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Effect of the addition of Chaetoceros calcitrans,Navicula sp. and Phaeodactylum tricornutum (diatoms) on phytoplankton composition and growth of Litopenaeus vannamei (Boone) postlarvae reared in a biofloc system 
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下载免费PDF全文 Yllana Ferreira Marinho Luis Otavio Brito Clarissa Vilela Figueiredo da Silva Campos William Severi Humber Agrelli Andrade Alfredo Olivera Galvez 《Aquaculture Research》2017,48(8):4155-4164
The aim of this study was to evaluate the effect of the addition of Chaetoceros calcitrans, Navicula sp. and Phaeodactylum tricornutum (diatoms) on phytoplankton composition and the growth of Litopenaeus vannamei postlarvae reared in a biofloc system . Four treatments were used: BFT (biofloc system without feed and no addition of diatoms); BFT‐F (biofloc system with feed and no addition of diatoms); BFT‐D (biofloc system with the addition of diatoms and no feed); and BFT‐FD (biofloc system with the addition of feed and diatoms), all in triplicate. The shrimp (16 ± 0.02 mg) were stocked at 2500 postlarvae m?3 and fed a commercial feed. Diatoms were added on the 1st, 5th, 10th and 15th day at a density of 5 × 104 cells mL?1 for each species. No significant differences (P > 0.05) between treatments were observed for gross primary production, net ecosystem production and water column respiration rate. However, significant differences (P < 0.05) were observed for nitrite, orthophosphate, alkalinity, final weight, weight gain, yield, feed conversion ratio (FCR), phytoplankton and cyanobacteria composition. The BFT‐FD treatment had better performance parameters for final weight (270 mg), weight gain (254 mg), yield (0.67 Kg m?3) and FCR (0.61), indicating the benefits of the diatoms C. calcitrans, Navicula sp. and P. tricornutum for decreasing cyanobacteria and improving growth of L. vannamei postlarvae reared in biofloc systems. 相似文献
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Julie Gombert Frédérik Le Dily Jérémy Lothier Philippe Etienne Laurence Rossato Jean‐Michel Allirand Alexandra Jullien Alexandre Savin Alain Ourry 《植物养料与土壤学杂志》2010,173(6):875-884
In order to optimize nitrogen (N) fertilization and to reduce the environmental impact of oilseed rape without decreasing yield, a clearer understanding of N dynamics inside the plant is crucial. The present investigation therefore aimed to study the effects of different N‐application rates on the dynamics of N uptake, partitioning, and remobilization. The experiment was conducted on winter oilseed rape (Brassica napus L. cv. Capitol) under three levels of N input (0, 100, and 200 kg N ha–1) from stem elongation to maturity using 15N‐labeling technique to distinguish between N uptake and N retranslocation in the plant. Nitrogen fertilization affected the time‐course of N uptake and also the allocation of N taken up from flowering to maturity. Most pod N came from N remobilization, and leaves accounted for the largest source of remobilized N regardless the N‐application rate. However, the contribution of leaves to the remobilized N pool increased with the N dose whereas the one of taproot decreased. Stems were the main sink for remobilized N from stem elongation to flowering. Leaves remained longer on N200 than on N0 and N100 plants, and N concentration in fallen leaves increased with the N treatment and in N100 plants along an axial gradient from the basal to the upper leaves. Overall, these results show that the timing of N supply is more crucial than the N amount to attain a high N efficiency. 相似文献
3.
Is crop N demand more closely related to dry matter accumulation or leaf area expansion during vegetative growth? 总被引：2，自引：0，他引：2
Gilles Lemaire Erik van Oosterom John Sheehy Marie Hélène Jeuffroy Angelo Massignam Laurence Rossato 《Field Crops Research》2007
The critical crop nitrogen uptake is defined as the minimum nitrogen uptake necessary to achieve maximum biomass accumulation (W). Across a range of crops, the critical N uptake is related to W by a power function with a coefficient less than unity that suggests crop N uptake is co-regulated by both soil N supply and biomass accumulation. However, crop N demand is also often linearly related to the expansion of the leaf area index (LAI) during the vegetative growth period. This suggests that crop N demand could be also linked with LAI extension. In this paper, we develop theory to combine these two concepts within a common framework. The aim of this paper is to determine whether generic relationships between N uptake, biomass accumulation, and LAI expansion could be identified that would be robust across both species and environment types. To that end, we used the framework to analyze data on a range of species, including C3 and C4 ones and mono- and di-cotyledonous crops. All crops were grown in either temperate or tropical and subtropical environments without limitations on N supply. The relationship between N uptake and biomass was more robust, across environment types, than the relationship of LAI with biomass. In general, C3 species had a higher N uptake per unit biomass than C4 species, whereas dicotyledonous species tended to have higher LAI per unit biomass than monocotyledonous ones. Species differences in N uptake per unit biomass were partly associated with differences in LAI and N-partitioning. Consequently the critical leaf-N uptake per unit LAI (specific leaf nitrogen, SLN) was relatively constant across species at 1.8–2.0 g m−2, a value that was close to published data on the critical SLN of new leaves at the top of the canopy. Our results indicate that critical N uptake curves as a function of biomass accumulation may provide a robust platform for simulating N uptake of a species. However, if crop simulation models are to capture the genotypic and environmental control of crop N dynamics in a physiologically functional manner, plant growth has to be considered as the sum of a metabolic (e.g. leaves) and a structural (e.g. stems) compartment, each with its own demand for metabolic and structural N. 相似文献
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Effect of the addition of diatoms (Navicula spp.) and rotifers (Brachionus plicatilis) on water quality and growth of the Litopenaeus vannamei postlarvae reared in a biofloc system 下载免费PDF全文
下载免费PDF全文 Luis Otavio Brito Itala Gabriela Sobral dos Santos Jéssika Lima de Abreu Marcele Trajano de Araújo William Severi Alfredo Olivera Gàlvez 《Aquaculture Research》2016,47(12):3990-3997
The aim of this study was to evaluate the effect of the addition of Navicula spp. and Brachionus plicatilis on water quality and growth of postlarvae shrimp Litopenaeus vannamei reared in a biofloc system. Four treatments were considered: a control (biofloc system – BFT); BFT with the addition of Navicula spp. (BFT‐N); BFT with the addition of Brachionus plicatilis (BFT‐B) and BFT with the addition of Navicula spp. and Brachionus plicatilis (BFT‐NB), each in triplicate. Shrimp (16.2 ± 0.03 mg) were stocked at a density of 2500 shrimp m?3 and plankton were added on days 1, 5, 10, 15, 20, 25 and 30 at a density of 5 × 104 cells mL?1 (Navicula spp.) and 30 organisms L?1 (Brachionus plicatilis). The shrimp were fed a formulated feed in four daily rations composed of 40% crude protein and 8% lipids. Significant differences between treatments were observed for final weight, yield, feed conversion ratio, specific growth rate, protein efficiency ratio and protein content of the shrimp. The combined plankton addition of Navicula spp. and B. plicatilis had better performance parameters, indicating their benefit as natural food sources for postlarvae L. vannamei in biofloc systems. 相似文献
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Carlos Alexandre Costa Crusciol Otavio Bagiotto Rossato Rodrigo Foltran Jorge Martinelli Martello 《Communications in Soil Science and Plant Analysis》2017,48(19):2314-2323
The aim of this study was to verify if the application of silicate or lime, in association with gypsum, on sugarcane residue can lead to amendment of subsurface soil acidity, increasing sugarcane yield and profitability. The treatments were: 1 – control (without application of amendments), 2 – gypsum, 3 – dolomitic limestone, 4 – silicate, 5 – dolomitic limestone + gypsum, and 6 – silicate + gypsum. The surface application of gypsum led to reduction in Al (aluminum) contents and Al saturation, and increase in Mg+2, Ca+2, K+, S–SO4?, and base saturation in deeper soil layers, as well as increased yield of stalks, sugar, trash, bagasse, and energy, and greater profit. The application of limestone and silicate, alone or in association with gypsum, amend soil acidity throughout the soil profile. It likewise leads to an increase in stalk, sugar, trash, bagasse, and energy yield, however, application of silicate in association with gypsum leads to the greatest profitability. 相似文献
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Bernardo Melo Montes Nogueira Borges Rilner Alves Flores Hilário Júnior de Almeida Leandro Rossato Moda Renato de Mello Prado 《Journal of plant nutrition》2016,39(11):1627-1633
The correct nutrition of basil (Ocinum basilicum L.) is important to increase its production and quality; however, few papers have deal with this subject. The aim of this work was to evaluate the effects of omission of individual macronutrients on the growth and nutritional status of basil cultivated in nutritive solution. The treatments consisted of nutrient solutions with nitrogen, phosphorus, potassium, calcium, magnesium or sulfur (N, P, K, Ca, Mg, or S) omissions and a complete solution treatment. The plants were cultivated in 8 L plant pots. Plant height, number of leaves per plant, leaf area, relative chlorophyll index, net photosynthesis rate, stomatal conductance, plant dry matter, concentration levels of macronutrients in the aerial part and root system, and nutritional disorders were all evaluated. Nutrient omission was a limiting factor for plant development, substantially reducing its growth. There was also a considerable decrease in nutrient accumulation when compared to the control treatment. 相似文献
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de Souza Kulmann Matheus Severo Arruda Wagner Squizani Vitto Beatriz Baticini de Souza Rodrigo Otavio Schneider Berghetti Álvaro Luís Pasquetti Tarouco Camila Peligrinotti Araujo Maristela Machado Nicoloso Fernando Teixeira Schumacher Mauro Valdir Brunetto Gustavo 《New Forests》2022,53(3):431-448
New Forests - Morpho-physiological characteristics in Eucalyptus species can determine N (NUE) and P (PUE) use efficiency and, consequently, the plant's responses to fertilization. The study... 相似文献
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Francesco Cavraro Giada Finotti Giulia Rossato Matteo Zucchetta Chiara Facca Stefano Malavasi 《水产资源保护:海洋与淡水生态系统》2021,31(6):1311-1321
- In transitional water ecosystems, habitat loss is one of the major threats to fish biodiversity. This is particularly true in the case of temperate salt marshes. Good quality artificial novel habitats may compensate for the loss of natural habitats, acting as a refuge for fish populations.
- The aim of this study was to use coloured ornamental traits exhibited by the males of a small lagoon-resident fish, the Mediterranean killifish Aphanius fasciatus (Valenciennes, 1821), to assess habitat quality in both the natural and artificial creeks of the Venice lagoon.
- The conspicuousness of two secondary sexual traits, the yellow/orange caudal fin pigmentation and the contrast between white and dark vertical bars on body sides, proved to be greater in artificial habitats compared to natural salt marshes, highlighting the refuge function of artificial creeks.
- The use of secondary sexual traits could be extended to other fish species and to other aquatic habitats as a non-invasive approach. This would allow the identification of good quality habitats in the context of fish population management and conservation.