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51.
Hugo Alves Pinheiro Jos Vieira Silva Laurício Endres Vilma Marques Ferreira Celene de Albuquerque Cmara Fbio Flix Cabral Jaqueline Figueredo Oliveira Lúcio Wagner Torres de Carvalho Joo Messias dos Santos Benedito Gomes dos Santos Filho 《Industrial Crops and Products》2008,27(3):385-392
Brazilian castor bean (Ricinus communis L) crops have expanded towards semiarid lands, in which soil salinity is an important factor limiting plant development. In order to evaluate the effects of salt stress on leaf gas exchange, pigments, and dry matter accumulation of seedlings, seeds of castor bean var. BRS Nordestina were planted in 15-L pots filled with 13 kg of soil (control) or with soil plus 2 g NaCl kg−1 soil corresponding to 30 mM NaCl (salt treatment). Seedlings were grown under greenhouse conditions and the effects of salinity were assessed by measuring physiological parameters at 38 and 59 days after germination. Salt treatment induced decreases in leaf water potential at pre-dawn (ψpd, 42%), stomatal conductance to water vapor (gs, 36%), and net carbon assimilation rate (A, 24%) only at 38 days after germination. At the same time, the values for transpiration rate were unchanged and the hydraulic conductance was increased (34%). After 59 days under hypersalinity, leaf ψpd increased to −0.44 MPa, although gs, A, transpiration rate, and hydraulic conductance were not different between treatments. Salt stress effects on chlorophyll a, chlorophyll b and chlorophyll a + b contents were evident only on experimental day 59. The dry matter accumulation of leaves, roots and stems, as well as the total dry matter, and the root to above ground ratio increased with plant growth in both treatments, however, these parameters were lowered in salt-stressed seedlings. In short, all physiological variables were more drastically affected after 38 days under high salinity, and despite acclimatization of A after 59 days exposure to salt, no recovery of the dry matter accumulation was observed in the seedlings, suggesting that this species does not tolerate salt stress at its initial growth stages. 相似文献
52.
Teresa M. M. dos Santos Humberto Nóbrega José Filipe Teixeira Ganan?a Emanuel Silva Desire Afonso Abílio F. M. Gutiérres Jan J. Slaski Manhaz Khadem Miguel ?. A. Pinheiro de Carvalho 《Genetic Resources and Crop Evolution》2012,59(7):1377-1388
The genetic variability of high molecular weight glutenin subunits (HMWGS) composition at the Glu-1 loci in bread wheat (Triticum aestivum L.) was studied electrophoretically using the SDS–PAGE in 3,470 individuals representing 159 populations originated from the Canary Islands (Spain), the Archipelago of Madeira (Portugal) and the continental Portugal. A total of 25 alleles were detected, resulting in 69 different allele combinations. The geographical distribution of the high molecular weight glutenin alleles confirms historical data regarding circulation of wheat germplasm between the Iberian Peninsula and Madeira and between Madeira and the Canary Islands and vice versa. 相似文献
53.
Eduardo Gusmão Pereira Marco Antonio Oliva Advânio Inacio Siqueira-Silva Laíse Rosado-Souza Daniel Teixeira Pinheiro Andréa Miyasaka Almeida 《Journal of plant nutrition》2014,37(9):1373-1394
In iron toxic wetlands, ferric hydroxide is commonly deposited on rice roots. This study aims to to evaluate the differences in iron plaque formation in rice cultivars from different cropping systems. Thirty days old seedlings of Brazilian rice cultivars from the lowland cropping system (‘BRS Atalanta’ and ‘Epagri 107’) and upland cropping system (‘Canastra’) or both systems (‘BRSMG Curinga’) and the cultivar ‘Nipponbare’ were exposed to iron excess [4 mM iron sulfate heptahydrate (FeSO4.7H2O)] for seven days in nutrient solution. It was observed iron plaque formation and ruptures of the root epidermal cells. The lowland cultivars showed higher Fe content in iron plaque. Iron stain was detected in the root hairs, epidermis, hypodermis, and exodermis. The root exodermis may be contributed to prevent the deposit of iron in the cortex of the lowland cultivars and in the cultivar ‘BRSMG Curinga’. It was observed in plants with iron plaque formation significant reductions in the shoot content of phosphorous, manganese and magnesium due to different causes. The differences in iron plaque formation among the cultivars might be an indicative of variations in exodermis selectivity, root oxidative capacity, and iron nutrition mechanisms. 相似文献
54.
MJG Bezerra JALO Cruz ES Kung PPF Albuquerque PCP Kim EPBX Moraes JW Pinheiro Júnior RA Mota 《Reproduction in domestic animals》2014,49(5):753-755
The aim of this study was to estimate the prevalence of genomic DNA of Toxoplasma gondii in semen samples from commercial rams in artificial insemination centres in Brazil, as well as in fresh semen from rams in the northeast of Brazil. In total, 108 semen samples were obtained from artificial insemination centres, and genomic DNA of T. gondii was detected in 24 of 108 (22.2%). The prevalence of antibodies anti‐Toxoplasma gondii among sheep on rural properties was 9.2% (10/109), and 100% of the semen samples of these animals were positive in the PCR for T. gondii DNA. The molecular identity was confirmed through sequencing, which indicated 99.9% similarity with the T. gondii DNA sequences stored in the GenBank. This study reports the first occurrence of T. gondii DNA in the semen of rams, which came from artificial insemination centres in Brazil, as well as the occurrence of T. gondii DNA in the fresh semen of naturally infected rams in the northeast of Brazil. 相似文献
55.
Compatibility of the fungus Metarhizium anisopliae and deltamethrin to control a resistant strain of Boophilus microplus tick 总被引:1,自引:0,他引:1
The tick Boophilus microplus causes economic impact to cattle producers and has a great capacity to develop resistance to chemical acaricides. It is very important the development of new techniques to complement the control of this parasitosis. Biological control is a promising option to maintain acceptable levels of tick populations in cattle. Therefore, the present study evaluated the association of deltamethrin and the entomopathogenic fungus Metarhizium anisopliae against B. microplus larvae resistant to pyrethroid. The synthetic pyrethroid, deltamethrin, was used at concentrations of 0.39, 0.78, 1.56, 3.12 and 6.12 ppm, M. anisopliae was used at concentrations of 10(5), 10(6), 10(7) and 10(8) conidia ml(-1). Their associations were also evaluated in in vitro tests. The assays showed that the tick strain is resistant to deltamethrin, but high mortality rates were observed when deltamethrin was associated with the entomopathogen. The larvae's mortality rates ranged from 7 to 36.5% for the different concentrations of deltamethrin, however, for the different concentrations of M. anisopliae, the mortality rates ranged from 10 to 96.9%. Mortality rates were proportional to the concentrations used for both deltamethrin and the fungus. Predominantly, the association of pyrethroid and fungus resulted in higher larvae mortalility rates than those obtained with the respective non-associated concentrations. Thus, the present study indicates that this association can be used as a tool for integrated control of the tick B. microplus. 相似文献
56.
1. The use of in vivo real-time ultrasonic (RTU) to predict breast and carcase weights and yields in 103 male broiler chickens was evaluated. Breast area (mm(2)), thickness (mm) and volume (cm(3)) were measured by RTU in three identified sites. After RTU measurements, the broiler chickens were weighed (live weight, LW, g) and slaughtered Carcase and breast weights (g) and physical measures of breast area (mm(2)), and thickness (mm) corresponding to the three identified sites, and volume (cm(3)) were recorded. 2. The best simple correlation between RTU and carcase measurements was obtained for breast volume. Breast and carcase weights were well predicted by LW. Furthermore, breast volume measured in carcase or by RTU was better in predicting breast weight and breast and carcase yields. 3. Multiple regression equations were fitted using LW (g) and RTU measurement of breast volume to predict breast and carcase weights and yields. The coefficients of determination were 0.52 and 0.65 for breast and carcase yields, respectively, and 0.92 and 0.99 for breast and carcase weights, respectively. 相似文献
57.
Jos M. Santos Maria T. Ferreira Antnio N. Pinheiro Jorge H. Bochechas 《水产资源保护:海洋与淡水生态系统》2006,16(4):373-388
- 1. Over the last decade the development of small hydropower projects has been one of the most active areas of the energy sector. One of the main environmental challenges faced by such projects is related to fish passage.
- 2. The impact of 18 small hydropower plants (SHPs) with distinct levels of fish‐pass effectiveness was investigated in the summers of 1998 and 1999 by comparing fish assemblage composition and structure at 36 sites, above and below SHPs.
- 3. With regard to effectiveness, it was estimated that eight (44.4%) of the surveyed passage facilities were suitable for target species, whereas the remaining 10 (55.6%) were considered unsuitable. In neither case did the composition of fish assemblages upstream and downstream from SHPs differ significantly, while assemblage similarity was relatively high.
- 4. Multivariate techniques identified cover, depth and coarse substrate as the main parameters structuring fish assemblages. It is suggested that these variables have created a rich, patchy, heterogeneous habitat, thereby providing satisfactory resources and favourable conditions required by fish and contributing to the maintenance of assemblages.
- 5. Although populations of some species that occurred both upstream and downstream from SHPs have developed differences in their size structures, SHP‐induced fragmentation of fish populations may not necessarily result in genetic divergence among semi‐isolated populations.
58.
Rocha Ribeiro SM Queiroz JH Lopes Ribeiro de Queiroz ME Campos FM Pinheiro Sant'ana HM 《Plant foods for human nutrition (Dordrecht, Netherlands)》2007,62(1):13-17
This work was carried out to investigate the pulp composition of four mango cultivars (Haden, Tommy Atkins and Ubá) at the
ripening stage in relation to three components with antioxidant potential (total phenolics, carotenoids and ascorbic acid).
Total phenolic compound content was estimated by the Folin-Ciocalteu reagent and total carotenoid content by spectrophotometry
at 450 nm. The contents of β-carotene and total vitamin C (ascorbic acid and dehydroascorbic acid) were quantified by high performance liquid chromatography.
Differences were found among the four mango cultivars in all the components analyzed. The content of phenolic compounds ranged
from 48.40 (Haden) to 208.70 mg/100 g (Ubá); total carotenoid from 1.91 (Haden) to 2.63 mg/100 g (Palmer); β-carotene from 661.27 (Palmer) to 2,220 μg/100 g (Ubá) and total ascorbic acid ranged from 9.79 (Tommy Atkins) to 77.71 mg/100 g
(Ubá). These results corroborated previous information that mangoes are a good source of antioxidants in human diet. 相似文献
59.
60.
Miguel . A. Pinheiro de Carvalho Jan J. Slaski Ivo Abreu Filipe T. Ganana Teresa M. M. dos Santos Lurdes Freitas Maria R. Clemente Vieira Antonieta Nunes Ana Domingues Gregory J. Taylor 《植物养料与土壤学杂志》2004,167(1):93-98
Forty genotypes representing maize genetic diversity from the Island of Madeira were screened for resistance to aluminum (Al) in nutrient solution. Seeds of maize were obtained from local farmers from field plots spread around the island in a range of altitudes from 99 to 1000 m above sea level. The content of ionic aluminum and the pH of soils cultivated with maize were determined. The mean pH value of all examined soils was 4.9, while the mean ionic Al content was 0.76 cmol kg–1. Seventy‐two hours (h) exposure to 100 and 200 μM Al followed by a 48 h recovery period of 4‐day old seedlings revealed significant differences in Al resistance in the Madeiran maize germplasm. Root survival and regrowth exceeding 80 % of the seedlings were observed in 22 and 8 of the tested genotypes screened at 100 and 200 μM Al in nutrient solution. High Al resistance among Madeiran maize genotypes appeared not to be associated with the lower pH of soil, and did not correlate with the amount of soil Al3+ or the altitude at the site of collection. The high level of Al resistance of the maize cultivars indicates an initial genetic trait enhanced by open pollination of maize. 相似文献