Responses of physiological parameters, grain yield, and grain quality to foliar application of potassium nitrate in two contrasting winter wheat cultivars under salinity stress

Abstract

An experiment was conducted to test whether foliar application of KNO 3 on wheat in the heading stage could reduce salinity-induced injuries, produce high grain yield, and improve grain quality. Salt-resistant DK961 and salt-sensitive JN17 wheat cultivars under 0 or 100 mM-NaCl conditions were foliarly watered with distilled water or a 10 mM-KNO 3 solution. The four treatments included: T 1 (CK 1 ), 0 mM NaCl + distilled water; T 2 , 0 mM NaCl + 10 mM KNO 3 ; T 3 (CK 2 ), 100 mM NaCl + distilled water; T 4 , 100 mM NaCl + 10 mM KNO 3 . The results indicate that there were no differences (p > 0.05) in plant growth, grain yield, and grain quality between T 2 and T 1 in both cultivars, but these response variables were significantly lower in T 3 than in T 1 . K + : Na + ratio, chlorophyll content, photosynthetic capacity, grain yield, flour yield, water absorbance, ash content, dough-development time and dough-stability time were significantly higher in T 4 than in T 3 , while protein concentration, wet-gluten concentration, and antioxidant enzyme activities were lower. Although foliar application of KNO 3 on JN17 enhanced plant growth, grain yield, and grain quality, these parameters were still lower in T 4 than in T 1 . Our findings suggest that cultivating the salt-resistant wheat cultivar combined with foliar application of KNO 3 at heading stage may alleviate salinity injuries and produce higher grain yield and better grain quality under saline conditions.

Potassium-induced alleviation of salinity stress in Brassica campestris L.

“…K nutrition ameliorated to a great extent the Na + and Cl --accrued decrease in reducing equivalents viz., AsA and GSH which, in turn, had a tight control over the balance between production and scavenging of H 2 O 2 and stabilized the cell membrane by decreasing TBARS content through coordination with other components of the AsA-GSH cycle. Our findings that K nutrition improves the leaf K + and decreases the Na + and Cl -contents confirm those of Qadar and Azam [10], Zheng et al [40,45] and More and Manchanda [39].…”

Effects of External Potassium (K) Supply on Drought Tolerances of Two Contrasting Winter Wheat Cultivars

“…Internal K starvation may decrease some K + -depended enzymes activities and disorder plant physiological metabolism [11]. In addition, K starvation often activates overlapping cell signaling pathways and cellular responses, such as the reductions of chlorophyll production and photosynthetic capacity [12,13]. Electrolyte leakage (EL) and MDA content are two parameters to assess cellular membrane permeability and lipid peroxidation, and the increases of both parameters may indicate drought aggravation [5,10].…”

Positive correlation between potassium uptake and salt tolerance in wheat

“…The positive correlation between P Nmax and g s exists , therefore, the decrease of P Nmax might be caused by the salinity-induced decline of g s . Stomata shrinkage may reduce the intercellular CO 2 concentration (C i ), leading to a shortage of CO 2 available for photosynthesis and resulting in a decrease of photosynthesis (Zheng et al 2010). In addition, the decline of P Nmax might be caused also by nonstomatal limitations.…”

“…Nevertheless, the ST cultivar always maintained higher g s than SS in each treatment. The greater g s is a key factor for better photosynthesis and plant growth under saline conditions (Walker et al 1996, Zheng et al 2010, Redman et al 2011. Stomata opening may be significantly affected by the guard cell water potential (Hattori et al 2007), hence, salinity-induced changes of ion concentrations in guard cells should be further investigated.…”

“…Chl plays a key role and determines a plant photosynthetic capacity under salt stress (Zheng et al 2010). Salinity reduced Chl contents in both cultivars, with the extents being greater in Fig.…”