Enhancing of symbiotic efficiency and salinity tolerance of chickpea by phosphorus supply

This study aims to highlight the beneficial effect of the phosphorus on enhancing of growth plant, the efficiency of use rhizobial symbiosis and ionic partition in chickpea grown under salt stress. Exposure of plants to salt stress (0, 150 mM of NaCl) caused ionic imbalance, which resulted in increased Na+ and P and reduced K+ contents in the leaves and root. Indeed, stressed plants showed decrease of plant growth and phosphorus use efficiency. The efficiency use of rhizobial symbiosis was also affected by salinity. However, addition of two different level of phosphorus (37 and 55 mM) to saline soil increased significantly availability of P in plant organs. Specially, the (150 mM NaCl × 37 mM P) mixture increased (33%) phosphorus use efficiency, induced better nodulation and increased plant biomass which results in the high efficiency in use of the rhizobial symbiosis. Our findings suggest that the combination of low level of P to saline soil presumably improved the tolerance of chickpea plant to salinity. Abbreviations: phosphorus (P); phosphorus use efficiency (PUE); biological nitrogen fixation (BNF); plant dry weight (PDW); yeast extract mannitol (YEM); efficiency in use of the rhizobial symbiosis (EURS); shoot dry weight (SDW); symbiotic nitrogen fixation (SNF)

Interactive effects of salinity and two phosphorus fertilizers on growth and grain yield of Cicer arietinum L.

Chickpea is considered among the most sensitive grain legumes to salinity. The improvement of tolerance of lines in combination with tolerant rhizobial strains depends on various environmental and cultural conditions such as soil properties. This investigation was undertaken to evaluate the effect of phosphorus fertilization (0, 90 and 200 kg ha−1 of P2O5) on biomass, nodular traits and grain yield (GY) of chickpea (cv. Flip 84-79C) growing under salinity (0 and 150 mM NaCl). The trial was laid out following a randomized block design with three replicates during 2010–2012, at the experimental farm of Oued Smar (Algiers). Salinity did not significantly decrease the dry biomass of the plants but the relative shoot growth was more affected than control, P and SP1 treatments. Besides, salinity significantly reduced GY (−20%) and nodulation traits compared to the control plants while an inversely proportional relationship was found between protein, leghemoglobin and MDA content, K/Na ratio and the increase in salt concentration. Application of two P levels to saline soil enhanced growing conditions of plants. Particularly, the (90 kg ha–1 of P × 150 mM NaCl) combination significantly increased leghemoglobin (92%), reduced proline content (−69%) and protected membranes against peroxydation compared to saline conditions. A significant increase was observed in the GY (about 30%) of plants at both P doses combined with salt stress compared to other cases. Statistically, the low P level combined with salinity induced similar responses of plants and sometimes better responses to control plants. Finally, our results support the roles of phosphorus fertilizer in the alleviation of salt stress and enhancing the soil quality for better symbiosis efficiency and yield of chickpea

Act of phosphorus on cell hydraulic state, K+ use efficiency and induction of positive correlations between yield and vegetative traits in chickpea

Salinity is one of the most severe factors that can affect agricultural productivity worldwide particularly in the arid and semi-arid agro-ecological zones. Chickpea seedlings were grown in the field and subjected to different NaCl concentrations (0, 50 and 150 mM) and P application (90 kg ha–1). The experimental design was based on a completely randomised design with three replications. Salinity has disturbed the physiological and ionic state of cells by increasing stomatal resistance and significantly decreased growth and yield parameters (−66%). Under salinity, plant growth traits presented a negative correlation with yield components. P application had positive effect on growth parameters and physiological responses of the plants. Our results suggest that the tolerance of chickpea at (NaCl × P) combination is closely associated with ionic homeostasis and physiological activities of the plants. Phosphorus application allowed salinity tolerance by increasing leaf hydraulic statute, improvement of KUE and consequently enhanced grain yield of chickpea. (P × salinity) combination induced a positive correlation between vegetative traits and yield parameters like unstressed treatment. These results suggest that the use of suitable amounts of phosphorus fertiliser (i. e. 90 kg ha–1) to saline soil is a beneficial starter for plant development, yield components and rehabilitation of degraded soils