A new Aphidius Nees species (Hymenoptera,Braconidae), a parasitoid of Acyrthosiphon malvae (Mosley, 1841) in Europe

Phytoparasitica - Here we describe Aphidius erodii sp. n. associated with Acyrthosiphon malvae (Mosley, 1841), which is a pest on herbaceous ornamental Geranium and Pelargonium plants, but also an...     

Biochar as a strategy to manage plant diseases caused by pathogens inhabiting the soil: a critical review

Phytoparasitica - The current agricultural scenario faces a range of challenges, with phytosanitary ones being paramount. In most cases, plant diseases are treated with chemicals; however, they...     

Lethal and sublethal effects of chemical constituents from essential oils on Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae: Bruchinae) in cowpea stored grains

Journal of Plant Diseases and Protection - The recent use of essential oils has been considered an important approach in pest management programs for stored products. Regarding essential oils, it...     

Evaluation in pot and field trials of resistance of potato cultivars and breeding lines to common scab caused byStreptomyces scabies

Summary The resistance to common scab of nine cultivars and eight advanced breeding lines of potatoes, fiveSolanum andigenum Juz. et Buk. clones, and three potato breeding lines selected for resistance to common scab, was investigated in a field and a pot trial. In the pot trial potaroes were planted in inoculated coarse river sand in plastic pots (150 mm in diameter) placed on irrigated subsoil in a glassfibre house. In a field trial potatoes were planted in an artificially infested field. The harvested tubers were scored individually for scab incidence according to two scales, viz. a 1–5 point scale for percentage surface covered with scab and a 1–3 point scale for lesion type. A scab index value was calculated for each tuber. A significant correlation coefficient of 0.82 was obtained for the results of the two tests.     

Antigenotoxicity and Antioxidant Activity of Acerola Fruit (Malpighia glabra L.) at Two Stages of Ripeness

Genotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract. The antioxidant capacity of substances also showed that unripe samples inhibit the free radical DPPH more significantly than the ripe ones. The results about determination of compounds made using HPLC showed that unripe acerola presents higher levels of vitamin C as compared to ripe acerola. Thus, vitamin C and the complex mixture of nutrients of Malpighia glabra L., and especially its ripeness stages, influenced the interaction of the fruit extract with the DNA. Acerola is usually consumed when ripe (red fruit), although it is the green fruit (unripe) that has higher potential as beneficial to DNA, protecting it against oxidative stress.     

Changes in the content of L-ascorbic acid,glucose, fructose,sucrose and total glycoalkaloids in potatoes (cv. Bintje) stored at 7, 16 and 28°C

Summary We investigated the changes in the content of L-ascorbic acid (L-AA), glucose, fructose, surose and total glycoalkaloids (TGA) during storage of potatoes, cv. Bintje, for 12 weeks at 7,16 and 28°C. The initial amount of L-AA was 8.2 mg/100g fresh weight; after 12 weeks' storage at 7°C it had decreased, while at 16 and 28°C it had increased. The sugar content went up most in potatoes stored at 28°C, but remained below the level at which potatoes taste sweet. The sugar content rose slightly at 16°C, while it decreased in tubers stored at 7°C. The initial TGA content, in equivalent amounts of α-solanine, was 3.6 mg/100 g fresh weight; after 12 weeks' storage it had decreased slightly at all three storage temperatures.     

Variability of in-channel sediment storage in a river draining highly erodible areas (the Isábena,Ebro Basin)

Purpose

In-channel sediment storage is a fundamental component of a river basin’s sediment budget. Sediment remains stored until a competent flow re-suspends and transfers it downstream. The objectives of this paper are: (1) to quantify in-channel sediment storage and its spatial and temporal dynamics in the River Isábena, a mesoscale mountainous catchment draining highly erodible areas (badlands) in the south central Pyrenees (Ebro basin) and (2) to analyse changes in storage in the mainstem channel in relation to sediment yield from the main tributaries.

Materials and methods

In-channel sediment storage was measured seasonally (from winter 2011 to winter 2012) at 14 mainstem cross-sections using a re-suspension cylinder. A minimum of three locations were sampled at each section, and two levels of agitation were applied. Samples allowed determination of the amount of sediment accumulated per unit surface area at a given point in the river; estimates of the total storage in the bed of the mainstem Isábena were derived from these data. In addition, main five tributaries were monitored for discharge and suspended sediment transport.

Results and discussion

Results show an annual sedimentary cycle, with the sediment being produced in badlands during winter, transferred to the main channel during spring, stored in the river during summer and, finally, exported out of the basin by the autumn floods. Marked spatial variability was observed; sections located immediately downstream from the main tributaries (i.e. mainly Villacarli) generally held larger amounts of sediment in the bed. Runoff and sediment inputs from the tributaries were the most important factors determining sediment storage and its spatial and temporal dynamics. The overall sediment yield of the Isábena was much higher than the in-channel sediment storage, despite the large amounts stored in the channel.

Conclusions

This finding corroborates a previous published hypothesis that fine sediment in the drainage network has a mean residence time of the order of 1 year and that the basin’s delivery ratio exceeds 90 %; both of these characteristics can be related to the high connectivity between production areas (badlands) and the river network, and to the role of baseflows allowing continuous export of sediment from the catchment.     

Application of a plant bioassay for the evaluation of ecotoxicological risks of heavy metals in sediments affected by mining activities

Purpose

The objective of this work was to evaluate the effectiveness of a plant bioassay (Phytotoxkit®) for screening ecotoxicological risks in sediments affected by mining activities.

Materials and methods

A total of 42 sediment samples affected by mining activities were studied, including 39 sediment samples from the Sierra Minera, Spain, an area affected by old extraction procedures, and three sediments from an area affected by opencast mining. These three samples were then mixed with limestone filler at 10, 20 and 30 %, providing nine stabilised samples. The total and soluble metal(loid) content (As, Cd, Cu, Fe, Pb and Zn) was determined in all samples, and the Phytotoxkit® bioassay was applied to determine the ecotoxicological effect of this procedure.

Results and discussion

The stabilised material had a neutral pH and low soluble metal(loid) concentration, similar to that of samples in which a natural attenuation process had taken place because of mixing with surrounding carbonate-rich materials. An ecotoxicological survey identified the low toxicity levels of the stabilised samples.

Conclusions

The applied bioassay is a good tool for screening metal(loid) contamination in areas affected by mining activities, since it provides information on both natural and simulated attenuation processes. The mixing of sediments with limestone filler could be applied to the remediation of zones affected by mining activities, because the toxicological effect on the tested organisms in the stabilised sediments was reduced significantly and the metal(loid) content was diminished.     

Genetics components of rice root architecture and carbon isotopic fractionation parameters: a tracer for breeding in a water-saving irrigation management

Journal of Crop Science and Biotechnology - Phenotyping is the major bottleneck in the effort to develop varieties of rice (Oryza sativa L.) suitable for growing under a water-saving irrigation...