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Genetic improvement in aluminium tolerance is one of the most cost-effective solutions to improve the productivity of wheat ( Triticum aestivum L.) in acid soils. Sources of tolerance to this abiotic stress within adapted germplasm are limited, so the identification and characterisation of new sources are of some priority for the future of plant breeding in target areas. The aim of this study was to evaluate the response to aluminium stress of an old Portuguese wheat collection and to select the most tolerant ones for genetic and breeding purposes. An old collection of Portuguese wheat cultivars and some ‘Barbela’ lines were tested and classified in relation to aluminium tolerance and compared to modern wheat cultivars using a hydroponic approach. Three bread wheat cultivars (‘Viloso Mole’, Magueija’ and ‘Ruivo’) showed greater tolerance to 5 ppm aluminium than the international wheat standard cultivar ‘BH1146’, and so represent excellent material for understanding the genetic control of aluminium tolerance. In addition, several accessions of the Portuguese landrace ‘Barbela’ were outstanding in terms of aluminium tolerance. In particular, line 7/72/92 had a pronounced advantage over ‘BH1146’ in terms of root regrowth.

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Abstract  

Some35S labeled thiophene derivatives have been prepared by biosynthesis inin vitro cultures ofTagetes sp. A different sources of isotopic sulfur were tested and the best results were achieved with [35S] sodium sulfate. Elemental sulfur was not incorporated. Radiochemical yields were around 1%.

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Abstract  

Selenium is an essential micronutrient for humans and animals, yet it is deficient in at least one billion people worldwide. Plants and plant-derived products transfer the soil-uptaken selenium to humans; therefore, the cultivation of plants enriched in selenium can be an effective way to improve the selenium status on humankind. This paper focuses on determining the ability of bread wheat to accumulate selenium after supplementation. One of the methods for supplementing this element in plants is foliar application with selenium solutions. These supplemented crop of wheat samples—bread wheat; Triticum aestivum L.—were used to determine if there is an increase of selenium content in cereal grains by comparing them with cereals cultivated in 2009 and harvested in 2010 with no supplementation. The experiments were done using sodium selenate and sodium selenite at three different selenium concentrations: 4, 20 and 100 g per hectare. Total Se is assessed by cyclic neutron activation analysis (CNAA), through short irradiations on the fast pneumatic system (SIPRA) of the Portuguese Research Reactor (RPI-ITN). The short-lived nuclide 77mSe, that features a half-lifetime of 17.5 s, was used to determine the Se content in SIPRA. The experiment was successful, since the selenium concentration increased in the cropped grains and reached values up to 35 times the non-supplemented ones.

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Abstract  

Selenium (Se) is an essential micronutrient for human health, but its deficiency may affect at least one billion people worldwide. Plants and plant-derived products transfer the soil-uptaken Se to humans through the food chain, which is hardly enough when soils have been always poor or already exhausted in bioavailable Se species. Other than agronomic approaches for enhancing Se levels in cereals, such as soil and foliar supplements, seed enrichment may be viewed as an alternative Se-biofortification technique. This study addresses the protocol for preparing Se-enriched wheat seeds, with the specific purpose of optimizing the administration of Se to the seeds prior to sowing. The first step was to soak an amount of bread-wheat seeds in an active Se solution, made with irradiated [Na2O4Se], and then monitoring 75Se in periodically-retrieved samples from that original amount. To avoid losing Se to soil (after sowing), and, especially, to ensure that Se gets really absorbed into the seeds—and not just adsorbed onto them—the washing time of the seeds should be optimized as well. This was carried out by washing Se-treated seeds several times, until no significant amount of the radiotracer could be detected in the washing water. In what concerns the full optimization procedure, the overall results of the present study point to an optimum time of 48 h for soaking and 24 h for washing.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: C. Galinha, M. Freitas, A. Pacheco, J. Kameník, J. Kučera, H. Anawar, J. Coutinho, B. Maçãs, and A. Almeida

Abstract  

Selenium (Se) is an essential micronutrient for human health but it is deficient in at least 1 billion people around the globe. Cereals are by far the most significant agricultural crops, not only on a gross tonnage basis, but also by what they represent in terms of energy supply and dietary intake for human nutrition worldwide. Portugal is no exception to such pattern. The Portuguese situation is difficult to assess though, due to scarce information and lack of consistent studies on the subject. In these terms, the Se status of major cereals and their cultivation soils are dealt with herein. Two species of wheat–bread and durum wheat–were sown at the end of November 2009, and then sampled in different growth stages. Rye was collected during harvest season, and cultivation soils were analyzed as well. Se results were within the range of: 100–225 ng g−1 for soils; 3–55 ng g−1 for durum wheat; 6–80 ng g−1 for bread wheat; and 4–30 ng g−1 for rye. Accuracy of the RNAA procedure was proved by analysis of reference materials NIST-SRM 1515 and NIST-SRM 8433.

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