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61.
Omidvar Farhadian Leila Daghighi Eisa Ebrahimi Dorche 《Journal of the World Aquaculture Society》2013,44(1):86-95
Population growth and production of the freshwater rotifer, Euchlanis dilatata, were determined after being fed 1 of 12 diets: Scenedesmus quadricauda (S), Chlorella vulgaris (C), baker's yeast (Saccharomyces cerevisiae) (Y), alfalfa meal (Medicago spp.) (A), and eight combinations of S+C, S+Y, C+Y, S+C+Y, S+A, C+A, S+C+A, and Y+A (mixture in the same ratio by equal nitrogen weight). Results showed that both microalgal and alfalfa meal alone and in combination with Y had a significantly higher (P < 0.05) population growth and production compared with Y alone. The mean maximum E. dilatata population density fed on S, S+Y, C, C+Y, S+C, S+C+Y, Y, A, S+A, C+A, S+C+A, and Y+A diets were 65 ± 7.5 (mean ± SE), 124.6 ± 17.2, 115.8 ± 7.9, 41.5 ± 7.9, 131 ± 14.1, 93.5 ± 8.7, 14.5 ± 7.6, 129.5 ± 18.5, 255.0 ± 20.5, 180 ± 30.5, 124.5 ± 25.4, and 61.5 ± 24.5 individuals/mL, respectively. Correspondingly, the mean population growth rates (K) through the 16‐d culture period were 0.29, 0.40, 0.45, 0.27, 0.34, 0.41, 0.26, 0.51, 0.58, 0.59, 0.39, and 0.45/d, respectively. Results indicated that alfalfa meal in combination with microalgae and yeast could be used as primary diets for E. dilatata culture. This may reduce the costs of rotifer production. 相似文献
62.
Regiana dos Santos Moura Taliane Leila Soares Lucas Kennedy Silva Lima Hans Raj Gheyi Onildo Nunes Jesus 《Archives of Agronomy and Soil Science》2020,66(12):1692-1706
ABSTRACT Salinity is one of the most important abiotic stresses limiting agricultural production worldwide. Here, we investigated the biometric, physiological and anatomical changes of Passiflora edulis plants propagated from seeds, cuttings and grafts and exposed to salt stress (0.3 – control and 6.3 dS m?1). Saline stress significantly reduced plant height, the number of leaves, total chlorophyll, stomatal conductance, shoot dry weight, total dry weight, total water consumption and root volume. Among the propagation methods evaluated, plants propagated from seeds were more sensitive to salinity, while plants propagated from cuttings showed smaller alterations when subjected to salinity. Similar behavior was observed for anatomical characteristics, since plants propagated from seeds presented more pronounced anatomical alterations, such as greater thicknesses of the leaf mesophyll, upper epidermis, lower epidermis, palisade parenchyma and spongy parenchyma and also was observed presence of calcium oxalate crystals in the form of druses in greater quantity in the root cortex, in comparison to plants propagated from cuttings. The approach used in this study allowed identifying the type of yellow passion fruit propagation (cuttings) that was best for physiological and anatomical adaptation to salt stress and will be potentially useful in programs for improvement of the crop. 相似文献
63.
Ribeiro Emerson S. Dias Luiz E. Alvarez Víctor Hugo V. Lynch Leila S. 《Journal of Soils and Sediments》2004,4(3):163-169
Background Arsenic (As) availability in natural environment is related to the element’s adsorption and desorption processes in soils.
Total As is better related to available As in temperate soils than in tropical soils. In tropical soils, total As is not very
significant in terms of availability, therefore justifying the necessity for studies into As dynamics. Knowledge of As dynamics
in soil as well as development of new analytical methodologies involving tropical soils are insufficient and necessary for
future mitigation projects.
Objective The objectives of this study were: (1) To adjust methodologies which may assist in understanding arsenate dynamics in tropical
soils and substrates; (2) To evaluate the adsorption and desorption of arsenate in soils and substrate samples, and to find
a minimum value of arsenate available in soil which is lethal to sorghum plants.
Material and Methods Samples of three soils from Minas Gerais State (YL, RYL, and CS) and two sulfide substrates of gold mining (B1 and B2) were
used in the assays. All the material was physically and chemically characterized. Remaining As (As-rem) and remaining P (P-rem)
of each material, along with MACP and MACAs (using the Langmuir isotherms), were obtained. After agitation to obtain MACP and MACAs, arsenate was extracted by anionic resin and Mehlich-III to evaluate arsenate desorption of the material retained on the
filter paper. Subsequently, arsenate desorption curves for the different materials were obtained, and arsenate availability
was determined through a bioassay with sorghum plants. Samples of soils and substrate B1 were incubated with six levels of
As doses. Plants were grown under greenhouse conditions for 30 days. The plants were then harvested, dried and weighed. Available
As in the soils and substrate was determined by Mehlich-III.
Results and Discussions As-rem level decreased from YL (sandy) to RYL (clayey) soil samples, which always showed lower values than P-rem. Among the
soils and substrates evaluated, RYL showed the highest MACAs and MACP, followed by CS, YL and Bl. The results were in accordance with the values observed for As-rem and P-rem and confirm the
idea that the ability of the assayed materials to remove As from the soil/substrate solution is higher than the ability to
remove P. On the other hand, the binding energy (a) between soil/substrate and As is weaker than the binding energy of P.
Given the fact that the studied soils present a real ability to remove As from the solution, only a small part of As would
be unavailable considering MACAs as a reference. As-Mehlich-III values were higher than As-resin for substrate Bl. Mehlich-III seemed to be more appropriate
to extract labile forms of arsenate in substrate B1 as well as in the soils. Available As by Mehlich-III (26.9 mg/dm3) was considered a reference of As LCL to sorghum plants. CC50 was sensitive to the buffering capacity of each soil, showing
values varying from 1.34 mg/dm3 As (clay soil with lower As-rem) to 12.31 mg/dm3 As (sandy soil with higher As-rem).
Conclusions The adaptation of the As-rem and MACAs methodologies was satisfactory and of great value in the study of adsorption, desorption and As availability for soils and
mining substrate. Mehlich-III was also satisfactory to estimate available As and was sensitive to soil buffering capacity.
Nevertheless, resin can also be used as an alternative. MACAs varied among soils and was higher than MACp. However, As showed higher lability than P. Using Mehlich-III, we determined the value corresponding to CC50 that showed
a good reference of toxicity to available As.
Outlook The environmental implications of the As behavior are quite serious. Beside the fact that arsenate is removed very fast from
the soil solution, an anthropogenic input of the element, being part of the soil quantity factor, may remain in a reversible
form for a long time. As may therefore return to the soil solution and becomes available to plants, animals and the entire
environment. Considering that CC50 is the maximum contents of available As the environment can tolerate to allow some vegetal
biomass production, the maximum capacity of As immobilization in each soil is reduced when compared to the soils’ MACAs values. Therefore, the maximum and safe values of reference to be used in the evaluation of incidental discharge of the element
in soils must be reduced. 相似文献
64.
Larissa N. Souza Marcus V. Marin Carolina A. Franco Edgard H. C. Silva Carlos H. Caprio Rita C. Panizzi Leila T. Braz Aleš Lebeda 《Plant pathology》2022,71(2):446-457
During the winter, there is a high occurrence of downy mildew on lettuce caused by Bremia lactucae. This oomycete shows variability in virulence, so understanding the genetic structure of the pathogen population becomes essential for obtaining resistant cultivars. Thus, the objective of this study was to determine sexual compatibility in Brazilian populations of B. lactucae and investigate the occurrence of sexual reproduction of the pathogen on lettuce (Lactuca sativa) and prickly lettuce (Lactuca serriola). Leaf samples were collected in 33 municipalities in seven Brazilian states. The virulence structure of the populations was monitored using the EU-C sextet code. B. lactucae populations from the states of São Paulo, Paraná, Rio de Janeiro, and Rio Grande do Sul shared six of the 15 virulence factors evaluated. Twenty-five virulence phenotypes (v-phenotypes) were found, with the sextet codes 31-00-02, 31-16-02, 31-24-02, and 31-01-02 being more frequent. The predominance of some v- phenotypes indicates that clonal reproduction is still the main form of B. lactucae propagation. The genes and resistance factors of the cultivars Argelès (Dm38), Balesta, and Bartoli are recommended as suitable sources of lettuce resistance in Brazil. Natural occurrence of oospores was detected in most sampled locations, in lettuce and prickly lettuce plants. Virulence variability of Brazilian isolates is the result of the pathogen's ability to reproduce both sexually and asexually, with a prevalence of homothallic isolates; although the majority were of the predominant B2 mating type, there was a high incidence of predominant B1 in addition to B1 = B2. 相似文献
65.
Miranda LH Quintella LP Menezes RC dos Santos IB Oliveira RV Figueiredo FB Lopes-Bezerra LM Schubach TM 《Veterinary journal (London, England : 1997)》2011,(3):408-411
The aim of this study was to apply immunohistochemistry (IHC) for the diagnosis of canine sporotrichosis and to compare this method with the Grocott’s silver stain (GSS) and periodic acid Schiff (PAS) techniques. Eighty-seven dogs with sporotrichosis (group 1) and 35 with American tegumentary leishmaniosis (ATL) (group 2) were studied. The fungus was detected in group 1 by GSS, PAS and IHC. IHC was also applied to group 2 to evaluate the occurrence of cross-reactions. PAS, GSS and IHC detected yeast cells in 19.5%, 43.7% and 65.5% of the group 1 cases, respectively. The detection of intracellular antigens of Sporothrix schenckii by IHC increased the sensitivity of the histological diagnosis to 80.5%. No positive reaction was observed in ATL lesions. The results suggest that IHC may be indicated for the diagnosis of sporotrichosis because of its higher diagnostic sensitivity. 相似文献
66.
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68.
Plant density is the cultivation practice usually employed to manipulate boll distribution, boll setting and yield in cotton production. In order to determine the effect of plant density on the insecticidal protein content of Bacillus thuringiensis(Bt) cotton plants, a study was conducted in Yangzhou University of China in 2015 and 2016. Five plant densities(PD1–PD5, representing 15 000, 30 000, 45 000, 60 000, and 75 000 plants ha–1) were imposed on two Bt cotton cultivars, Sikang 1(the conventional cultivar, SK-1) and Sikang 3(the hybrid cultivar, SK-3). The boll number per plant, boll weight and boll volume all decreased as plant density increased. As plant density increased from 15 000 to 75 000 plants ha~(–1), seed Bt protein content increased, with increases of 66.5% in SK-1 and 53.4% in SK-3 at 40 days after flowering(DAF) in 2015, and 36.8% in SK-1 and 38.6% in SK-3 in 2016. Nitrogen(N) metabolism was investigated to uncover the potential mechanism. The analysis of N metabolism showed enhanced soluble protein content, glutamic-pyruvic transaminase(GPT) and glutamate oxaloacetate transaminase(GOT) activities, but reduced free amino acid content, and protease and peptidase activities with increasing plant density. At 20 DAF, the seed Bt toxin amount was positively correlated with soluble protein level, with correlation coefficients of 0.825** in SK-1 and 0.926** in SK-3 in 2015, and 0.955** in SK-1 and 0.965** in SK-3 in 2016. In contrast, the seed Bt protein level was negatively correlated with free amino acid content, with correlation coefficients of –0.983** in SK-1 and –0.974** in SK-3 in 2015, and –0.996** in SK-1 and –0.986** in SK-3 in 2016. To further confirm the relationship of Bt protein content and N metabolism, the Bt protein content was found to be positively correlated with the activities of GPT and GOT, but negatively correlated with the activities of protease and peptidase. In conclusion, our present study indicated that high plant density elevated the amount of seed Bt protein, and this increase was associated with decreased boll number per plant, boll weight and boll volume. In addition, altered N metabolism also contributed to the increased Bt protein content under high plant density. 相似文献
69.
Shabahang L 《Pakistan journal of biological sciences: PJBS》2010,13(22):1106-1109
Erythema Multiforme (EM) is a type of allergic reaction that occurs in response to medications, infections, or different illnesses. In many cases, a definite underlying cause may not be identified. This study aimed to evaluate adult EM outpatients with regard to patients' characteristics, the disease and the underlying contributors. In this cross-sectional study, 61 adult EA outpatients referred to the Dermatology Clinic of Tabriz Sina Hospital were recruited during a 12-month period (January 2009-January 2010). The diagnosis was made based on clinical and morphologic grounds. Age, sex, types of EA, location and type of the lesions and the underlying causes were documents. An infectious etiology was suspected when a preceding illness was noticed without drug ingestion within 1 week prior to the onset of the rash. A drug related to the condition was defined as every drug that has been taken during 21 days prior to the onset of any symptoms. There were 34 males and 27 females with a mean age of 26.8 +/- 15.3 (18-57) years enrolled. The EM was minor in 62.3% and major in 37.7% of patients. The upper limb was involved in all patients. The lesions were maculo-papular, vesiculobullous and bullous in 83.6, 13.1 and 3.3% cases, respectively. Drugs and herpes simplex were the main causes in 49.2 and 16.4% of patients, respectively. The disease was idiopathic in 34.4%. The underlying drugs were sulfonamides in 12 cases (19.7%), penicillin in 5 cases (8.2%), salicylic acid, aspirin, cimetidine and amoxicillin each one in 3 cases (4.9%) and barbiturate in 1 case (1.6%). Five cases (8.2%) were recurrent EM including 4 males and 1 female, 3 idiopathic and 2 cases due to sulfonamides. 相似文献
70.
Seyed Hassan Eftekhar-Vaghefi Leila Zahmatkesh Parvin Salehinejad Shahin Totonchi Ali Shams-Ara 《Iranian Biomedical Journal》2015,19(2):82-90