Growth, mineral uptake, chlorophyll content, biochemical constituents and non-enzymatic antioxidant compounds of white pepper (<i>Piper nigrum </i>L.) grown under saline conditions

Abstract

Salinity stress is the main abiotic constraints limiting crop yield worldwide. We investigated the effect of salt stress on growth, dry weight partitioning, chlorophyll content, mineral uptake, biochemical constituents and non-enzymatic antioxidant compounds of white pepper (Piper nigrum L.). White pepper seeds were planted in polythene bags previously filled with sand and supplied with a nutrient solution in a greenhouse during six weeks as a completely randomized design. Plants were subjected to four different concentrations of NaCl (0, 50, 100 and 200 mM). Supplies of intake doses of NaCl in the culture medium significantly decreased the dry biomass, stem height, leaf area and chlorophyll contents respectively from 100 mM NaCl. Mineral elements (K, Ca and Mg) significantly (P < 0.001) decreased in plant organs. The different biochemical constituents (proline, total soluble carbohydrates, soluble proteins and total free amino acids), total phenolic and flavonoids contents significantly (P < 0.001) increased from 50 mM NaCl. The accumulation of biochemical constituents in the leaves increased the osmotic potential of white pepper and could be considered as biochemical indicators of early selection and osmotic adjustment ability for salt tolerant plants. The planting of white pepper in salt affected soils could be encouraged for better development.