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21.
Batista Pedro V. G. Laceby J. Patrick Silva Marx L. N. Tassinari Diego Bispo Diêgo F. A. Curi Nilton Davies Jessica Quinton John N. 《Journal of Soils and Sediments》2019,19(9):3274-3289
Journal of Soils and Sediments - Soils are important regulators of Critical Zone processes that influence the development of geochemical signals used for sediment fingerprinting. In this study,... 相似文献
22.
Elen A. SILVA David C. WEINDORF S&#;rgio H. G. SILVA Bruno T. RIBEIRO Giovana C. POGGERE Teotonio S. CARVALHO Mariana G. M. GON&#; ALVES Luiz R. G. GUILHERME Nilton CURI 《土壤圈》2019,29(4):468-482
Portable X-ray fluorescence (pXRF) spectrometers can be used to determine the elemental composition easily, rapidly, and without using chemical reagents, which is very important for tropical regions due to the lack of detailed soil characterization data. Moreover, pXRF data can be used to predict the results of more expensive, time-consuming, and conventional laboratory analyses. This study sought to determine the elemental composition of various soil profiles using pXRF. Two operational modes (Trace Mode and General Mode) and two scanning time (30 and 60 s) were assessed to determine their effects on the correlation of pXRF dataset with respect to conventional inductively coupled plasma (ICP)-optical emission spectrometry analysis. This relationship has been reported in previous studies, however, few studies were performed on tropical soils, which are unique. Furthermore, such relationships establish the viability of developing prediction models directly from pXRF data. Linear regression was applied to develop calibration models for the prediction of ICP analysis results and exchangeable and available elemental contents based on pXRF data. High coefficients of determination (R2) were obtained for Ca (0.87), Cu (0.90), Fe (0.95), Mn (0.85), Cr (0.95), V (0.72), and Ni (0.90), with adequate validation. Statistically significant results were not found for Al, K, Zn, Ti, and Zr. The models predicting the exchangeable Ca based on the total Ca from pXRF reached an R2 of up to 0.85. Operational modes influenced the pXRF results. Our results illustrate that pXRF holds great promise for tropical soil characterization and the development of prediction models, justifying the need for larger-scale studies in tropical countries worldwide. 相似文献
23.
Eiko E. Kuramae Alexandre L. Buzeto Andreia K. Nakatani Nilton L. Souza 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(4):469-475
In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate Rhizoctonia spp., did not show an anastomosis reaction with any of the binucleate Rhizoctonia spp. testers used. The pathogenicity of the isolates was tested under greenhouse conditions; all isolates were pathogenic
and showed different symptom severities on kale. The ITS-5.8S rDNA sequences of kale isolates and 50 testers (25 binucleate
Rhizoctonia spp. and 25 Rhizoctonia solani) were compared in order to characterize the genetic identity of Rhizoctonia spp. infecting kale. The kale isolates showed genetic identities ranging from 99.3 to 99.8% and were phylogenetically closely
related to CAG 7 (AF354084), with identities of 98.5 and 98.7%. It is suggested that the binucleate Rhizoctonia spp. causing hypocotyl and root rot on kale Brazil comprises a new AG not yet described. 相似文献
24.
Roseli Chela Fenille Nilton Luiz de Souza Eiko Eurya Kuramae 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(8):783-792
Rhizoctonia solani causes pre- and post-emergence damping-off, root and hypocotyl rot and foliar blight in soybean. Foliar blight has resulted in yield losses of 31–60% in north and northeast Brazil. The aim of this study was to characterize isolates of R. solani associated with soybean in Brazil. Among 73 Rhizoctonia isolates examined, six were binucleate and 67 were multinucleate. The multinucleate iso1ates were characterized according to hyphal anastomosis reaction, mycelial growth rate, thiamine requirement, sclerotia production, and RAPD molecular markers. Four isolates that caused hypocotyl rot belonged to AG-4 and using RAPD analysis they grouped together with the HGI subgroup. Another isolate that caused root and hypocotyl rots was thiamine auxotrophic, grew at 35°C, and belonged to AG-2-2 IIIB. All 62 isolates that caused foliar blight belonged to AG-1 IA. RAPD analysis of R. solani AG-1 IA soybean isolates showed high genetic similarity to a tester strain of AG-1 IA, confirming their classification. The teleomorph of R. solani, Thanatephorus cucumeris was produced in vitro by one AG-1 IA isolate from soybean. The AG-4 and AG-2-2 IIIB isolates caused damping-off and root and hypocotyl rots of soybean seedlings cv. FT-Cristalina, under greenhouse conditions. The AG-2-2 IIIB isolate caused large lesions on the cortex tissue, that was distinct from the symptoms caused by AG-4 isolates. The AG-1 IA isolates caused foliar blight in adult soybean plants cv. Xingu under the greenhouse and also in a detached-leaf assay. 相似文献
25.
Offspring Growth in a Diallel Crossbreeding with Three Strains of Nile Tilapia Oreochromis niloticus 总被引：1，自引：0，他引：1
Nilton G. Marengoni Yoshio Onoue Tetsuo Oyama 《Journal of the World Aquaculture Society》1998,29(1):114-119
Abstract— A complete diallel crossing of three strains, Stirling, Korean and Local, was used to evaluate heterosis of intraspecific crossbreeding on early growth of Nile tilapia Oreochromis niloticus . All possible F-1 hybrid offspring were obtained and their growth rates to 90 d were compared. The specific heterosis for F-1 hybrids in Stirling × Korean, Stirling × Local and Korean × Local crosses were 7.61, 5.63 and 7.70 for weight, and 0.47, 0.26 and 0.55 for length, respectively. The purebred Stirling strain showed better growth than the other two strains (P < 0.05). When growth of F-1 hybrids was compared between sexes, males grew more rapidly than females (P < 0.05). However, no differences were observed in growth of male or female between hybrid groups. Purebred males in the Stirling strain were slightly heavier than those in the Korean and Local strains, and Local × Stirling, Korean × Local and Local × Korean crosses. However, in purebred females Stirling was superior to Korean, but not the Local strain and all F-1 hybrid crosses. Implications to choose the appropriate strains for developing a breeding program of tilapia are also discussed. 相似文献
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27.
Yasmmin Tadeu Costa Nilton Curi Geraldo César de Oliveira Luiz Roberto Guimarães Guilherme 《Communications in Soil Science and Plant Analysis》2019,50(6):673-681
Many factors can influence the results obtained by portable X-ray fluorescence analysis (pXRF). The effect of soil organic matter on pXRF results is not satisfactory understood. Thus, we conducted this study to verify the effect of organic matter removal on oxide determination by pXRF in Oxisols. To obtain soil material with different organic matter contents and maintaining the same elemental composition from soil minerals, six contrasting Oxisols were heated in a muffle furnace for 30 min at the following temperatures (°C): 100; 200; 300; 400; 500 and 600. After heating, the soil samples were scanned using a pXRF Bruker® S1 Titan LE model (Dual Soil mode) for 60 s and the contents of SiO2, Al2O3, Fe2O3, TiO2, P2O5, and MnO were recorded. The soil organic matter presence underestimated the pXRF results for lightest oxides (Si and Al) compared to heaviest oxides (Fe, Ti, and Mn). These oxides are important for tropical soils classification and for many soil-related studies and pXRF technology has been a useful tool for soil chemical characterization. Our findings contribute to more suitable use of pXRF highlighting the possible effect of organic matter. 相似文献
28.
Gonçalves Mariana Gabriele Marcolino Avalos Fabio Arnaldo Pomar dos Reis Josimar Vieira Costa Milton Verdade Silva Sérgio Henrique Godinho Poggere Giovana Clarice Curi Nilton de Menezes Michele Duarte 《Precision Agriculture》2022,23(3):1027-1050
Precision Agriculture - This work proposes an approach for establishing coffee management classes mainly supported by pedological information (soil survey) and land parcels, taking into account... 相似文献
29.
dos Santos DR Vitral CL de Paula VS Marchevsky RS Lopes JF Gaspar AM Saddi TM Júnior NC Guimarães Fde R Júnior JG Ximenes LL Souto FJ Pinto MA 《Veterinary journal (London, England : 1997)》2009,182(3):474-480
Active hepatitis E virus (HEV) infections in two Brazilian swine herds were investigated. In study 1, 26 piglets born to five anti-HEV positive sows were monitored from birth to post-partum week 22. Serum samples were screened for the detection of anti-HEV antibodies and a nested RT-PCR used to examine the HEV genome. Passive transfer of immunity was confirmed. At week 22, 23/26 (88.4%) of the piglets had seroconverted. Genome amplification was achieved in a feces pool from one holding pen and in one serum sample, both from 13-week-old animals. Histology was suggestive of a potential HEV infection. In the second study, 47 piglets born to six anti-HEV-positive sows were monitored after weaning. Seroconversion was determined in eight animals at 6-8 weeks of age. HEV RNA was detected in two pools from a holding pen for 12-16-week-old animals. Brazilian isolates were classified as genotype 3. This is the first molecular evidence of HEV infection in Brazilian pig herds. 相似文献