TOPSIS在农作物品种评价中的应用研究

针对农作物品种评价的多性状特性,提出将TOPSIS方法用于农作物品种评价。实例结果表明,该方法简单易行、准确有效,适合具体应用。     

Response of Passiflora setacea to Mycorrhization and Phosphate Fertilization in a Semiarid Region of Brazil

The Caatinga is a unique biome that encompasses nearly 11% of Brazil's territory and contains diverse vegetation composed of trees and bushes that have been scarcely studied from the economic perspective. In this context, Passiflora setacea may constitute a strategic alternative for agriculture because it produces fruit that has commercial potential and is tolerant to some diseases. Some species of Passiflora show more robust growth when associated with arbuscular mycorrhizal fungi (AMF) and are dependent on mycorrhization. In this study, the response of P. setacea to phosphate (P) fertilization and mycorrhization with Claroideoglomus etunicatum was evaluated. The experimental design included eight replicates of four randomized treatments: non-inoculated plants (NI), plants fertilized with phosphorus (P), mycorrhized plants (AMF), and plants that were both fertilized and mycorrhized (P+AMF). The plant height, leaf number, leaf area, fresh biomass (FB), and dry biomass (DB) of the shoots and roots, nutrient content, mycorrhizal colonization (MC), and the number of glomerospores (NG) in the rhizosphere were evaluated. The MC and the NG were reduced by phosphate fertilization. The development of the mycorrhized plants was significantly better than the NI and P treated plants for all of the variables tested. Inoculation with C. etunicatum promoted the growth of P. setacea seedlings even in the absence of phosphate fertilization, reducing production costs and strengthening the potential of P. setacea as a viable agricultural alternative for the semiarid region.     

Behavior of Impatiens wallerana Hook. F in Alternative Pot Substrates: Mechanisms Involved and Research Perspectives

The approach to select new growing media, has been focused on selecting materials only from the physical point of view. The objective of this study was to describe the physiological mechanisms involved in I. wallerana growth when cropped on a broad range of growing media created from alternative components. Results showed a close relationship between I. wallerana growth and fine particle size at the beginning of the experiments. Shoot fresh weight was determined mainly by the root system size. There were small differences in the relative growth rate (RGR) between the control substrate and the thirty alternative substrates tested. The lower RGR values resulted from a decrease in the net assimilation rate and the leaf area ratio. The mechanism involved would be associated with a change in photosynthate partitioning, which favored root growth. A close relationship between growth (as total dry weight) and nitrogen content was found as well.     

Quantification of dwarfing effect of different rootstocks in ‘Picual’ olive cultivar using UAV-photogrammetry

Precision Agriculture - Hedgerow orchard is an olive growing system where trees are planted at a super high-density higher than 20-fold (i.e., 1200–2500 trees ha?1) compared to the...     

Canopy species composition drives seasonal soil characteristics in a Mediterranean riparian forest

European Journal of Forest Research - Mediterranean riparian ecosystems provide key ecosystem services, such as climate regulation, water quality, and flood protection. Forest degradation and...     

Mutations associated with pyrethroid resistance in the honey bee parasite Varroa destructor evolved as a series of parallel and sequential events

Journal of Pest Science - Managed honey bees have suffered severe seasonal losses for most of the past 30 years, while at the same time there is a growing need for food crop pollination....     

Dynamic properties of a flexible net sheet in waves and current—A numerical approach

The dynamic properties of a flexible net sheet exposed to waves and current were investigated by using a numerical model. The net was modelled by dividing it into super elements, and the structural and hydrodynamic forces were calculated for each element. The movement of the net was found from time integrating the equation of motion at each node. The model was used to study the influence of different parameters on the behaviour of the net. Through six different cases the impact of the following five parameters were investigated: (i) floater movement, (ii) wave period/height, (iii) current velocity, (iv) net solidity and (v) bottom weight.     

Inclusion of β-1,3/1,6-glucan in the ornamental fish,Jewel tetra (Hyphessobrycon eques), and its effects on growth,blood glucose,and intestinal histology

The effects of β-1,3/1,6-glucan on Hyphessobrycon eques were assessed after 42 days of feeding diets containing 0 (control group given commercial feed), 0.5, 1, or 2 g β-glucan/kg diet. In total, 180 fish, with an initial weight of 0.43?±?0.03 g, were used. There were 15 fish in each of twelve 42-L aquariums, and there were 3 aquariums of fish for each dietary treatment. The fish were fed until apparent satiety. Performance parameters (final weight, total length, standard length, feed intake, survival rate, weight gain, feed conversion, specific growth rate, and condition factor) and plasma glucose concentration were measured. Histological analysis of the proximal portion of the intestine (width and height of the villi, depth of the crypts, height of the enterocytes, thickness of the muscle layer, and number of goblet cells) was performed. Different levels of the additive did not influence fish performance (for example, final weight: control: 0.63 g, 0.5: 0.60, 1: 0.58, and 2: 0.61). Likewise, there was no influence on the plasma glucose concentration (control: 81.80 mg/dL, 0.5: 75.33, 1: 85.00, and 2: 81.00) and intestinal morphometry of the animals. However, the results showed that 2.0 g/kg of β-1,3/1,6-glucan provided a greater abundance of goblet cells secreting acidic and neutral mucus present in the epithelium (periodic acid-Schiff: 66.67 cells, Alcian blue pH 1.0: 72,67 cells, and Alcian blue pH 2.5: 95.00 cells), showing significant differences when compared to animals in the control group, which may represent better protection of the intestinal epithelium of H. eques.

     

Effect of the interaction between body weight and temperature on growth and maximum daily food intake in sharpsnout sea bream (<Emphasis Type="Italic">Diplodus puntazzo</Emphasis>)

In experimental culture conditions in tanks, the effect of weight (W: 11–452 g) and temperature (T: 14–29°C) on the growth rate (SGR, % bw day⁻¹) and maximum daily food intake (SFR, % bw day⁻¹) in sharpsnout sea bream (Diplodus puntazzo) was studied. The possible combined effect of both independent variables (W and T) was also analyzed by multiple regression analysis, fitting the data to the equation Ln Y = Ln a + b Ln W + cT + dT ² + eT Ln W. Both SGR and SFR, and therefore feed efficiency (FE = SGR/SFR), were significantly influenced by the interaction between temperature and weight and may be expressed by means of the following equations: Ln SGR = −6.1705 + 0.5809T − 0.0087T ² − 0.0249T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.949; ANOVA P < 0.0001); Ln SFR = −4.8257 + 0.4425T − 0.0063T ² − 0.0163T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.964; ANOVA P < 0.0001).The results suggest that the optimum temperature for SGR and FE (T _SGRopt and T _FEopt), and the temperature at which the maximum SFR (T _SFRmax) is reached, decreases with body weight, in accordance with the equations: T _SGRopt = 33.297 − 1.435 Ln W; T _FEopt = 29.332 − 1.890 Ln W; and T _SFRmax = 34.941 − 1.304 Ln W, respectively. In this way, T _SGRopt is 28.4, 26.7, and 24.7°C; T _SFRmax is 30.5, 28.9, and 27.1°C and T _FEopt is 22.9, 20.6, and 18°C for 30, 100 and 400 g body weight, respectively.