Improved efficiency of in vitro propagation of Camellia reticulata cv. Captain Rawes

Effects of various factors were studied on the in vitro multiplication and rooting of a clone of Camellia reticulata cv. Captain Rawes established in vitro from shoots of an adult tree. Multiplication rates were increased by repeated harvesting of cultures in which shoots were subcultured in a horizontal rather than a vertical position. Best rooting responses were obtained with 175.3 mM sucrose in the rooting medium using 8 week old shoots cultured in 500 ml glass jars; these shoots contained more anthocyanin than those from test-tube cultures. The orientation and repeated harvesting of the mother shoots had no effect on rooting response.     

Determination of baseline susceptibility of European populations of Tuta absoluta (Meyrick) to indoxacarb and chlorantraniliprole using a novel dip bioassay method

BACKGROUND: Tuta absoluta(Meyrick) is one of the most serious pests of tomato recently introduced in the Mediterranean region. A novel bioassay method designed for the accurate determination of insecticide toxicity on T. absoluta (IRAC method No. 022) was validated by three different laboratories [Greece (NAGREF), Italy (UC) and Spain (UPCT)] on European populations. RESULTS: The insecticides indoxacarb and chlorantraniliprole were used as reference products. The IRAC leaf dip method is easy to perform, producing repeatable, homogeneous responses. LC₅₀ values for indoxacarb ranged between 1.8 and 17.9 mg L^?1 (NAGREF), 0.93 and 10.8 mg L^?1 (UC) and 0.20 and 0.70 mg L^?1 (UPCT), resulting in a tenfold, 12‐fold and fourfold difference between the least and most susceptible populations at each laboratory respectively. For chlorantraniliprole, LC₅₀ values ranged between 0.10 and 0.56 mg L^?1 (NAGREF), 0.23 and 1.34 mg L^?1 (UC) and 0.04 and 0.24 mg L^?1 (UPCT), resulting in a sixfold difference in all three cases. Overall, UPCT reported lower mean LC₅₀ to indoxacarb, while UC reported higher LC₅₀ to chlorantraniliprole. CONCLUSIONS: The new bioassay is reliable, providing a useful tool in the design of IRM strategies. Within each country/lab, the variability observed in the results for both indoxacarb and chlorantraniliprole can be attributed to natural variation. Future research is necessary to determine the extent to which it is possible to compare results among laboratories. Copyright © 2012 Society of Chemical Industry     

Characterization of Swine Wastewater by Toxicity Identification Evaluation Methodology (TIE)

Since swine wastewater is used by farmers for soil fertilization, evaluation of toxic compounds or micro-contaminants of separate streams is required. This paper uses the toxicity identification evaluation (TIE) procedure for the physicochemical and ecotoxicological characterization of swine wastewater. To distinguish the most important toxic compounds, a physicochemical characterization and phase I-TIE procedure were performed. The acute toxic effect of swine wastewater and treated fractions (phase II-TIE) were evaluated using Daphnia magna determining 48-h LC₅₀. Results show a high level of conductivity (23.5 μS cm⁻¹), which is explained as due to the concentration of ions, such as ammonium (NH₄⁺–N 1.6 g L⁻¹), sulfate (SO₄²⁻ 397.3 mg L⁻¹), and chlorine (Cl⁻ 1,230.0 mg L⁻¹). The acute toxicity of the swine wastewater was evaluated on D. magna (48-h LC₅₀ = 3.4%). Results of the different water treatments indicate that anionic exchange treatments could reduce 22.5% of swine wastewater’s acute toxicity by reducing chlorine (to around 51%) and conductivity (8.5%). On the other hand, cationic exchange treatment increased acute toxicity on D. magna (% RT = −624.4%), by reducing NH₄⁺–N (around 100%) and total nitrogen (95.5%). This finding suggests that part of the toxicity comes from anionic compounds, such as chlorine.     

Growth performance and expression of immune‐regulatory genes in rainbow trout (Oncorhynchus mykiss) juveniles fed extruded diets with varying levels of lupin (Lupinus albus), peas (Pisum sativum) and rapeseed (Brassica napus)

Varying levels of lupin (Lupinus albus), peas (Pisum sativum) and rapeseed (Brassica napus) meals were evaluated as partial replacements for fishmeal in extruded diets for rainbow trout, with particular emphasis on the effect on growth performance and the expression of three genes associated with immune response. A series of 10 isonitrogenous (450 g kg^?1 crude protein) and isolipidic (17 g kg^?1 crude lipid) diets were formulated to contain different levels of lupin (150 g kg^?1, 250 g kg^?1 and 350 g kg^?1), rapeseed cake (100 g kg^?1, 200 g kg^?1 and 300 g kg^?1) and pea (50 g kg^?1, 150 g kg^?1 and 250 g kg^?1) meals. The control diet was prepared with fish meal as the sole source of protein. Triplicate groups of fish (37.08 ± 3.58 g) were assigned to each experimental diet. The feeding experiment was conducted for 9 weeks at 14.3 ± 0.4 °C. The fish were hand fed three times per day, 6 days per week to apparent satiation level. Growth performance, feed utilization and immunological response were significantly affected by the type of plant protein as well as level of inclusion. Hepatosomatic index (HSI) increased in all groups of fish fed diets with pea and rapeseed cake meal. Dietary inclusion of lupin did not affect the expression of Mx‐1 gene. Our results suggest that fish meal can be replaced by lupin in the diet of rainbow trout without any apparent adverse effects on key innate immunological genes.     

A new tool for determining the optimum fish meal and vegetable meals in diets for maximizing the economic profitability of gilthead sea bream (Sparus aurata,L.) feeding

The economic profitability of fish meal replacement by soybean meal and pea‐rice concentrate mixture, was analysed considering the economic conversion ratio (ECR) and the economic profit index (EPI_st) as a proposal for evaluating the economic profitability in diets for sea bream. The optimal fish meal levels for minimizing the ECR were 33% (when soybean meal was included) and 14% (in the case of pea‐rice concentrate mixture) and for maximizing the EPI_st, optimal fish meal levels were 31% and 28.8%, respectively, considering the current market price of fish meal and vegetal ingredients. The EPI_st, seems to be a better index than the ECR to estimate diet profitability, because it considers weight increment, feed conversion ratio, diet cost and fish sale price. A sensibility analysis was conducted, considering variations in the price of fish meal and vegetal ingredients. Finally, several multiple regressions were developed for estimating the optimal level of fish meal with each vegetable ingredient and the expected value of the economic profit as a function of the market price of both fish meal and plant protein. When fish meal prices increase, the highest beneficial level of the inclusion fish meal and the highest economic profit would be achieved with pea‐rice mixture.     

Germ‐Derived FAN as Nitrogen Source for Corn Endosperm Fermentation

Corn endosperm separated by dry fractionation could exhibit poor fermentation performance due to loss of germ components beneficial for yeast growth. Inorganic nitrogen and other nutritional supplementations are used to overcome slow fermentation rates. We investigated the use of a protease in generating free amino nitrogen (FAN) from germ as an alternative to exogenous nitrogen sources. Up to 300% more FAN can be generated from germ in 6 hr of incubation with protease than without protease. Protease incubation also resulted in higher dry solids (ds) and total glucose contents in the germ hydrolyzates. During fermentation without urea addition, ethanol yields were dependent on mash FAN concentrations. Ethanol yields increased to a maximum when FAN level was 80–90 mg of FAN/100 g ds. At half the optimal FAN level (≈40 mg of FAN/100 g ds), nitrogen limitation occurred, as indicated by high residual glucose concentrations. However, germ FAN did not increase the ethanol yields compared to urea supplementation, likely because germ FAN resulted in lower substrate consumption compared to urea supplementation. Lower substrate consumption correlated to the increase in residual maltose with increase in initial FAN. Ethanol productivity in 0–24 hr of fermentation was higher with germ FAN than with urea, thus decreasing overall fermentation time.     

Influence of digestible protein levels on growth and feed utilization of juvenile meagre Argyrosomus regius

This study investigates the effect of digestible protein levels in experimental diets for meagre (Argyrosomus regius). A group of 253 fish, 52 g of mean weight, was distributed in 12 tanks, three replicates per treatment. Four isolipidic diets (170 g kg^?1 crude lipid) with different digestible protein levels (350 g kg^?1, 430 g kg^?1, 490 g kg^?1 and 530 g kg^?1) were formulated using commercial ingredients. The trial lasted 62 days. Meagre fed diets 430, 490 and 530 g kg^?1 obtained higher TGC (2.47, 2.57, 2.69 × 10^?3, respectively) than fish fed diet 350 g kg^?1 (2.14 × 10^?3). Group of fish fed diet with 350 g kg^?1 DP showed the lowest ammonia excretion level. According to the in vitro digestibility trial diets with 350 and 430 g kg^?1 DP released less amino acids in comparison with diet with 49% DP, although in vivo digestibility test did not show significant differences among diets 430, 490 and 530 g kg^?1 DP. Using the quadratic regression, optimal digestible protein intake according to the ECR for rearing juvenile meagre was recorded in 0.8 g DP/100 g fish and day.