Hormone effects on in vitro proliferation and rooting of Grevillea explants

Explants of Grevillea rosmarinifolia A. Cunn. and Grevillea×semperflorens F.E. Brigs ex Mullig., obtained from vegetative stem segments, were grown on a modified MS medium, which was supplemented with different contents of cytokinins (BA or K) to evaluate optimal conditions for bud proliferation. Auxins (NAA or IBA) were tested to evaluate rooting.

The multiplication rate was often higher in G. rosmarinifolia than in G.×semperflorens. Explant activity varied significantly depending on the cytokinin type and its concentration. The addition of cytokinins to the culture medium often promoted an increase in the number of shoots produced by each propagule, but at the highest BA concentration, shoot differentiation was inhibited in Grevillea×semperflorens. Only the higher concentrations studied (5–10 mg/l) produced better results with K, whereas BA was more effective at 1–2 mg/l. Rooting efficiency of the young shoots was lower in G. rosmarinifolia than in G.×semperflorens. IBA promoted root development in both species and was more effective at the highest concentration (1 mg/l). NAA gave better results at low concentrations (0.2 mg/l) in G. rosmarinifolia, while it had slight or negative effect on rooting of G.×semperflorens.     

Antioxidant activities of sicilian prickly pear (Opuntia ficus indica) fruit extracts and reducing properties of its betalains: betanin and indicaxanthin

Sicilian cultivars of prickly pear (Opuntia ficus indica) produce yellow, red, and white fruits, due to the combination of two betalain pigments, the purple-red betanin and the yellow-orange indicaxanthin. The betalain distribution in the three cultivars and the antioxidant activities of methanolic extracts from edible pulp were investigated. In addition, the reducing capacity of purified betanin and indicaxanthin was measured. According to a spectrophotometric analysis, the yellow cultivar exhibited the highest amount of betalains, followed by the red and white ones. Indicaxanthin accounted for about 99% of betalains in the white fruit, while the ratio of betanin to indicaxanthin varied from 1:8 (w:w) in the yellow fruit to 2:1 (w:w) in the red one. Polyphenol pigments were negligible components only in the red fruit. When measured as 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalents per gram of pulp, the methanolic fruit extracts showed a marked antioxidant activity. Vitamin C did not account for more than 40% of the measured activity. In addition, the extracts dose-dependently inhibited the organic hydroperoxide-stimulated red cell membrane lipid oxidation, as well as the metal-dependent and -independent low-density lipoprotein oxidation. The extract from the white fruit showed the highest protection in all models of lipid oxidation. Purified betanin and indicaxanthin were more effective than Trolox at scavenging the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt cation radical. Cyclic voltammetric measurements show two anodic waves for betanin and indicaxanthin, and differential pulse voltammetry shows three anodic waves for betanin, with calculated peak potentials of 404, 616, and 998 mV, and two anodic waves for indicaxanthin, with peak potentials of 611 and 895 mV. Betanin underwent complex formation through chelation with Cu(2+), whereas indicaxanthin was not modified. These findings suggest that the above betalains contribute to the antioxidant activity of prickly pear fruits.     

Physical and chemical quality of ostrich eggs during the laying season

1. Fifteen ostrich females were monitored for a full breeding season. At 30, 70, 110, 150 and 210 d from the beginning of laying, one egg per female was taken to the laboratory to assess its physical and nutritive characteristics. 2. The average length was 15.4 cm, while the width was 12.9 cm. Average shell thickness ranged from 2.20 mm at the equator to 2.24 mm at the small pole. The three principal components of the egg (albumen, yolk and shell) amounted to 57.1, 23.3 and 19.6%, respectively. None of the above variables, despite showing some significant differences between sampling periods, showed a clear trend linked to the laying season. 3. In contrast, the dry matter of the albumen showed a correlation with the sampling period, increasing from 11-1% in the first period to 12.0% in the last. The crude protein content ranged from 47.7 to 48.2%, the fat from 43.8 to 44.2% and the ash between 5.2 and 5.5% of dry matter. 4. The fatty acid composition of the yolk showed the presence of C18:1 (from 122.0 to 136.4 mg/g), followed by C16:0 (from 40.8 to 46.0 mg/g), C18:0 (from 19.2 to 21.2 mg/g) and C18:2 (from 17.1 to 19.6 mg/g). The content of cholesterol/g of yolk was between 10.6 and 10.9 mg. 5. In conclusion, compared with the hen's egg, the ostrich egg has similar chemical and nutritive characteristics, but a higher unsaturated/saturated fatty acid ratio and lower cholesterol content.     

Prediction of rabbit caecal fermentation characteristics from faeces by in vitro gas production technique: roughages

To find equations able to estimate the fermentation characteristics of the caecum from that of faeces, caecal content and faeces of 10 hybrid Hyla rabbits were used as inocula for an in vitro gas production trial. About 1 g of 12 roughages, 11 hays (ryegrass, alfalfa, sulla, oat, vetch, sulla-lolium, vetch-oat, sulla-oat, clover, ryegrass-clover, sulla-vetch-oat) and a wheat straw, was weighed, in triplicate per inoculum, in 120-ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and the flasks were placed at 39 degrees C. Caecal content and faeces were diluted respectively 1:2 (CI) and 1:8 (FI) with anaerobic medium and were introduced into their respective flasks (10 ml). Gas production was recorded 20 times at 2-24 h intervals throughout fermentation (120 h). The fermentation characteristics (i.e. degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, R(max); volatile fatty acid, VFA; ammonia, NH(3)) were studied by inocula and substrates. The two inocula did not differ in OMd but CI produced significantly higher gas (A, 213.1 vs. 199.4 ml/g, respectively, for CI and FI, p < 0.01) in less time (R(max), 3.08 vs. 2.24 ml/h, respectively, for CI and FI, p < 0.01). CI also produced higher levels of total VFA (57.86 vs. 46.70 mmol/g OM, respectively, for CI and FI, p < 0.01) and showed a higher branched chain proportion (0.023 vs. 0.018, respectively, for CI and FI, p < 0.01). For some parameters (as OMd pH and propionate) the equations for the estimation of caecal fermentation characteristics from that of faeces were accurate (R(2) > 0.8828) and reliable (CV < 10.78%) suggesting that faeces can be successfully used for the estimation of these parameters.     

Use of faeces as an alternative inoculum to caecal content to study in vitro feed digestibility in domesticated ostriches (Struthio camelus var. domesticus)

1. In order to find an alternative source of inoculum to caecal content for studying the in vitro feed digestibility in domesticated ostriches (Struthio camelus var. domesticus), caecal content and faeces of 4 male birds were used as inocula for an in vitro gas production trial. 2. About 1 g of each of 5 substrates (maize silage, CS; alfalfa hay, AH; barley, BG; soybean meal, SM; beet pulp, BP) was weighed, in quadruplicate per inoculum, in 120 ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and flasks were kept at 39 degrees C. Caecal content and faeces were diluted respectively 1 : 2 (CI) and 1 : 4 (FI) with an anaerobic medium and were injected into the respective flasks (10 ml). 3. Gas production was recorded 22 times up to 120 h of incubation and fermentation characteristics (for instance, degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, Rmax; time at which it is reached, Tmax; pH; volatile fatty acid, VFA; ammonia) were studied for each inoculum and substrate. 4. CI and FI showed significant differences in Tmax (16.37 vs 18.47 h, respectively), propionic (16.47 vs 12.07 mmoles/l) and butyric acid (6.50 vs 7.98 mmoles/l) and ammonia concentration (17.18 vs 19.95 mmoles/l). The substrates, according to their chemical composition, showed different fermentation characteristics. However, the regression equations able to estimate some fermentation characteristics of the caecum from those of faeces were statistically significant and showed R2-values ranging from 0.87 to 0.99. 5. The differences in fermentation pathways of the two inocula did not appear to influence the rate and extent of OM digestion. Faecal fermentation predicted rates and extent of OM digestion by caecal fermentation in ostriches; consequently, the faeces could be considered as an alternative to caecal content to study feed digestibility in the species, although there is a need to undertake further research.     

Fumigant bioactivity of five Citrus essential oils against Tribolium confusum

During the past decades, the huge use of pesticides caused several environmental problems, so research investigations moved to find a series of compounds with selective toxicity, of a biodegradable and environment-friendly nature, maintaining a positive action in crop and stored products protection. In this perspective, interesting results in the control of pests and fungal pathogens were obtained using essential oils, which are compounds produced by many species of plants as secondary metabolites. The purpose of this research was to evaluate the fumigant activity of five Citrus essential oils against the confused flour beetle Tribolium confusum Du Val, planning a possible employment in the mill industry. The fumigant effectiveness was evaluated 24, 48, 72 hours and 7 days after the start of exposure and each essential oil was analyzed by means of GC and GC/MS. Further evaluations about the toxicity of these compounds were made by partially filling the glass vials with food matrix, in order to assess the possible interference of this matter on the active compounds. The data obtained indicated that, at a low level of fumigant concentration, essential oils can effectively control stored product pests; in the presence of debris, like flour, the efficacy decreased. Plant extracts caused also increased mortality levels after the end of fumigation. The results obtained from this experimentation confirm the efficacy of essential oils in pest control and, in particular, against stored product pests.     

Potato <Emphasis Type="Italic">R1</Emphasis> resistance gene confers resistance against <Emphasis Type="Italic">Phytophthora infestans</Emphasis> in transgenic tomato plants

Tomato is challenged by several pathogens which cause loss of production. One such pathogen is the oomycete Phytophthora infestans which is able to attack all the aerial parts of the plant. Although a wide range of resistance sources are available, genetic control of this disease is not yet successful. Pyramiding R-genes through genetic transformation could be a straightforward way to produce tomato and potato lines carrying durable resistance to P. infestans. In this work the R1 potato gene was transferred into tomato lines. The tomato transgenic lines were analyzed by using q-RT-PCR and progeny segregation to determine the gene copy number. To test the hypothesis that R1 represents a specifically regulated R-gene, transgenic tomato plants were inoculated with P. infestans isolate 88133 and IPO. All the plants containing the R1 gene were resistant to the late blight isolate IPO-0 and susceptible to isolate 88133. These results provide evidence for specific activation of the R1 gene during pathogen challenge. Furthermore, evidence for enhancement of PR-1 gene expression during P. infestans resistance response was obtained.     

Formulation of a new sustainable feed from food industry discards for rearing the purple sea urchin Paracentrotus lividus

The lack of suitable feeds for echinoculture has led to use natural resources already widely exploited by human activities. To move towards a higher sustainability of echinoculture, this study proposes a sustainable feed for Paracentrotus lividus. Two experimental formulations were obtained using discarded endive (Cichorium endivia) leaves and anchovy (Engraulis encrasicolus) industry discards in different proportions, and agar as a binder. The evaluation of the feed stability showed that the feed was stable for 72 hr, allowing a suitable feeding for sea urchins. Both formulations showed a proper nutritional value and fatty acid profile, corresponding to the features of the main ingredients and resulting suitable for echinoculture. A bioenergetic trial was carried out to measure daily ingestion rate, absorption efficiency and gonado‐somatic index in sea urchins. They resulted also palatable and well absorbed by sea urchins, especially that one with higher fish content. At the end of the experiment, an increase in gonado‐somatic index was also recorded. Despite further analysis is needed to assess the performance of the feed in terms of gonad yield and quality, these encouraging results indicate that food industry discards may be suitable alternative ingredients for the production of sustainable feeds for sea urchin aquaculture.