Kirkuk University Journal for Agricultural Sciences (KUJAS)

Synergistic and Antagonistic Effects of pH Interactions with Sodium Chloride on The In Vitro Growth of (Medicago Sativa L.)

https://doi.org/10.58928/ku26.17205
Volume 17, Issue 2
Spring 2026
Page 39-46
Kirkuk University Journal for Agricultural Sciences (KUJAS)

Document Type : Research Paper

Authors

Jilan H. Hussein 1
Fareed Khalid Yaseen 2
Atheel N. Yousef 1
Gharbia H. Danial 3

1 Department of Biology, College of Science, University of Duhok. Kurdistan Region, IRAQ

2 Department of Environmental Science /College of Science / University of Zakho

3 Scientific Research Center, College of Science, Duhok University, Kurdistan Region, IRAQ

Abstract
Salinity and medium pH are critical abiotic factors influencing plant growth, yet their interactive effects remain poorly understood. This study aimed to evaluate the primary and interacting effects of medium pH and sodium chloride (NaCl) on the in vitro development of Medicago sativa L. (cv. CUF 101). A 3 × 4 factorial design was employed to investigate pH levels of 4.5, 6.5, and 8.5 in conjunction with NaCl concentrations of 0, 60, 120, and 180 mM in a completely randomized design, with growth traits (root and shoot length, biomass, and leaf number) measured after 21 days of germination. This approach allowed us to capture responses across varying gradients of saline-pH stress. The effects of pH, salinity, and their interaction were all found to be highly significant (p < 0.01). Near-neutral pH (6.5) consistently maximized biomass and exhibited antagonistic effects by alleviating the growth inhibition caused by NaCl. Conversely, acidic conditions (pH 4.5) combined with NaCl produced synergistic effects, resulting in disproportionate shoot elongation without an accompanying increase in their biomass. Under alkaline conditions (pH 8.5) with NaCl, the interaction also acted synergistically, severely inhibiting root elongation and indicating an early failure of root establishment. Salinity imposed a range of penalties on all traits, exhibiting significant reductions beyond approximately 120 mM and approaching a critical collapse at 180 mM. The correlations among traits indicated a trade-off in stress allocation: root length was positively correlated with total biomass and negatively correlated with shoot elongation and leaf number. These findings demonstrate that precise pH management is essential for optimizing salt tolerance in alfalfa with implications for cultivar screening under saline-alkaline stress.

Keywords

Keywords: Medicago sativa
salinity (NaCl)
pH (acidic&ndash
alkaline)
in vitro culture
salinity&ndash
pH interaction
Subjects
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