Effect of sodium chloride on physiological, biochemical traits, and mineral nutrition inhibition of peanut varieties in large temperature fluctuations

•This experimental study focuses on the seeds of groundnut varieties ICGV 86003, Metchicha and JL 24 collected from the IRAD of Maroua and cultivated in a saline medium in large temperature fluctuation.•The results reveal that, these varieties developed adaptative physiological and biochemical mechanisms under the NaCl / large temperature fluctuation couple. They also reveal that, the uptaking mineral elements by these varieties under the NaCl / large temperature fluctuation couple are inhibited in that condition compared to those grown at the same temperature in a medium devoid of NaCl.•Their behavior towards NaCl makes them salt-tolerant varieties and the inhibition of mineral absorption by these plants predicts the poor organoleptic quality of the fruits. Peanut has a high nutritional value which would be influenced by soil salinization that arises because of climate change. In this paper, the effects of salinity on morphological, physiological biochemical parameters and mineral absorption inhibition of the three varieties cultivated in Cameroon, namely ICGV86003 (V1), Metchicha (V2), and JL 24 (V3) were evaluated under large temperature fluctuations. Plants of each variety were grown at four concentrations of Wacquant's nutrient solution 0, 40, 80, and 120 mM of NaCl 20 days after germination under an unstable environment. The experiment pots were arranged in a completely randomized design with five replicates. The results showed that the three studied peanut varieties present distinct indicators for salt tolerance. Total Leaf Area (TLA), Fresh Weight (FW), and Relative Water Content (RWC) decreased from 80 mM, 40mM, and 80 mM of NaCl respectively. Bound water (BW) increased from 40 mM of NaCl in all varieties. Total sugars, total protein, and peroxidase content increased from 40 mM of NaCl, while polyphenol content increased from 40 mM NaCl in the V1 variety and 80 mM of NaCl in the V2 and V3 varieties. In addition, nutrient elements left in the soil were elevated from 40 mM of NaCl while N was reduced under the same salt conditions for V2, V3, and V1 respectively. These results suggest that the adaptive mechanism of the studied varieties of peanut to salt stress under temperature fluctuations reduces the uptake of mineral elements by the plant and is at the origin of the poor organoleptic quality of fruits.