Competitive and allelopathic interference between soybean crop and annual wormwood (Artemisia annua L.) under field conditions

Annual wormwood interference on soybean crop growth and yield may result from competition and allelopathy, which are modulated by crop management. Allelochemicals released by annual wormwood (e.g. artemisinin) may affect the crop directly or indirectly through the effect on the nitrogen fixing symbiont, Bradyrhizobium japonicum. The objectives were (i) to quantify the crop response (i.e. biomass production, nodulation and yield) to weed interference and (ii) to determinate the relative change of competition and allelopathy interferences, when a sublethal dose of herbicide is applied. Two split plot field experiments with three replications were used. The experiment involved a factorial combination of five weed–crop density (soybean/annual wormwood, plants m^?2) levels: D1, pure soybean, 40/0 plants m^?2; D2, 40/2 plants m^?2; D3, 40/4 plants m^?2 and D4, 40/8 plants m^?2, and D5, pure annual wormwood, 0/8 plants m^?2, two activated carbon (allelopathy) levels: C?, with activated carbon (reduced allelopathy) and C+, non activated carbon applied (with allelopathy) and two herbicide levels: H?, untreated and H+, treated with a sub-lethal dose of glyphosate. Activated carbon to adsorb allelochemicals (with and without activated carbon) and glyphosate application (with and no herbicide) were assigned to sub-plots. Increasing weed density did not affect crop biomass at flowering, but changed nodule number and soybean yield with a different pattern depending on carbon and herbicide treatment. Relative crop yield decreased with increasing relative weed biomass. This decrease was particularly drastic when allelopathy was reduced by activated carbon and without herbicide application. The maximum yield losses of 33% in 2006 and 17% in 2007 were observed with the highest weed density (8 plants m^?2). In contrast, without carbon (high allelopathy level), soybean yield remained stable within the explored range of annual wormwood biomass, despite the fact that weed biomass at high densities (D4) was high enough to generate competition. The lack of response to increasing weed density could be related to the indirect effect of allelochemicals interacting with soil microorganisms (i.e. B. japonicum) that positively affected the nodulation (e.g. larger nodules in 2006 and increased nodules biomass due to higher number of roots in 2007 at high densities). With herbicide application, soybean yield of both carbon treatments remained stable when biomass of annual wormwood increased. This research provided strong evidence in support of the existence of positive effect of allelopathic and competitive interactions between annual wormwood and soybean crop under field conditions that may be overridden under herbicide application.     

Morphological characterization of the IVIA persimmon (Diospyros kaki Thunb.) germplasm collection by multivariate analysis

Diospyros kaki Thunb. originated in Eastern Asia, as evidenced of its culture in China as early as several centuries B.C. In the seventh century, persimmon was introduced to Japan and later, in the fourteenth century to Korea. There is no information about persimmon culture in Europe until the seventeenth century, with the spread over the world occurring in the eighteenth century. The genus Diospyros contains more than 400 species, with levels of ploidy ranging from diploid (2n = 2x = 30) up to nonaploid (2n = 9x = 135). The primary economic crop species is Diospyros kaki Thunb., which is mainly hexaploid (2n = 6x = 90) and includes hundreds of cultivars. Although a relatively recent introduction in Europe, the species has adapted well, and the genetic diversity have been expanded with culture and selection for the past 200 years in the Mediterranean basin. These locally adapted cultivars were evaluated with cultivars from Asian origin in a germplasm collection established at IVIA in Valencia, Spain. In this paper 27 cultivars from the IVIA collection were studied by multivariate analysis, and 37 variables were analyzed using a Principal Components Analysis and cluster analysis following the method UPGMA. Studies on correlations and significance among variables identified the most relevant ones, and thus provided information for a future core collection.     

Note:Syringopais temperatella Lederer, 1855 and its parasitoids in wheat and barley fields in the southeast Anatolian region of Turkey

Larvae of the cereal leaf minerSyringopais temperatella Led. (Lep.: Scythridae) collected from wheat and barley fields in the southeast Anatolian region of Turkey during 2005–2006, and their parasitization rates, were determined in the laboratory,Bracon (Habrobracon) stabilis Wesmael andApanteles sp. (Hymenoptera: Braconidae) were identified as its parasitoids for the first time.     

Contamination of soil with Toxocara eggs in urban (Prague) and rural areas in the Czech Republic

Contamination of soil with feline and canine ascarid eggs in public parks, backyards and sand pits in Prague, Czech Republic was investigated in this work. Soil samples from shelters and rural areas were also collected. The comparison of soil from different areas (urban, rural, backyards and shelters) exhibited significant difference (chi(2)=32.16, d.f.=3 and p<0.0001). The highest rate of contamination (45%) was found in backyards inhabited by feral cats. The eggs of Toxocara spp. were found in 20.4% of parks, 10% of shelters and 5% of rural samples. Mean egg density per sample from Prague parks was 6.2 eggs/100g of soil. In 126 composite samples from children's and pits, the prevalence of Toxocara eggs was 11.90%. The number of eggs in positive samples varied from 2 to 22 (per 100g). A high proportion (46.9%) of eggs was fully embryonated. There was no difference between the sand pits with or without formal exclusion of dogs (chi(2)=0.6, d.f.=1 and p<0.0001).     

Assessment of the Nutritional Value of Traditional Vegetables from Southern Chile as Potential Sources of Natural Ingredients

Plant Foods for Human Nutrition - There is an increasing interest in consuming healthy foods motivated by the need of boosting the immune system naturally. In this sense, vegetables rich in...     

Dual-label time-resolved fluoroimmunoassay for simultaneous quantification of haptoglobin and C-reactive protein in meat juice from pigs

A new method was developed to simultaneously measure 2 acute-phase proteins (APPs) by time-resolved immunofluorometry. The assay, based on double-label quantification of haptoglobin (Hp) and C-reactive protein (CRP) in meat juice samples from pigs, was constructed by use of a combination of europium and samarium chelate lanthanides as labels. Meat juice samples from 154 pigs were used for analytic and clinical validation of the assay through determination of precision, accuracy, limit of detection, and quantification. The analytic performance of the assay was satisfactory, with good intra-assay and interassay precision and accuracy. The levels of Hp and CRP were increased in the meat juice samples of diseased animals compared with healthy ones. According to the results, higher sensitivity could be achieved if the cut-off values of both proteins were taken into account for clinical relevance rather than used individually. Since the dual assay saved both time and sample, it could be used as a rapid and sensitive screening test in porcine production.     

Effects of various densities of Ophiostoma ips inoculations on Pinus sylvestris in north‐western Spain

The aim was to determine the inoculation density above which Scots pine (Pinus sylvestris) is overcome by the blue‐stain fungus Ophiostoma ips that is associated with the bark beetle Ips sexdentatus. In north‐western Spain, stems of 16 Scots pines were inoculated at various densities (0, 400, 800 or 1600 inoculi/m²) along circumferential 100 or 150 cm wide inoculation belts. Each inoculum consisted of a 5 mm diameter cylinder of malt extract agar colonized by the fungus. Three months later, all trees were harvested and trunk resinosis and foliage colour were visually assessed. The percentage of healthy, desiccated, resin soaked, and blue‐stained sapwood, as well as growth productivity indices, were calculated from stem disks cut from within the inoculated zone of each tree. Sapwood‐specific hydraulic conductivity (Ks) of each tree was measured in the middle of the inoculated zone. All parameters of tree vigour changed dramatically to the worse when inoculation densities were above 400 inoculi/m², and foliage changed from green to yellow‐green or yellow when an inoculation density of 800 instead of 400 was used. The percentage loss of sapwood‐specific conductivity (PLC) increased from 30 to 90% and the percentage of healthy, conductive sapwood dropped from 85 to 35% at 800 inoculi/m². No effect of the width of the inoculation belt was observed, and there was no relationship between tree productivity indices and the level of resistance. A non‐linear negative relationship was found between PLC and the percentage of healthy sapwood. It is concluded that tree resistance was overcome and that trees were going to die when the inoculation density was ≥800 inoculi/m².     

Soil evolution over the Quaternary period in a semiarid climate (Segre river terraces,northeast Spain)

A macro- and micromorphologic study was done on the soils from a stepped sequence of seven dated fluvial terraces in the lower Segre river valley (Lleida, northeast Spain) under a present-day semiarid Mediterranean climate. The soils have evolved from the Holocene through the early Pleistocene, providing an excellent morphostratigraphic framework for evaluating time-dependent factors influencing soil formation in a dry and calcareous environment. Throughout the chronosequence, some properties are regularly age-related specially carbonatation in subsurface horizons. The carbonates occur mainly as micrite, and although microsparite and sparite also appear in the oldest soils, they are replaced by fine-grained calcite by dissolution–reprecipitation processes (micritization process), which is active at present. Some pedological paleofeatures as the presence of sparite and recarbonated argillans in oldest terrace can be interpreted as the reflex of climatic changes during the Quaternary. In spite of this climate variability, the soils display progressive and systematic patterns of carbonate accumulation: on the lowest terraces, the soils do not yet have secondary carbonates but in the beginning Late Pleistocene calcic horizons, with carbonate pendents, are developed; these pendents increase its thickness with age although pendent growth rates decreases from Late Pleistocene to Middle Pleistocene. In the middle of the Late Pleistocene, calcic horizons evolved to petrocalcic horizons, which increase its thickness in the Middle and specially in Early Pleistocene. The presence of calcic and petrocalcic horizons is the primary basis for soil classification. This criterion is applicable not only to the soils of the lower Segre river basin, but also to many soils throughout the semiarid Mediterranean region.     

一些优质小麦及其杂种后代高分子量谷蛋白亚基组成与面包品质之关系

应用ＳＤＳ－ＰＡＧＥ技术分析了陕优２２５等１６个品种及３个组合杂种后代分离材料高分子量谷蛋白亚基组成及与面包品质的关系。结果表明，普通小麦中罕见的Ｇｌｕ－Ｂ１编码来基１４＋１５象Ｇｌｕ－Ｄ１编码亚基５＋１０一样，对面包品质有重要贡献，存在于陕优２２５、小偃６号等优质品种中。     

Ecological impacts of small hydropower plants on headwater stream fish: from individual to community effects

Hydroelectricity is increasingly used worldwide as a source of renewable energy, and many mountain ranges have dozens or hundreds of hydropower plants, with many more being under construction or planned. Although the ecological impacts of large dams are relatively well known, the effects of small hydropower plants and their weirs have been much less investigated. We studied the effects of water diversion of small hydropower plants on fish assemblages in the upper Ter river basin (Catalonia, NE Spain), which has headwater reaches with good water quality and no large dams but many of such plants. We studied fish populations and habitat features on control and impacted reaches for water diversion of 16 hydropower plants. In the impacted reaches, there was a significantly lower presence of refuges for fish, poorer habitat quality, more pools and less riffles and macrophytes, and shallower water levels. We also observed higher fish abundance, larger mean fish size and better fish condition in the control than in impacted reaches, although the results were species‐specific. Accordingly, species composition was also affected, with lower relative abundance of brown trout (Salmo trutta) and Pyrenean minnow (Phoxinus bigerri) in the impacted reaches and higher presence of stone loach (Barbatula quignardi) and Mediterranean barbel (Barbus meridionalis). Our study highlights the effects of water diversion of small hydropower plants from the individual to the population and community levels but probably underestimates them, urging for further assessment and mitigation of these ecological impacts.