Micronutrient-efficient genotypes for crop yield and nutritional quality in sustainable agriculture. A review

Abstract

About 4 billion people will be added onto the present population by 2050. To meet further demand for food, agricultural production should increase on the existing land. Since the Green Revolution, higher crop production per unit area has resulted in greater depletion of soil phytoavailable micronutrients while less attention has been paid to micronutrients fertilization. Now, micronutrient deficiency has become a limiting factor for crop productivity in many agricultural lands worldwide. Furthermore, many food systems in developing countries can not provide sufficient micronutrient content to meet the demands of their citizens, especially low-income families. There are several solutions such as soil and foliar fertilization, crop systems, application of organic amendments to correct micronutrients deficiency and to increase their density in edible parts of plants. This review article presents (1) agronomic approaches to improve crop yield and micronutrient content of food crops, and (2) genotypic variation in uptake and accumulation of micronutrients. Considering ecological concerns, cultivation and breeding of micronutrient-efficient genotypes in combination with proper agronomic management practices appear as the most sustainable and costeffective solution for alleviating food-chain micronutrient deficiency. Micronutrient-efficient genotypes could provide a number of benefits such as reductions in the use of fertilizers, improvements in seedling vigor, and resistance to abiotic and abiotic stresses. Using bioavailable micronutrient-dense staple crop cultivars can also be used to improve the micronutrient nutritional status of human. micronutrients / nutrient efficiency / biofortification / stress-tolerance indicators

Nutritionally Enhanced Staple Food Crops

“…In terms of agronomic efficiency, it can simply be defined as yield per unit of nutrient (Fe and Zn in this case). Relative to internal requirement or the physiological efficiency for a nutrient, it can be defined as the yield (economic or total) per unit uptake of the nutrient (for detailed discussion, see Gourley et al 1994;Marschner 1995;Baligar et al 2001;Rengel 2001;Fageria et al 2008;Khoshgoftarmanesh et al 2010). For the purpose of this section for selecting nutrient (Fe and Zn) rich seeds, we interpret the Fe and Zn efficiencies of a crop or genotype in terms of seed concentrations of these nutrients.…”

“…These genotypic differences can arise from greater uptake or greater allocation of the micronutrients to the seed where they allow for better seedling establishment (Baligar et al 2001;Fageria et al 2008;Khoshgoftarmanesh et al 2010). In calcareous soils, rye, triticale, bread, and durum wheat showed differential response to Zn efficiency, rye being exceptional in its high Zn efficiency, followed by triticale > bread wheat > durum wheat, which could be attributed to its greater Zn uptake capacity from soils (Cakmak et al 1997b;Erenoglu et al 1999).…”

“…Additionally, greater stress tolerance has been noticed in seedlings grown from micronutrient-dense seeds resulting in higher agricultural production (Welch 1986;Cakmak 2008). Agronomic biofortification is not the subject of this review but includes cropping systems diversification, fertilizer enrichment, seed priming, or use of soil microorganisms such as mycorrhizal fungi to improve soil rhizosphere environments for better acquisition of immobile mineral elements from the root zones (He and Nara 2007;Cakmak 2008;Cavagnaro 2008;Khoshgoftarmanesh et al 2010).…”

Zinc fractions in soil and uptake by wheat as affected by different preceding crops

“…On the other hand, the preceding crop management affects soil physical, chemical and fertility properties and in turn modifies the availability of metal nutrients in soil (Khoshgoftarmanesh et al 2010). Soltani et al (2014) investigated the effect of different preceding crops residues on the total amino acids and dissolved organic carbon (DOC) concentration in rhizosphere soil solution and grain Zn content of two different Zn deficiency-tolerant wheat cultivars.…”

Transplastomic plants for innovations in agriculture. A review

“…Exploitation, improper land use, and heavy chemical inputs, e.g., from pesticides and fertilizers, by the modern, intensive agriculture in order to achieve high crop yields in monocultures (Zuo and Zhang 2009) often result in pollution and nutrient imbalance in the soil. These perturbances lead to the accumulation of harmful compounds or nutrient deficiency, respectively, in edible plant parts (Khoshgoftarmanesh et al 2010;Solymosi and Bertrand 2012). However, farmers and companies do not necessarily take into account the long-term consequences of their land use and strive, instead, to maximize their profit on a short term.…”