RESUMO
BACKGROUND: Zinc (Zn) deficiency is a major human health concern worldwide, and biofortification (genetic and agronomic) is a complementary solution for increasing micronutrient contents, including Zn. Cassava (Manihot esculenta Crantz) has been used for Zn biofortification because it is an important staple crop in most countries affected by malnutrition and Zn deficiency. Thus studies on biofortification of this crop can improve its nutritional quality. Zn content in cassava clones enriched with ß-carotene or lycopene and cultivated under different areas and soil managements was investigated to evaluate the influence of genotypic variation and agronomic management on Zn status in the plant. RESULTS: A clone-specific response to total Zn content in the soil was found, with clones 26, 215, and 240 (ß-carotene enriched) and clones 341 and 395 (lycopene enriched) being the most responsive. For both experiments, there was a positive interaction between total soil Zn and Zn content in the roots. CONCLUSIONS: Our results suggest that, by combining plant breeding and agronomic strategies, it is possible to enrich cassava roots with both zinc and ß-carotene or lycopene. © 2018 Society of Chemical Industry.
Assuntos
Biofortificação/métodos , Licopeno/análise , Manihot/química , Zinco/análise , beta Caroteno/análise , Alimentos Fortificados/análise , Licopeno/metabolismo , Manihot/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Solo/química , Zinco/metabolismo , beta Caroteno/metabolismoRESUMO
Brazil's large land base is important for global food security but its high dependency on inorganic phosphorus (P) fertilizer for crop production (2.2 Tg rising up to 4.6 Tg in 2050) is not a sustainable use of a critical and price-volatile resource. A new strategic analysis of current and future P demand/supply concluded that the nation's secondary P resources which are produced annually (e.g. livestock manures, sugarcane processing residues) could potentially provide up to 20% of crop P demand by 2050 with further investment in P recovery technologies. However, the much larger legacy stores of secondary P in the soil (30 Tg in 2016 worth over $40 billion and rising to 105 Tg by 2050) could provide a more important buffer against future P scarcity or sudden P price fluctuations, and enable a transition to more sustainable P input strategies that could reduce current annual P surpluses by 65%. In the longer-term, farming systems in Brazil should be redesigned to operate profitably but more sustainably under lower soil P fertility thresholds.