The interaction of two potential fungal bioherbicides and a sub-lethal rate of glyphosate for the control of shattercane

Greenhouse and laboratory experiments were conducted with the potential bioherbicides Colletotrichum graminicola (Cg) and Gloeocercospora sorghi (Gs) for control of shattercane weed. Single-spray tank mixture applications containing different ratios of the two fungi resulted in additive percent weed biomass losses. Intraspecific (Cg + Cg or Gs + Gs) and interspecific (Cg + Gs or Gs + Cg) sequential applications 1- or 7-days apart indicated antagonistic interactions in percent biomass loss. Application of either fungus with, or 1–3 days prior to, a sub-lethal concentration of glyphosate resulted in an antagonistic percent biomass loss; while application of glyphosate prior to either potential bioherbicide resulted in a synergistic weed disease response. Conidia germination studies conducted both in vitro on agar plates and with leaf impression peels suggest that antagonistic interactions observed in weed disease severity are probably due to the host–pathogen response following infection.     

镉胁迫下硒对罗汉果组培苗光合特性的影响

实验以罗汉果组培苗为材料,室内栽培在内装市售营养土的塑料盆中,以0、10、50、100、200mg·kg-1浓度镉离子和1mg·kg-1浓度硒处理,培养20d后分析罗汉果幼苗的相关光合生理指标。结果表明:低浓度Cd2+对叶片叶绿素含量、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)影响不大或稍有上升,但高浓度镉离子处理植株叶片的叶绿素含量、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)明显下降;随Cd2+处理浓度的增加,叶片胞间CO2浓度(Ci)呈现上升趋势;加硒则延缓叶绿素下降,促进光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)上升,降低叶片胞间CO2浓度(Ci)。表明高浓度镉离子的毒害导致罗汉果组培苗叶片光合性能受到伤害,从而影响罗汉果幼苗生长。镉硒混合处理反映出硒对镉的毒害有缓解作用。     

Photosynthetic capacity of field-grown durum wheat under different N availabilities: A comparative study from leaf to canopy

The effect of N availability on photosynthetic capacity, growth parameters and yield was studied in field-grown durum-wheat plants at both the leaf and canopy levels. Two contrasting nitrogen levels (120 and 0 kg ha^?1) were assayed in a randomised block design with nine replicates each. Total biomass was measured at anthesis and yield and its agronomical components at maturity. Photosynthetic measurements were performed 2 weeks after anthesis in two plots of each N treatment. Flag leaves were measured, using a LI-COR 6400 combined with the chlorophyll fluorescence meter, and the whole canopy by measuring CO₂ and H₂O fluxes in an innovative canopy-chamber system. We showed a clear increase in photosynthetic gas exchange and chlorophyll contents with N fertilisation at both canopy and leaf levels. As a consequence the increase in yield as response to N fertilisation seems the result of a larger green leaf area combined with a higher photosynthetic capacity of the leaves attributable to an increase in the maximum carboxylation velocity of Rubisco. Moreover gas-exchange measurements of the flag leaf during grain filling seem to provide a realistic characterisation, not just of the photosynthetic performance of the crop, but also about the impact of N availability on yield. Thus, measurements performed on the flag leaf matched those at the canopy level, with proportional increases in terms of gas exchange and chlorophyll content, providing a fast, cheap and reliable estimation of canopy photosynthesis and the grain yield attained by the crop.     

Agro-morphological characterization and assessment of variability,heritability, genetic advance and divergence in bacterial blight resistant rice genotypes

Genetic based knowledge of different growth traits including morphological, physiological and developmental plays fundamental role in the improvement of rice. Genetic divergence allows superior recombinants which are essential in any crop development project. Forty-one rice genotypes including bacterial blight (BB) resistant and susceptible checks were assessed for 13 morphological traits. Among the genotypes, almost all the traits exhibited highly significant variation. The higher extent of genotypic (GCV) as well as phenotypic coefficients of variation (PCV) were noticed for number of tillers hill^− 1, total number of spikelets panicle^− 1, number of filled grains panicle^− 1, and yield hill^− 1. High heritability together with high genetic advance was observed for total number of spikelets panicle^− 1, number of filled grains panicle^− 1, and yield hill^− 1 indicating dominant role of additive gene action in the expression of these traits. Number of filled grains panicle^− 1 exhibited positive correlation with most of the traits. Yield hill^− 1 showed a good number of highly significant positive correlations with number of filled grain panicle^− 1, total number of spikelets panicle^− 1, 1000 grain weight hill^− 1, number of panicle hill^− 1, and panicle length. The UPGMA dendrogram divided all the genotypes in to six major clusters. The PCA showed 13 morphological traits generated about 71% of total variation among all the genotypes under this study. On the basis of 13 morphological traits, genotypes such as IRBB2, IRBB4, IRBB13, IRBB21, and MR263 could be hybridized with genotypes MR84, MR159, MRQ50, MRQ74, PH9 and IR8 in order to develop suitable BB resistant rice genotypes.     

Hormones in the grains and roots in relation to post-anthesis development of inferior and superior spikelets in japonica/indica hybrid rice

Grain filling is usually not adequate in later-flowering inferior spikelets in japonica/indica (J/I) hybrid rice (Oryza sativa) although it shows stronger hybrid vigor than indica/indica (I/I) hybrid. This study investigated the potential causes by examining changes in zeatin (Z) + zeatin riboside (ZR), indole-3-acetic acid (IAA), gibberellins (GAs, GA₁ + GA₄), and abscisic acid (ABA) in spikelets and roots during the grain filling period. The inferior spikelets of J/I hybrid exhibited low rate of endosperm cell division and slow grain filling. During the early grain filing period, they had less Z + ZR, IAA, and ABA, but more GAs, than the earlier-flowering superior spikelets. If compared to the inferior spikelets of the I/I hybrid, the J/I inferior spikelets also had less Z + ZR, IAA, and ABA. Rates of endosperm cell division and grain filling were positively and significantly correlated with Z + ZR and ABA contents in both grains and roots or IAA in grains, whereas not significantly correlated with GAs either in grains or roots or IAA in roots. Applications of kinetin, IAA, or ABA to spikelets, or kinetin and ABA to roots, enhanced cell division and grain filling in the inferior spikelets. Results suggest that low contents of cytokinins and ABA in both grains and roots and low contents of IAA in grains may result in the poor filling of inferior spikelets in the J/I hybrid.     

A novel SNP of the GHRL gene in goat and its association with growth traits

Ghrelin, an endogenous gland for growth hormone secretagogue receptor, has been shown to stimulate food intake and control energy homeostasis and lipid metabolism. So, ghrelin precursor (GHRL) gene is a potential candidate gene for caprine growth traits. In this study, we detected the polymorphism of the caprine GHRL gene by PCR–SSCP and DNA sequencing methods in 459 individuals from four goat breeds. A novel single nucleotide polymorphism (SNP) (IVS2 + 147G > A) was detected. Frequencies of IVS2 + 147G allele varied from 0.842 to 1.000. The association of IVS2 + 147G > A with growth traits was analyzed and IVS2 + 147G > A was shown to be associated with growth traits. Individuals with genotype AG were significantly higher than those of individuals with genotype GG in circumference of chest and cannon and trunk index (P < 0.05 or P < 0.01). Moreover, there was a tendency that genotype AG individuals had better performance in other aspects such as body height and body length than genotype GG individuals although no significant differences appeared (P > 0.05). We suggested that IVS2 + 147G > A could be a perfect molecular marker in marker-assisted selection (MAS).     

Estimation of genetic parameters for post-weaning traits of Kermani sheep

The objective of the present study was to estimate genetic parameters for post-weaning traits in Kermani sheep. Traits were included 6-month weight (6MW), 9-month weight (9MW), yearling weight (YW), greasy fleece weight at first shearing (GFW) and greasy fleece weights at various shearings (RFW). Data and pedigree information used in this research were collected at Breeding Station of Kermani sheep during 1993–2004. Genetic parameters were estimated with single- and multi-traits analysis using restricted maximum likelihood (REML) procedures, under animal models. Log likelihood ratio test indicated the most appropriate model for 6MW and 9MW should included direct additive genetic effects as well as maternal permanent environmental effects. However the most appropriate model for YW and GFW had only the direct additive genetic effects. The effects of sex, age of dam and year of birth were significant on body weight traits (P < 0.01). GFW was influenced significantly by sex and year of birth (P < 0.01) but was not affected by age of dam (P > 0.05). Type of birth was no significant effect on studied traits (P > 0.05). Also, the age of lamb at weighing time was a significant influence on 6MW, 9MW and YW. Direct heritability estimates for 6MW, 9MW, YW and GFW were 0.32, 0.03, 0.15 and 0.15, respectively. Maternal permanent environmental estimates of 0.09 were obtained for 6MW and 9MW. Genetic correlation estimates between mentioned traits ranged from 0.51 to 0.99. Phenotypic correlations were generally lower than those of genetic correlation and varied from 0.05 to 0.79 for various traits. The environmental correlations estimates between GFW with growth traits were low, but between other traits were positive and high, ranged from 0.54 to 0.72. The value of repeatability estimated for greasy fleece weight was 0.22.     

Alleviating the adverse effects of NaCl stress in maize seedlings by pretreating seeds with salicylic acid and 24-epibrassinolide

The effects of bio-regulators salicylic acid (SA) and 24-epibrassinolide (EBL) as seed soaking treatment on the growth traits, content of photosynthetic pigments, proline, relative water content (RWC), electrolyte leakage percent (EC%), antioxidative enzymes and leaf anatomy of Zea mays L. seedlings grown under 60 or 120 mM NaCl saline stress were studied. A greenhouse experiment was performed in a completely randomized design with nine treatments [control (treated with tap water); 60 mM NaCl; 120 mM NaCl; 10^− 4 M SA; 60 mM NaCl + 10^− 4 M SA; 120 mM NaCl + 10^− 4 M SA; 10 μM EBL; 60 mM NaCl + 10 μMEBL or 120 mM NaCl + 10 μM EBL] each with four replicates. The results indicated that NaCl stress significantly reduced plant growth traits, leaf photosynthetic pigment, soluble sugars, RWC%, and activities of catalase (CAT), peroxidase (POX) as well as leaf anatomy. However, the application of SA or EBL mitigated the toxic effects of NaCl stress on maize seedlings and considerably improved growth traits, photosynthetic pigments, proline, RWC%, CAT and POX enzyme activities as well as leaf anatomy. This study highlights the potential ameliorative effects of SA or EBL in mitigating the phytotoxicity of NaCl stress in seeds and growing seedlings.     

Gas exchange acclimation to elevated CO2 in upper-sunlit and lower-shaded canopy leaves in relation to nitrogen acquisition and partitioning in wheat grown in field chambers

Growth at elevated CO₂ often decreases photosynthetic capacity (acclimation) and leaf N concentrations. Lower-shaded canopy leaves may undergo both CO₂ and shade acclimation. The relationship of acclimatory responses of flag and lower-shaded canopy leaves of wheat (Triticum aestivum L.) to the N content, and possible factors affecting N gain and distribution within the plant were investigated in a wheat crop growing in field chambers set at ambient (360 μmol mol⁻¹) and elevated (700 μmol mol⁻¹) CO₂, and with two amounts of N fertilizer (none and 70 kg ha⁻¹ applied on 30 April). Photosynthesis, stomatal conductance and transpiration at a common measurement CO₂, chlorophyll and Rubisco levels of upper-sunlit (flag) and lower-shaded canopy leaves were significantly lower in elevated relative to ambient CO₂-grown plants. Both whole shoot N and leaf N per unit area decreased at elevated CO₂, and leaf N declined with canopy position. Acclimatory responses to elevated CO₂ were enhanced in N-deficient plants. With N supply, the acclimatory responses were less pronounced in lower canopy leaves relative to the flag leaf. Additional N did not increase the fraction of shoot N allocated to the flag and penultimate leaves. The decrease in photosynthetic capacity in both upper-sunlit and lower-shaded leaves in elevated CO₂ was associated with a decrease in N contents in above-ground organs and with lower N partitioning to leaves. A single relationship of N per unit leaf area to the transpiration rate accounted for a significant fraction of the variation among sun-lit and shaded leaves, growth CO₂ level and N supply. We conclude that reduced stomatal conductance and transpiration can decrease plant N, leading to acclimation to CO₂ enrichment.     

Effects of selenium supplementation on selenium status of farmed fallow deer in outdoor pens

The study investigated the effects of selenium (Se) supplementation on Se status in farmed fallow deer. Fallow deer were housed on grass pasture and adapted to consume ∼200 g of pelleted grain daily. Animals were divided into two groups. One group received pelleted grain enriched with sodium selenate for 12 weeks (Se+ group, N = 10). Se intake for the first 7 weeks was 0.18 mg/kg dry matter (DM) and 0.32 mg/kg DM for the subsequent 5 weeks. The control group was fed pelleted grain without extra Se (Se− group, N = 9, 0.06-0.08 mg/kg DM). Blood samples were collected at the beginning and the end of the experiment. After the animals were slaughtered, tissue samples were collected for analysis of Se concentrations and Se-dependent glutathione peroxidase 1 (GPx1) activity. In addition, Se-independent α-glutathione-S-transferase (α-GST) activity was analyzed in liver tissue. Se supplementation significantly increased Se levels in plasma and in tissues as follows: liver > spleen > skeletal muscle > myocardium > kidney. Se supplementation also significantly increased GPx1 activity in tissues in the following order: liver > skeletal muscle > spleen = myocardium > kidneys. However, hepatic α-GST activity did not differ between Se+ and Se− groups. As expected, Se supplementation increased blood and tissue Se concentrations and GPx1 activity, which suggests a better antioxidant status. However, the activity of α-GST, an important Se-independent antioxidant enzyme, was not altered, presumably because GPx provided an adequate antioxidant capacity even though Se intake was low.     

Morphological variations,biomass and ion accumulation of the aboveground shoots of Desmostachya bipinnata (L.) Stapf

The present study aimed to evaluate the morphological characteristics and biomass of Desmostachya bipinnata and their relation to the environmental variables in three main habitats (canal banks, railway and roadside shoulders) where it is found in Egypt. In addition, the ability of this plant is evaluated to accumulate nutrients and heavy metals in its aboveground shoots. Twenty five quadrats (1 m × 1 m per quadrat) were selected along five sites representing the different habitats of D. bipinnata for this study. The aboveground shoots displayed considerable morphological variations, differing in the different habitats. The above ground biomass, number of spikes and leaves, rachis length and diameter, leaf length, width and area, leaf sheath length, and spike length and diameter were in the order: road sides > canal banks > railway shoulders. A regression equation: biomass = (67.37 × density) + 108.2, was used to estimate the shoot biomass from the plant growth density. Metal uptake capability from soil to grass is in the order Fe > Zn > Cu > Mn, and all of them are in safe concentration ranges. These heavy metals had a transfer factor more than unity, which indicates that D. bipinnata is a powerful accumulator for heavy metals. In addition, the plant shoots exhibit high accumulation of inorganic and organic nutrients.     

Genetic parameters for physical and quality traits of mohair in South African Angora goats

The continuous evaluation and genetic improvement of fleece traits in Angora goats are of major importance to the Angora goat industry. The objective of this study was to estimate variance components and genetic parameters for both physical and quality traits of mohair in South African Angora goats. The data used for this study were collected on between 898 and 6211 kids (depending on the trait measured) born between 2000 and 2006 in 11 different Angora goat studs. Variance components and genetic parameters were estimated with the ASREML programme for fleece weight, fibre diameter, coefficient of variation of fibre diameter, standard deviation of fibre diameter, comfort factor, spinning/effective fineness and standard deviation of fibre diameter along the length of the staple. Most of these traits (excluding fleece weight) are measured using OFDA technology exclusively, and this study was the first attempt to calculate genetic parameters for these traits in South Africa. A model including the direct additive genetic effects only, were the most appropriate for estimation of all parameters. Heritability estimates were 0.24 ± 0.03 for fleece weight, 0.45 ± 0.03 for fibre diameter, 0.37 ± 0.10 for coefficient of variation of fibre diameter, 0.32 ± 0.11 for standard deviation of fibre diameter, 0.63 ± 0.10 for comfort factor, 0.61 ± 0.10 for spinning/effective fineness and 0.14 ± 0.08 for standard deviation of fibre diameter along the length of the staple. Results from this study can now be applied for the estimation of breeding values for fleece production of South African Angora goats and in incorporation into selection programs.     

Improved production of two expansin-like proteins in Pichia pastoris and investigation of their functional properties

The genes encoding expanin-like proteins from Trichoderma reesei (TrSwo1) and Bacillus subtilis (BsEXLX1) were successfully expressed in Pichia pastoris. The yields of two recombinant proteins were significantly improved by the use of PMSF (phenylmethylsulfonyl fluoride) and a commercial protease inhibitor cocktail. Under the optimum culture conditions, the highest TrSwo1/BsEXLX1 expression level reached was approximately 120/860 mg l⁻¹, which was almost 2.4/86-fold as much as the highest expression level in other host cells. Purified BsEXLX1/TrSwo1 displayed synergism in cellulose hydrolysis with endoglucanase, and the maximum amount of reducing sugars released was almost 2.0/2.5-fold as high as those in reaction mixtures without expansin-like proteins. The synergistic effect reached the maximum level when 1 mg of target protein per g of filter paper was loaded. Both proteins exhibited relatively high thermal stability at temperatures of 50, 70 and 90 °C, and retained more than 45% residual activities after 1 h of pre-incubation at 100 °C, suggesting remarkable heat tolerance. They also showed resistance to denaturation by urea and SDS. Under several enzymatic hydrolysis conditions, the synergistic activity of TrSwo1 was higher than that of BsEXLX1, indicating stronger disrupting activity of TrSwo1 on cellulose than BsEXLX1. This is the first study to report high-efficient expression and unreported properties of BsEXLX1/TrSwo1.     

正常和环割条件下不同形态氮素添加对红椎幼苗光合特性的影响

采用盆栽试验和韧皮部环割方法研究了碳水化合物供应、氮素形态及其交互作用对红椎幼苗叶片光合特性的影响。无机氮源采用硝酸铵(AN)、铵态氮(NH_4~+-N)、硝态氮(NO_3~--N),有机氮源采用尿素(Urea)、精氨酸(Arg)和甘氨酸(Gly),氮素施用量均为10g N/m~2,处理时间为10 d。研究结果表明,环割、氮素形态及其交互作用均显著影响了红椎幼苗叶片的净光合速率(Pn);单一环割处理显著降低了红椎幼苗叶片Pn、气孔导度(Gs)、胞间CO_2浓度(Ci)、蒸腾速率(Tr)、相对叶绿素含量和CO2利用效率(CUE),但显著提高了叶片水分利用效率(WUE)和气孔限制值(Ls),其叶片Pn降低主要是由气孔限制和叶绿素含量降低所导致的。正常条件下,所有氮素形态处理均显著降低了红椎幼苗叶片的Pn、Gs、Ci和Tr,但显著升高了叶片Ls和WUE,其叶片Pn降低的主要原因是供氮过高引起的叶片气孔限制。正常条件下,除Arg处理外,其他氮素形态均显著升高了红椎幼苗叶片的CUE,其中以Gly处理的促进作用最大。环割条件下,3种有机态氮素的添加均显著缓解了单一环割处理对红椎幼苗叶片Pn的抑制作用,尤其以精氨酸最为明显,供应精氨酸的叶片Pn值从单一环割处理的强烈抑制中恢复到了对照水平,而无机态氮的供应均未显著改变这种抑制。结果表明短期碳水化合物供应的阻断会显著抑制红椎幼苗叶片的光合能力,适量供应精氨酸、甘氨酸和尿素等有机态氮会有效缓解这种抑制作用,其中以精氨酸的作用最为明显。     

Phenotypic and genetic relationships between udder morphology and udder health in dairy ewes

The aim of this paper was studying the phenotypic and genetic relationships between udder morphology traits and udder health in dairy sheep. From 2000 to 2008 udder traits, somatic cell count (SCC) and clinical mastitis cases were recorded in an experimental flock consisting each year of around 900 ewes. A logistic regression was performed to evaluate the risk for a ewe of showing either a mastitis or at least 2 daily SCC records greater than 1 × 10⁶ cells/ml in one of its lactations as function of udder traits scored in 1st lactation. 1587 individual udder scores and 39,950 SCC daily records were used for the analysis. Secondly, genetic correlation between lactation mean of somatic cell score and udder traits were estimated by a REML method applied to four bi-trait animal models, using data from 2251 primiparous ewes. Logistic regression results indicated that the risk of mastitis or high SCC values during the productive life increased as the cistern height increased and the degree of udder suspension and udder depth decreased. This suggests that the appraisal of the udder is a useful tool for culling decision aimed at increasing the sanitary status of the flock. The genetic correlation between lactation SCS and udder traits were favourable for udder depth (−0.50 ± 0.12), teat placement (0.39 ± 0.011) and degree of udder suspension (−0.42 ± 0.011) and closed to zero for the degree of separation of the two halves. Thus selection for udder morphology, already implemented in some dairy sheep breeds with the aim of improving machine milkability, will lead to a favourable correlated genetic response on SCC.     

Application of genetic algorithm for determination of the effective diffusivity of andrographolide in plant materials

The effective diffusivity of natural medicinal components is an important property for a detailed pharmaceutical extraction study and a proper design of the extraction process and unit. A mass transfer mathematical model for solvent extraction of andrographolide was developed and numerically solved taking into account particle geometries, solvent concentration, mass fraction of two different geometries of plant materials, external mass transfer resistance and solid–liquid equilibrium concentration. Using inverse simulation approach with genetic algorithm, unknown four key parameters in the developed model, effective diffusivity, partition coefficient, average particle size and mass fraction of leaf particles were determined at different extraction temperatures and solvent concentrations. The simulated data through the genetic algorithm-numerical model (GA-NM) and experimental data showed a good agreement (r² > 0.97 and MSE < 0.0016) indicating that the scheme with genetic algorithm can be effectively used for determination of the effective diffusivity of andrographolide in plant materials.     

Leaf non-structural carbohydrates regulated by plant functional groups and climate: Evidences from a tropical to cold-temperate forest transect

Non-structural carbohydrates (NSCs), e.g., glucose and starch, play important roles in metabolic processes of plants and represent important functional traits in plant's adaptation to external environment. To explore the variations in leaf NSCs among species and communities at a large scale and their influencing factors, we investigated the contents of leaf NSCs among 890 plant species in nine typical forests along the north–south transect of eastern China. The results showed that the contents of leaf soluble sugars, starch, and NSCs (sugars + starch) were highly variable among different plant species on the site scale, and their mean values for the 890 plant species were 45.7 mg g⁻¹, 47.5 mg g⁻¹, and 93.2 mg g⁻¹, respectively. All three metrics varied markedly across plant functional groups in the order of trees < shrubs < herbs. Weak latitudinal patterns of leaf soluble sugars, starch, and NSCs were observed from tropical to cold-temperate forests at the levels of species and plant functional groups. The contents of leaf soluble sugars, starch, and NSCs decreased with increasing temperature and precipitation which supports the growth limitation hypothesis at a large scale. In trees, leaf soluble sugars, starch, and NSCs increased with increasing photosynthetic active radiation (PAR); and were positively correlated with specific leaf area (SLA). The spatial patterns of leaf NSCs in forests along the north–south transect of eastern China and their relationships with temperature, precipitation, PAR, and SLA illustrate an important adaptation of plant communities to environmental changes at the continental scale.     

Common gene variants in RAD51, XRCC2 and XPD are not associated with clinical outcome in soft-tissue sarcoma patients

BackgroundDNA repair mechanisms play a major role in cancer risk and progression. Germline variants in DNA repair genes may result in altered gene function and/or activity, thereby causing inter-individual differences in a patient's tumor recurrence capacity. In genes of the DNA repair pathway the gene variants RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C have been previously related to genetic predisposition and prognosis of various cancer entities. In this study we investigated the association between these polymorphisms and time to recurrence (TTR) and overall survival (OS) in soft-tissue sarcoma (STS) patients after curative surgery.MethodsTwo hundred sixty STS patients were included in this retrospective study. Germline DNA was genotyped by 5′-exonuclease (TaqMan) technology. Kaplan Meier curves and multivariate Cox proportional models were calculated for TTR and OS.ResultsA statistically significant association was observed between tumor grade and adjuvant radiotherapy and TTR and between tumor grade and OS. No association was found between RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C and TTR and OS in univariate and multivariate analysis.ConclusionOur results underline a prognostic effect of tumor grade and adjuvant radiotherapy in STS patients but indicate no association between RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C and clinical outcome in STS patients after curative surgery.     

Convergence in plant traits between species within grassland communities simplifies their monitoring

Plant trait measurement is a very powerful and promising method for assessing the effects of land use change on ecosystem behavior in grasslands, but it is very time-consuming. Hence we pose the following questions for simplifying diagnosis and monitoring: (i) are plant traits (PTs) similar between plant life forms (PLF: grasses, rosettes, upright forbs, legumes) within a plant community? (ii) is it possible to define the main plant community characteristics by measuring traits on one PLF or a limited number of dominant species?Six PTs known for their ability to characterize the capacity of species to exploit resource-rich or -poor environments and for their competitive dominance in response to disturbance (specific leaf area (SLA), leaf dry matter content (LDMC), plant height (H), C and N contents, flowering time) were measured on the species of 18 plant communities located in Central Pyrenees. The experiment combined 2 fertility levels and 3 defoliation regimes (cutting, grazing). Comparisons were made between the weighted values at community, PLF and two dominant species levels. Regression analysis shows that there were significant correlations between grasses and rosettes for 4 PTs. For H, N and C:N ratio, data for both grass and rosette PLFs were close to the bisecting line. The largest difference in the intercept was observed for LDMC. On the basis of plant traits weighted for all the species, plant communities were ranked in similar ways for SLA and H (Spearman r > 0.93; p < 0.001) and to a lesser extent for LDMC (r = 0.72; p < 0.001). Convergence in weighted plant traits for different PLFs within a plant community mean that in the studied grasslands, defoliation regime and nutrient availability act as strong filters that impose, at least at PLF level, very similar PFTs. This determines a specific local community structure and composition. An application of this result in managed grasslands is the possibility of focusing on one PLF or a limited number of species for vegetation diagnosis and monitoring.     

Trace elements in Phragmites australis growing in constructed wetlands for treatment of municipal wastewater

Biomass of Phragmites australis growing in four constructed wetlands with horizontal sub-surface flow (HF CWs) designed for treatment of municipal sewage in the Czech Republic have been analyzed for 19 trace elements. The biomass was harvested during the peak standing crop in early September and divided into stems, leaves, flowers, roots and rhizomes. Concentrations of monitored elements in both aboveground and belowground plant tissues were similar to those found in plants growing in natural stands. The highest concentrations were recorded for Al, Fe, Mn, Ba and Zn while the lowest concentrations were those of Hg, U and Cd. Concentrations decreased in the order of roots > rhizomes > leaves > stems. The root/leaf ratio averaged 70 and varied between 1.4 for molybdenum and 392 for cobalt. The belowground/aboveground concentration ratio ranged between 0.9 and 69.5 with an average value of 19. Due to average aboveground/belowground biomass ratio > 1, the belowground/aboveground standing stock ratios were lower with six elements (Ba, Zn, Se, Hg, Mo, and Mn) having this ratio < 1.