (rs)=0.79] and ECe 15.3 (rs=0.82) and the crucial parameter of leaf Na+ (rs=0.72) and Cl– (rs=0.82) concentrations at ECe 7.2 dS m−1. This work has established screening procedures that correlated well with grain yield at sites with moderate levels of soil salinity. This study also showed that both salt exclusion and osmotic tolerance are involved in salt tolerance and that the relative importance of these traits may differ with the severity of the salt stress. In soil, ion exclusion tended to be more important at low to moderate levels of stress but osmotic stress became more important at higher stress levels. Salt exclusion coupled with a synthesis of organic solutes were shown to be important components of salt tolerance in the tolerant genotypes and further field tests of these plants under stress conditions will help to verify their potential utility in crop-improvement programmes.

A Quantitative Profiling Method of Phytohormones and Other Metabolites Applied to Barley Roots Subjected to Salinity Stress

“…Hindmarsh is a currently grown commercial Australian food variety well suited for low to medium rainfall environments with high yield potential. Our ranking results are in accordance with previous studies ( Table 5 , Supplementary Table 2) (Tavakkoli et al, 2012; Kamboj et al, 2015), with the exception of Mundah, which performed particularly poorly in our study exhibiting strong decreases in RL after salinity stress. It should be noted that Hindmarsh is a semi-dwarf barley with a shorter plant height compared to barley varieties not containing the semi-dwarfing gene (Russell et al, 2008; Jia et al, 2016).…”

“…Six varieties of barley ( Hordeum vulgare L.) were selected based on their importance for production, commercially relevant traits and salt tolerant abilities (Tavakkoli et al, 2012; Kamboj et al, 2015). The following Australian barley varieties were chosen: the malting varieties Clipper, Flagship, and Vlamingh, the food variety Hindmarsh, the feed variety Mundah; and the landrace variety Sahara 3771 (Algeria, North Africa).…”

Linking waterlogging tolerance with Mn2+ toxicity: a case study for barley

“…; Tavakkoli et al . ), including better control of background nutrients, pH and the stress level. Different Mn 2+ concentrations have been used in various studies: in wheat, 0.5 m m Mn 2+ (Moroni et al .…”

Expression analysis of three SERK-like genes in barley under abiotic and biotic stresses

“…The seeds of barley Hua-30 were germinated on wet filter paper, and the seedlings were grown hydroponically in a modified Hoagland's solution described by Tavakkoli et al (2012) at 20-22°C with a photoperiod of 12 h. When the seedlings were at the two-leaf stage, we separated the leaves, stem and roots from the seedings for RNA isolation. To investigate the SERK genes' expression in abiotic stress, Hoagland's solution was changed with addition of 300 mM NaCl as salt stress (Seckin et al 2010), and the barley roots and leaves were collected at 0, 1, 2, 4, 6, 12 and 24 hours after the abiotic treatment for RNA isolation.…”