European hazelnut (Corylus avellana L.) is an emerging crop for export, mainly in southern Chile. Stem cankers and dieback of twigs on sixyear-old European hazelnut cultivar Barcelona were observed during the 2012 growing season on plantations in Panguipulli (39° 38' 37.12" S and 72° 20' 10.87" W), Region de Los Rios, Chile. The incidence has been variable according to the place of plantation; it was estimated at approximately 15%. Cankers were characterized by brownish-gray and brown to reddish discoloration of the vascular stem system. Hazelnut plants between 1 and 3 years old developed stem basal canker, especially at conditions of high humidity and overpopulation of weeds; at critical conditions, the affected plants generally die. Small pieces of cankered stems, selected from 10 European hazelnuts, were surface sterilized in 0.5% sodium hypochlorite for 2 min and rinsed twice in sterile distilled water prior to incubation in a humid chamber for 7 days (25 ± 2°C) to stimulate production of reproductive bodies. Black sub-epidermal perithecia with unitunicate, cylindrical-clavate, 8-spored asci {n = 20) were obtained. Ascospores were septated, hyaline, multigutulate, and slightly constricted at the septum, the average measurements were (n = 20) 13.4 ± 0.6 |am x 3.9 ± 0.2 (im. The ascospores were transferred to potato dextrose agar (PDA) and incubated for 6 days at 25°C in the dark, then hyphal tips were transferred to fresh PDA and obtained a mycelia with white, cottony, and sparse colonies. Pycnidia and smooth, unicellular, hyaline, and biguttulate alpha conidia of 6.1 to 7.2 |am x 2.8 to 3.1 |jm (n = 40) were observed. Beta conidia were not observed in culture media. Mature pycnidia were also detected on hazelnut shells remaining on the soil from the previous season. The identification of the species (isolate IMI-501237) was confirmed at CABI, United Kingdom, using an internal transcribed spacer (ITS), rDNA, BLASTn analysis of the 524-bp fragment, and showed 100% identity with Diaporthe australafricana Crous & J.M. van Niekerk (accessions KC343039, KC343038). These molecular and morphological characteristics were similar that reported from Vitis vinifera (2) and Chilean blueberry (3). The sequence obtained was deposited in GenBank (Accession No. JX3162I8.I). A pathogenicity test was conducted with isolate IMl-501237 on four 1-year-old plants from the hazelnut cultivar Barcelona. Plants were maintained in individual bags in greenhouse conditions (14/10 h dark/light, 20°C; 70% relative humidity). Prior to inoculation, plant tissues were surface disinfected with 2% sodium hypochlorite and rinsed with sterile distilled water. Each plant was inoculated at fresh wound sites on three stems and three vegetative buds on twigs. The inoculum consisted of an agar plug with mycelia (5 mm) from the edge of an actively growing colony cultured on PDA for 6 days. Each inoculation was covered with moistened cotton and sealed with Parafilm; a control plant was inoculated in the same way with agar only. After 30 days, necrotic le...
Background: Sugarcane is widely consumed by people of the tropics and subtropics. Antioxidants in concentrated sugarcane extracts extracted from sugarcane products using resins are highly stable, and their antioxidant activity is not significantly reduced by prolonged heating or clarification. Methods and Results: This study investigated the extraction processing and evaluated the antioxidant action (DPPH, ABTS, and FRAP) of sugarcane extracts. The total phenolic content and the phenolic composition of sugarcane extracts were analyzed. Our results showed that the sugarcane extracts were potential source of antioxidant compounds. The total phenolic content in sugarcane extracts was 0.179 ± 0.003 mg equivalent/gram extracts. The major phenolic acids in sugarcane extracts were identified and quantified using high performance liquid chromatography (HPLC). The content of gallic acid, chlorogenic acid, caffeic acid, and ferulaic acid in sugarcane extracts were (0.87mg/g), (1.77mg/g), (11.64mg/g), and (10.49mg/g), respectively. Conclusion: This study provides a basis for further exploitation of the health beneficial resources of sugarcane.
Abstract:The chemical composition of riverine suspended sediment is the integration of the weathering crust minerals, soil organic matter and erosion agency within a specific drainage basin, which has been largely disturbed by the human activities. Selected metal elements of the riverine suspended sediment in the Zhujiang River were analysed using inductively coupled plasma-atomic emission spectrometry (ICP-AES) in three different hydrological phases from 1997 to 1998 at Makou and Sanshui hydrographic gauge stations, located at the lower reaches of the two main tributaries of the Zhujiang River, i.e. the Xijiang and the Beijing Rivers respectively. Organic carbon and nitrogen were also analysed using a conventional element analyser. The results demonstrate that the chemical composition of the riverine suspended sediment show obvious variability in different hydrological phases, which closely correlate to the organic matter content in suspended sediment. Intensified erosion in the flood phase results in lower concentration of the organic matter than that in the lower water level phase. The riverine suspended sediment with rich organic matter in the lower water level phase adsorbs some metal elements from the river water.
Microplastics (MPs) have a great potential to adsorb heavy metal pollutants such as Pb2+ and the dissolved organic matter(DOM) in the aquatic environment will affect this adsorption behavior. In this study, batch experiments were performed to investigate the adsorption characteristics of Pb2+ onto polystyrene microplastics (PSMPs) in the presence and absence of HA(a kind of representative DOM). The adsorption kinetics of Pb2+ onto PSMPs conformed to the pseudo-second order model, and the adsorption isotherms were well fitted by the Langmuir model. With the increase of HA concentration, the Pb2+ adsorption onto PSMPs increased. Site energy distribution analysis showed that the presence of HA increased the adsorption site energy of PSMPs, thus enhancing the adsorption capacity for Pb2+. The fluorescence quenching analysis of HA further indicated that part of HA were adsorbed onto PSMPs, which increased additional binding sites on the surface of PSMPs. This was attributed to the abundant functional groups that could react with Pb2+ of HA. The pH and ionic strength of solution changed the structure of HA and the adsorption sites of PSMPs, which influenced the adsorption capacity of PSMPs for Pb2+. This study illustrated the effect of HA on the process and mechanism of Pb2+ adsorption onto PSMPs, and provided more information for the evaluation of environmental behavior and toxicological effects of microplastics in aquatic environments.
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