Photosynthetic responses of durum wheat to chemical/microbiological fertilization management under salt and drought stresses

Mohammad Yaghoubi Khanghahi,Carmine Crecchio,Beniamino Leoni

doi:10.1007/s11738-021-03289-z

Mohammad Yaghoubi Khanghahi, Carmine Crecchio + Show 1 more

Open Access

https://doi.org/10.1007/s11738-021-03289-z

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Abstract

The current research was carried out to evaluate the stress tolerance potential of durum wheat plants, in response to the inoculation of native plant growth-promoting bacteria (PGPB), through assessing PSII photochemistry and photosynthetic traits, as well as grain yield and plant height, and to investigate the possibility of using PGPB as a sustainable alternative or in combination with traditional fertilization plans. A greenhouse experiment included chemical/microbiological fertilization and stress (salinity and drought) treatments. The results indicated that the application of bacterial consortium of four PGPB markedly augmented some biochemical and functional traits in photosystem II, such as effective quantum yield of PSII photochemistry (Y(II)), electron transport rate of PSII (ETR), photosynthesis capacity, transpiration rate and stomatal conductance in unstressed plants, and prevented severe changes in the mentioned traits under drought and salinity conditions. The application of PGPB contributed to enhanced grain yield, too. Furthermore, a better performance of the PGPB inoculation was found in combination with half-dose of the recommended chemical fertilizers. In conclusion, PGPB inoculants maintain or improve the photosynthesis efficiency of durum wheat, grain yield and plant height, particularly under stress conditions, and can help to minimize the consumption of chemical fertilizers.

Highlights

Durum wheat (Triticum durum Desf.) is one of the most widely grown cereals all over the Mediterranean region, where crops are continuously subjected to environmental stresses, salinity and drought (Guidi and Calatayud 2014; Chairi et al 2019), as the main environmental factors constrain crops productivity by affecting physiological processes (Nowicka et al 2018)
When plant growth-promoting bacteria (PGPB) were combined to half-dose of chemical fertilizer (I + 1⁄2CF), these increments were 30.4, 10.8, 40.5, 9.6 and 25.5%, respectively (Table S1)
The highest amounts of chlorophyll and SPAD values were obtained from combined treatment of bacterial inoculants and a full dosage of chemicals (I + CF treatment) under non-stress condition, equal to 561.3 μmol m−2 and 53.5, which were 45 and 21% higher than those in unfertilized plants, 31 and 14% more than PGPB-inoculated plants, and 24 and 10% higher that plants treated by chemical fertilizers (Table S1)

Summary

Introduction

Durum wheat (Triticum durum Desf.) is one of the most widely grown cereals all over the Mediterranean region, where crops are continuously subjected to environmental stresses, salinity and drought (Guidi and Calatayud 2014; Chairi et al 2019), as the main environmental factors constrain crops productivity by affecting physiological processes (Nowicka et al 2018). Very large amounts of mineral fertilization inputs are generally used to provide crop plants with the essential nutrients, because of low availability of some nutrients in soil (e.g. N and P) for crop uptake (Bakhshandeh et al 2015; Balasubramanian et al 2015) and of low solubility of some of them (e.g. Zn) in soil that can be too slow to meet crop nutrient requirements (Rengel 2015) This issue is associated with the prices and availability of fertilizer inputs as the most important challenge facing today’s farmers (Meena et al 2017), especially in Italy, one of the Mediterranean countries and the secondworld producer of durum wheat with 4 million tons of grain in 2018 (ISTAT 2018)

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