Genotypic differences in response of durum wheat (Triticum durum Desf.) to lime‐induced iron chlorosis

Abstract

Wheat, durum wheat, is the first cereal cultivated and consumed in Tunisia. Because the dominance of calcareous soils in its agroecological systems, known by their low availability of iron (Fe) inducing Fe chlorosis and limiting crop production, its yield remains low. Therefore, the search for tolerant genotypes is always current. In this context, the physiological behavior of six Tunisian genotypes of durum wheat (salim, karim, razek, khiar, inrat100, and maali) cultivated on calcareous and fertile soils for 2 months in a pot experiment was investigated. A greenhouse was used to conduct experiments under natural light. Plant growth, SPAD index, Fe nutrition, Fe distribution, and photosynthesis were monitored and used to evaluate and discriminate their respective physiological responses. On calcareous soil, results revealed reduced plant growth, active Fe, SPAD index, and net photosynthesis. Genotypic differences in the response of wheat to calcareous‐induced Fe deficiency were observed and allowed to classify the genotypes Salim and Karim as relatively tolerant. These genotypes expressed Fe translocation capacity (FeT) up to 3 times, Fe use efficiency for photosynthesis (FeUEAn) up to 1.6 times, and chlorophyll use efficiency for photosynthesis (ChlUEAn) up to 3.5 times greater than that expressed by the other genotypes, particularly inrat100 and maali. Thus, the relative tolerance of Salim and Karim is the result of the high ability of Fe uptake and translocation to shoots to support chlorophyll biosynthesis, photosynthesis, and plant growth as well as an important Fe and chlorophyll use efficiency.

The Physiological Mechanisms Underlying N2-Fixing Common Bean (Phaseolus vulgaris L.) Tolerance to Iron Deficiency

“…Furthermore, chlorophyll biosynthesis and photosynthesis decreased in the two genotypes while maintaining the superiority of CN. In fact, iron is known to be involved in chlorophyll biosynthesis and photosynthesis [11,33,34], as well as the metabolism of some plastidial proteins [26]. Therefore, the observed symptoms of Fe chlorosis and the associated reduction of chlorophyll biosynthesis and net photosynthetic assimilation in this study can be explained by the drastic decrease in iron availability for these key functions.…”

“…Overall researchers have focused on this direct, but expensive, polluting, and unsustainable approach for iron chlorosis correction, leaving aside other efficient approaches [25]. One of these is the exploration of the available plant resources on the basis of their differences in response to iron deficiency in order to highlight tolerant genotypes and identify useful traits of tolerance [26]. In a previous study on four common bean genotypes subjected to iron deficiency, we identified genotypic variability in response to this nutritional constraint based on their rhizosphere acidification and Fe-chelate reductase activity [27].…”

Plant Iron Research in African Countries: Current “Hot Spots”, Approaches, and Potentialities

“…Various synthetic wheat lines were developed in the past by Japanese groups [ 93 ] by crossing the tetraploid wheat cultivar “Langdon” with Aegilops tauschii accessions mainly collected from Iran but also from other Asian countries; three lines with high Fe and Zn content in grains were identified; such traits were stable across the seasons [ 62 ]. Durum wheat genotypes tolerant to growth in calcareous soil were also selected [ 77 ].…”

Morpho-physiological and yield traits of durum wheat (Triticum durum Desf.) response to soil-Fe deficiency

“…Numerous studies have demonstrated that, even if very abundant in the soil, Fe exist mainly in poorly bioavailable inorganic forms that cannot be efficiently absorbed by plants (Darbani et al, 2013;Briat et al, 2015;Tsai and Schmidt, 2017;Venutti et al, 2019). It represents a serious problem for wheat yield in Tunisian soils (Salhi et al, 2022;Zhang et al, 2020). Induced Fe deficiency was demonstrated associated to calcareous, alkaline soils where Fe availability is low (Barhoumi et al, 2021;Krouma et al, 2008;Krouma et al, 2023).…”

“…In plant, Fe plays a key role in redox reactions of numerous metabolic processes such as photosynthesis, respiration and nitrogen assimilation besides being involved in chlorophyll biosynthesis and phytohormones (Marschner, 1995). Photosynthesis, as one of the most important physiological processes on the Earth, is susceptible to iron deficiency (Salhi et al, 2022;Barhoumi et al, 2021;Ouled et al, 2022). Iron is essential for electron flow through the PSII-Cytb6f-PSI complex (Hantzis et al, 2018).…”