Direct comparison of assessment methods using benthic macroinvertebrates: a contribution to the EU Water Framework Directive intercalibration exercise

The aim of the intercalibration exercise presently performed by the EU is to identify and resolve significant inconsistencies between the ecological quality classifications of EU Member States and the normative definitions of the EU Water Framework Directive. Based on benthic macroinvertebrate data of two European stream types (small siliceous mountain streams and medium-sized lowland streams in Central and Western Europe) we correlated the indices of 10 river quality assessment methods (ASPT, BMWP, DSFI, German Multimetric Index, Saprobic Indices) applied in Austria, Czech Republic, Denmark, Germany, Poland, Slovak Republic, Sweden and United Kingdom. National class boundaries were compared via regression analysis. Assessment methods of the same type (Saprobic Indices, BMWP/ASPT scores) showed best correlation results (R²>0.7). The good quality status boundaries of the national methods deviated up to 25%; thus indicating the necessity to harmonize the national classification schemes. Prerequisites of the presented intercalibration approach are (1) a sufficiently large and consistent dataset representative of the respective common intercalibration types and (2) agreement on common type specific reference conditions.     

Bringing European river quality into line: an exercise to intercalibrate macro-invertebrate classification methods

The Water Framework Directive (WFD) requires intercalibration to be performed to ensure that ecological status, as defined by the boundary values of national biological assessment systems, is consistent with the definitions outlined in the WFD and comparable between Member States (MS). This article describes an intercalibration of 17 national river macro-invertebrate assessment methods from the Central and Baltic regions of Europe. We explore the hypothesis that intercalibration should be successful if ratios of the observed biota to that expected in reference condition are used to compare assessments of different national assessment systems. National boundaries expressed as ecological quality ratios (EQRs) were converted to values of a common multi-metric for the purpose of comparison. Twelve MS for the High/Good boundary and nine MS for the Good/Moderate boundary (and four MS who subsequently harmonised their boundaries) were within ±0.05 EQR units of the intercalibration boundaries and were deemed to be of comparable ecological standard. The use of a reference-based approach was deemed to be successful given that all the critical pre-requisites for intercalibration were satisfied. The boundaries derived from this intercalibration represent the first common interpretation of the ecological status of rivers based on macro-invertebrate assessment methods across Europe.     

The validation of common European class boundaries for river benthic macroinvertebrates to facilitate the intercalibration process of the Water Framework Directive

The Water Framework Directive (WFD) requires that all the water bodies in Europe be protected and enhanced to achieve Good Ecological Status by 2015. The intercalibration of the biological monitoring results of Member States has to be carried out in relation to classification tasks to guarantee a common understanding of ‘Good Ecological Status’ at a European level. An intercalibration exercise was carried out within the framework of different Geographical Intercalibration Groups (GIGs), each composed of a group of countries that share similar river types and have a discrete geographical range. By means of the intercalibration exercise, common European boundaries were proposed for river invertebrate assessment methods within each GIG. The purpose of this study was to validate the boundaries proposed for the formal intercalibration exercise. A benchmark data set was used, which comprised data, collected in different European countries that satisfied WFD requirements. The data set included a set of reference sites and provided evidence of a high degree of comparability among countries. The STAR Intercalibration Common Metric index (STAR_ICMi) was calculated for benchmark samples and was selected as the index in which national assessment boundaries were expressed. It was applied for the intercalibration exercise in two GIGs. For the STAR_ICMi, the coefficient of variation was also calculated, demonstrating a comparable variability with indices that are based on species level identification. A fixed percentile of reference samples STAR_ICMi values was selected as the boundary between High and Good status. The range from this fixed percentile to the lowest possible value was divided into four equal parts to obtain the remaining class boundaries. The resulting High/Good and Good/Moderate boundaries were compared to the boundaries proposed by GIGs and proved to be in line with those defined in the intercalibration exercise. Even if, for the intercalibration exercise, some procedures to check the Member States (MS) data sets where put into practice, it is the responsibility of each state to guarantee the WFD compliancy of their reference conditions and methods. Accordingly, the process of validation explained in this article, or similar ones, can be an important step forward and demonstrate the comparability of the actual boundaries.     

Characterization,Ecological Status and Type-specific Reference Conditions of Surface Water Bodies in Wallonia (Belgium) using Biocenotic Metrics based on Benthic Invertebrate Communities

The river types in Wallonia (Belgium) were defined according to the system B of the European Water Framework Directive (WFD) taking into account obligatory and optional factors synthesized in three criteria: ‘size’, ‘slope’ and ‘natural region’. Under the hypothesis that benthic invertebrate assemblages would be specialized according to river type, a set of 627 faunal samples originating from an 11-year sampling period was tested to characterize river types with faunal assemblages. A multivariate approach led to gather 23 river types into seven groups exhibiting similar faunal assemblages. Using biocenotic metrics based on benthic invertebrate assemblages (e.g., the French standard IBGN), type-specific reference conditions and ecological status class limits were defined for each ‘natural’ river type group. Ecological potential was defined for heavily modified and for artificial (i.e., man-made canals) types. An ‘ecological status’ evaluation strategy was therefore developed and applied in the southern – and more natural – part of Wallonia, where many reference sites were available. In the northern part of Wallonia (i.e., the ‘Loess region’) where no high quality site was available, the expert judgement took a larger part in the definition of the reference conditions and of the ecological status class limits, in addition to the calculations. Two independent distribution gradients of taxa assemblages resulted from multivariate ordination: a first ‘saprobity axis’, as the taxa-sensitivity to organic contamination was increasing from ‘very resistant’ taxa (mainly located in the ‘Loess region’) to ‘sensitive’ and ‘very sensitive’ taxa (from the river types belonging to the Condroz, the Famenne, the Arden and the Jurassic regions) and a second axis characterizing the Meuse-specific faunal assemblage, gathering exotic species and typical limnophilous taxa of large heavily modified rivers. The ecological status monitoring management system developed in this study – i.e., the definition of faunal river type groups, related reference conditions and ecological status class limits – represents a proposal to be integrated in the ecological status assessment of biological elements for the implementation of the WFD and was tested in Wallonia. For the period 2000–2002 involving 349 different sites, the element ‘benthic invertebrate fauna’ was in that way classified ‘high status’ for 31.5% of sites, ‘good status’ for 31.5% and below ‘good status’ for 37% of sites. The best ecological status (i.e., 100% ‘high’ and ‘good’ status) was found in river type ‘Arden’s xenotrophic brooks with strong slope’ and in river types 8large rivers with medium slope’. The worst status was found in river types ‘Loess brooks and rivers with medium slope’.     

The use of LCA to develop eco-label criteria for hard floor coverings on behalf of the european flower

Thorough environmental observation and a series of life cycle consideration have been performed to underpin the development of the environmental criteria of a new EU Eco-label product group following the voluntary and selective European Environmental Award Scheme based on Regulation EC 1980/ 2000. Since April 2002, the European Eco-label is available for the Hard Floor Coverings product group, subsequently also called ‘HFC’. The Eco-label translates environmental awareness on products for indoor and outdoor covering materials such as ceramic and clay tiles, concrete paving units, terrazzo, agglomerated and natural stones into a new market-based environmental policy tool. As a matter of fact, the HFC ecological criteria development has been positively concluded based on a the study of the Italian National Environment Protection Agency (ANPA, Agenzia Nazionale per la Protezione dell’Ambiente) with the technical support of Life Cycle Engineering (Turin, Italy), that had been entrusted with this task by the European Commission, DG Environment. The stakeholders involved in the ‘Ad Hoc Working Group’ activities included European Eco-label Competent Bodies, some of the most important manufacturers, consumers and environmental associations at a European level. In December 2001, after eighteen months of concerted work with all the interested parties in the European Union Eco-label Board (EUEB), the final vote of criteria by Member States enabled the publication of the EU-wide valid criteria and the elaboration of an application pack (user manual) in late March 2002.     

Assessment metrics for littoral seagrass under the European Water Framework Directive; outcomes of UK intercalibration with the Netherlands

Under the Water Framework Directive (WFD) taxonomic composition, presence of disturbance sensitive species, abundance and cover are stated attributes for monitoring the status of marine angiosperms; a biological quality element required for assessment of environmental condition. Member States (MS) are required to devise metrics for assessing these attributes to establish ecological status of water bodies. Furthermore the Directive requires intercalibration of metrics and data between MSs. Seagrass are the only truly marine angiosperms. The proposed suites of UK and Dutch metrics for assessing the specified seagrass attributes are described and comparisons made. UK and Dutch metrics are intercalibrated through testing against each nationality’s seagrass data. Strong agreement is established in the outcomes of the two suites of tools; >83%. Differences in outcomes are usually due to lack of availability of raw data. Importantly, where outcomes differ they still fall on the same side of the Good/Moderate boundary. Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users Handling editor: K. Martens An erratum to this article is available at .     

The estimation of productivity and yield of linseed (<Emphasis Type="Italic">Linum usitatissimum</Emphasis> L.) using the growth analysis

In three year field experiments (2001 – 2003) the growth, yield and productivity of 8 flax cultivars were compared. Cultivars ‘AC Linora’, ‘Flanders’, ‘Linola™ 947’, ‘Norlin’ and ‘Omega’ were obtained from Canada, ‘Barbara’ and ‘Hungarian Gold’ from Hungary and ‘Opal’ from Poland. Apart from the estimation of the yield of aboveground parts dry matter and seed yield the determinations of the primary index value of growth analysis were done and on their basis the indices LAI, LAD, RGR, CGR and HI were calculated. The obtained yield results of the examined flax cultivars show significant genotypic — environmental relationships pertaining to the dynamics of dry matter accumulation and the amount of seed yield. Meteorological conditions in the successive years significantly influenced the particular phases of growth and development of cultivars and the factor which increased the amount of dry matter was the air temperature during the period of plant emergence — budding. During the vegetative season with a large amount of rainfall the average seed yield was about 40 % lower than compared with a year of average precipitation and a warm second part of the second period of flax vegetation. Among the analyzed cultivars a stable yield in all the years was characteristic for cultivars ‘Flanders’, ‘Barbara’ and ‘AC Linora’ (that cultivar, however, during a wet year yielded at a low level). The assimilation leaf surface of the linseed quickly increased during the period from budding to flowering and the accumulation of dry matter of the aboveground parts lasted up to the green maturity. In the successive years of the experiment there were observed significant (linear or logarithmic regressions) relationship between the yield of dry matter and the indices of growth analysis. The biggest values of the CGR indicator were observed for the period from budding to flowering. The maintaining of a high CGR value after plant flowering in the year with a favourable course of climatic parameters was beneficial for a better yield of all flax cultivars. The low values of the RGR index after flowering of cultivar ‘Hungarian Gold’ and ‘Opal’ strictly corresponded to their low yield of seed and straw biomass.     

Establishing expectations for pan-European diatom based ecological status assessments

The European Union (EU) Water Framework Directive depends, for effective implementation, on Member States (MSs) agreeing to a concept of the unimpacted “reference” state, which will then provide the “expected” value in Ecological Quality Ratio (EQR) calculations. Reference assemblages of organism groups will, in turn, vary, due to geological, hydrological, climatic, physicochemical and biological factors. Member States tackle this by establishing “types” which share common characteristics. However, for the purposes of ensuring consistent application, broad transboundary types were also established within five Geographical Intercalibration Groups (GIGs, referred to here as “regions”) as part of the EU's intercalibration exercise. In this paper, we evaluate these types using river diatom assemblages and also provide reference threshold values for two common metrics used in pan-European diatom assessments. A database was assembled, representing 14 EU Member States from Ireland and Portugal in the West, to Estonia and Cyprus in the East, in order to explore biogeographical patterns in assemblages unaffected by anthropogenic pressures. Multivariate analyses were used to examine this pattern and its relationship with geographic, typological and abiotic parameters. After taxonomic harmonisation, NMDS ordination of samples indicated weak differences in assemblage composition among regions. ANOSIM analyses, in turn, indicated that MS was the best factor to group similar samples whereas alkalinity, recognised as the primary environmental variable structuring diatom communities, although significant, explained less variability in the dataset. This, we believe, reflects the importance of methodological factors other than taxonomy (e.g. counting protocol, sample season) that may be constant within a MS but which vary between MSs. When two diatom metrics, the TI and IPS, were applied to the data, differences in the distribution of the metric scores between MS were generally not statistically significant even though some differences between regions were apparent. A trend of increasing values of TI (decreasing values of IPS) was observed in the sequence: Nordic < Alpine < Mediterranean < Central-Baltic < Eastern Continental regions. Additionally, some differences were observed among types within the Mediterranean and Nordic regions, though not for other regions. The data used in this exercise provides us with a region and, in some cases, a type specific benchmark dataset against which national reference data can be compared.     

Effect of streamlining taxa lists on diatom-based indices: implications for intercalibrating ecological status

Intercalibration of ecological status class boundaries between member states is a requirement of the European Union’s Water Framework Directive. Although a preliminary intercalibration of boundaries established for phytobenthos has been performed, a number of questions remain, including the extent to which variations in taxonomic concepts used in different member states influences the position of these boundaries. In this paper, the robustness of the diatom-based metrics used for intercalibration is assessed. Whilst use of genus-level identification led to a loss of ecological information, merging representatives of closely-related taxa has little effect on these metrics. Similarly, taxa that occur only rarely or never have high relative abundances in a dataset can also be ignored without the loss of ecological information. Similar results were obtained when modern taxonomic concepts were compared with concepts in use 80 years ago. Fine scale taxonomy may play a valuable role within member states; however, our results suggest that, at a continental scale, a simplified approach to diatom taxonomy should not affect intercalibration results.     

How do 28 European Union Member States perform in agricultural greenhouse gas emissions? It depends on what we look at: Application of the multi-criteria analysis

European Union (EU) Member States have agreed to limit their greenhouse gas (GHG) emissions from sectors not covered by the EU Emissions Trading Scheme, including emissions from agricultural sector. The aggregated GHG emission rate (i.e. t CO₂ eq. from agricultural sector per country) is commonly used to measure the overall size of agriculture’s influence on climate. And indeed, since 2005, EU has managed to decrease its aggregated GHG emissions by 3.1%. However, the question is—does that mean that EU’s agriculture has become less emission intensive? This paper answers the question by providing a different perspective for the assessment and comparison of the agricultural GHG emissions in 28 EU Member States. It is done by applying three different approaches, including creation of derived indicators and application of multi-criteria analysis (TOPSIS), which is a novel approach for comparison of agricultural GHG emission mitigation performance. The results show that each EU Member State performs very differently in emission intensities. Even more, the emission intensity results show an alarming tendency of increase in most of the EU Member States, which indicates that the measured changes in aggregate agricultural GHG emission rates are misleading. Therefore, the paper suggests reconsidering the policy targets for GHG emission limits.     

A comparison of the European Water Framework Directive physical typology and RIVPACS-type models as alternative methods of establishing reference conditions for benthic macroinvertebrates

The EU Water Framework Directive requires European Union Member States to establish ‘type-specific biological reference conditions’ for streams and rivers. Types can be defined by using either a fixed typology (System-A), defined by ecoregions and categories of altitude, catchment area and geology, or by means of an alternative characterisation (System-B) that can use a variety of physical and chemical factors. Several European countries also have existing RIVPACS-type models that give site (rather than stream type) specific predictions of benthic macroinvertebrate communities. In this paper we compare the Water Framework Directive (WFD) System-A physical typology and three existing European multivariate RIVPACS-type models as alternative methods of establishing reference conditions. This work is carried out in Great Britain – using RIVPACS, Sweden – using SWEPAC_SRI and the Czech Republic – using PERLA. We found that in all three countries, all seasons and season combinations, and for all biotic indices tested, RIVPACS-type models were more effective (lower standard deviations of O/E ratios) than models based solely on the WFD System-A variables or null models (based on a single expectation for all sites). We also investigated the explanatory power of whole groups of WFD System-A variables and RIVPACS-type model variables, and the explanatory power of individual variables. We found that variables used in the RIVPACS-type models were often better correlates of macroinvertebrate community variation than the WFD System-A variables. We conclude that this is primarily because while the latter use very broad categories of map-derived variables, the former are based on continuous variables selected for their ecological significance.     

Reference conditions for phytoplankton at Danish Water Framework Directive intercalibration sites

Phytoplankton is one of the biological quality elements included in the EU Water Framework Directive (WFD). Classification of water quality according to the WFD is based on the deviation of the present conditions from reference conditions. Given the lack of data from pristine conditions, this study used approximately 100-year-old measurements of Secchi depths from Danish waters in combination with relationships between Secchi depth and chlorophyll a (as a proxy for phytoplankton biomass) obtained from recent monitoring to calculate ‘historical’ or reference chlorophyll a (Chl-a) concentrations. Historical Secchi depth data were available for 9 out of the 11 Danish WFD intercalibration sites. At eight of the sites, reference summer (May–September) Chl-a concentrations were in the range 0.7–1.2 μg l⁻¹. At one site, west of Bornholm in the western Baltic Sea, historical Secchi depth measurements date back to only the late 1950s corresponding to a calculated Chl-a concentration of 1.3 μg l⁻¹. This value cannot be considered representative of reference conditions. Guest editors: J. H. Andersen & D. J. Conley Eutrophication in Coastal Ecosystems: Selected papers from the Second International Symposium on Research and Management of Eutrophication in Coastal Ecosystems, 20–23 June 2006, Nyborg, Denmark     

Consequences of wooded shrine rituals on vegetation conservation in West Africa: a case study from the Bwaba cultural area (West Burkina Faso)

Anthropological contributions that challenge several common perceptions on sacred sites are still poorly taken into account in conservation and ecological studies. This paper aims at filling this gap and providing a better framework for biological studies. Local concepts of natural sacred sites and their ritual administration were studied and the ritual practices relating to the vegetation of these sites were analyzed in the Bwaba cultural area in West Burkina Faso. Our research shows that these ritual practices are much more diverse and fluid than might have been supposed. Protection ‘by tradition’ is thus rather different from what we call conservation. While vegetation does matter, its presence on sacred sites is not essential. In addition, under certain circumstances, sacred sites may be transferred or reproduced elsewhere. Attention is drawn to the inadequacy of ‘sacred woods’ as a category, in an ecological as well as an anthropological sense. Even if wooded shrines may contribute to biodiversity conservation as a side-effect of their religious purpose, the idea that they fundamentally are ‘endogenous’ nature conservatories must be disproved.     

Field resistance of spring barley cultivars to powdery mildew in Lithuania

During vegetative period 2004–2005 powdery mildew (Erysiphe graminis DC. f. sp. hordei Em. Marchal) field resistance of spring barley cultivars was investigated at the Lithuanian Institute of Agriculture. The spring barley genotypes tested were Lithuania-registered cultivars, cultivars from genetic resources collection, and the new cultivars used for initial breeding. In total, 23 resistance genes were present in the 84 cultivars studied. Among mono-genes only mlo and 1-B-53 showed very high resistance. Slight powdery mildew necroses (up to 3 scores) formed on cultivars possessing these genes. The maximal powdery mildew (PM) severity reached a score of 8.5 and the area under disease progress curve (AUDPC) a value of 1216.8. The cultivars ‘Primus’, ‘Astoria’, ‘Power’, ‘Harrington’ and ‘Scarlett’ were the most resistant among the non mlo cultivars. Severity of PM on ‘Primus’ reached a score of 3.5 (3.0 of PM necrosis) in average, the other cultivars were diseased from 4.5 (3.0) to 5.0 (2.0). The AUDPC values for these cultivars except ‘Scarlett’ were the lowest (85.0–145.3) among the other cultivars. The highest contrast in development of the other leaf diseases was between highly resistant and susceptible to PM cultivar groups. The fast development of PM depressed development of the other diseases 4.7 times.     

AFLP analysis of nephthytis (Syngonium podophyllum Schott) selected from somaclonal variants

This study analyzed genetic differences of 19 cultivars selected from somaclonal variants of Syngonium podophyllum Schott along with their parents as well as seven additional Syngonium species and six other aroids using amplified fragment length polymorphism (AFLP) markers generated by 12 primer sets. Among the 19 somaclonal cultivars, ‘Pink Allusion’ was selected from ‘White Butterfly’. Tissue culture of ‘Pink Allusion’ through organogenesis resulted in the development of 13 additional cultivars. Self-pollination of ‘Pink Allusion’ obtained a cultivar, ‘Regina Red Allusion’, and tissue culture propagation of ‘Regina Red Allusion’ led to the release of five other cultivars. The 12 primer sets generated a total of 1,583 scorable fragments from all accessions, of which 1,284 were polymorphic (81.9%). The percentages of polymorphic fragments within ‘White Butterfly’ and ‘Regina Red Allusion’ groups, however, were only 1.2% and 0.4%, respectively. Jaccard's similarity coefficients among somaclonal cultivars derived from ‘White Butterfly’ and ‘Regina Red Allusion’, on average, were 0.98 and 0.99, respectively. Seven out of the 15 cultivars from the ‘White Butterfly’ group and three out of six from the ‘Regina Red Allusion’ group were clearly distinguished by AFLP analysis as unique fragments were associated with respective cultivars. The unsuccessful attempt to distinguish the remaining eight cultivars from the ‘White Butterfly’ group and three from the ‘Regina Red Allusion’ group was not attributed to experimental errors or the number of primer sets used; rather it is hypothesized to be caused by DNA methylation and/or some rare mutations. This study also calls for increased genetic diversity of cultivated Syngonium as they are largely derived from somaclonal variants.     

Ochratoxin A Analysen im Blut von Arbeitnehmern in der Abfallwirtschaft

Tasks such as manual sorting of domestic wastes for recyclable goods and the deposition of various materials may result in inhalation of mycotoxin-containing aerosols. Ochratoxin A (OTA) was analyzed in blood samples from workers employed at waste handling facilities in Southern Germany to assess the potential impact of this mycotoxin, and explore its use as a biomarker of exposure to bioaerosols. Results from this analysis are reported: OTA serum levels (median values) in subgroups of workers involved in waste deposition (n=76 ‘Deponierer’) or in waste sorting (n=60 ‘Wertstoffsortierer’) were 0.36 and 0.53 ng/ml, respectively. Both groups are natives of countries within the European Community (EU). In waste sorters who were born in other European (non-EU) countries (n=72) or elsewhere (n=12 from Asia, Africa), the OTA serum levels were 0.50 and 0.37 ng/ml, respectively. In controls (n=84 office clerks at the facilities; EU citizens) the median OTA value was 0.39 ng/ml. Comparing the different groups, and previously published data on median OTA levels in the general population (0.21 ng/ml) which result from dietary (background) exposure to OTA in Germany, our data point to an additional uptake of this mycotoxin by inhalation in workers with exposure to bioaerosols. The results support the view that apart from the pathogenic and allergological relevance of microbial emissions from garbage, secondary fungal metabolites, and thus toxicological aspects, deserve further attention.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

A parentage study of closely related Ukrainian wine grape varieties using microsatellite markers

Four bred grapevine varieties released for commercial cultivation in Ukraine, namely ‘Antey Magarachskii’, ‘Rubinovyi Magaracha’, ‘Granatovyi Magaracha’ and ‘Rubin Golodrigi’, and their putative parental forms were genotyped using six microsatellite loci. Genotypes were compared with breeding records to verify genetic relationships among varieties. Results of the analysis confirmed four of six parent-offspring relationships. Results of the analysis allow to assume that genotype ‘Seyve Villard 20347’ is the direct parent of ‘Antey Magarachskii’ instead of its grandparent. The first-studied accession believed to be that of ‘Granatovyi Magaracha’ was identified as impurity. In order to verify the parentage of ‘Granatovyi Magaracha’, rest accessions of that variety and its putative parent ‘Antey Magarachskii’ were additionally genotyped at 13 nuclear loci and at three chloroplast loci. The parent-offspring relationship was confirmed, as all ‘Granatovyi Magaracha’ accessions had a common allele with the parent variety ‘Antey Magarachskii’ at each locus and the same chlorotype A. Different ‘Granatovyi Magaracha’ accessions could have been obtained via vegetative propagation of two seedlings which arose from one crossing.     

Selection of Highly Informative Microsatellite Markers to Identify Pollen Donors in ‘Hass’ Avocado Orchards

‘Hass’ is the most popular avocado (Persea americana Mill.) cultivar in the world. It has been characterized as a crop requiring cross-pollination. However, the potential extent of self-pollination and the most effective pollen donors (best cross-pollinizing cultivars) have not been determined. In this study, 56 markers were screened against ‘Hass’ and nine commonly used pollinizing cultivars grown in southern California: ‘Bacon,’ ‘Ettinger,’ ‘Fuerte,’ ‘Harvest,’ ‘Lamb Hass,’ ‘Marvel,’ ‘Nobel,’ ‘Sir Prize,’ and ‘Zutano.’ Seventeen microsatellite, i.e., simple sequence repeat (SSR) markers, were found to be very promising for paternity analysis. Four highly informative SSR markers were selected to accurately and unequivocally identify pollen parents of ‘Hass’ fruit from an orchard interplanted with these pollinizing cultivars. From 2003 to 2006, 7,984 ‘Hass’ fruit were analyzed for their paternity. Overall, the pollen parents of 99.55% of the analyzed fruit could be unequivocally identified with a single multiplex polymerase chain reaction (PCR). Only 36 fruits (<0.45%) required a second PCR reaction to reach unequivocal identification of the pollen parents.     

Response of antioxidant activity to excess copper in two cultivars of <Emphasis Type="Italic">Brassica campestris</Emphasis> ssp. <Emphasis Type="Italic">chinensis</Emphasis> Makino

Changes in ascorbic acid content and antioxidant enzyme activities were investigated in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) leaves of ‘Wutacai’ and ‘Erqing’ exposed to excess copper (Cu). Cu treatment reduced the fresh weight of shoot and root by 57% and 46% in ‘Wutacai’, and 60 and 54% in ‘Erqing’, respectively. The accumulation of copper in leaves was higher in ‘Wutacai’ than that in ‘Erqing’. Compared to the control, ascorbic acid (AsA) contents were significantly decreased after copper treatment in both cultivars, while they were higher in ‘Wutacai’ than in ‘Erqing’, which may explain the higher copper-tolerance of ‘Wutacai’ with higher copper accumulation. The higher AsA contents of ‘Wutacai’ resulted from their lower activities of degrading enzymes, such as ascorbate oxydase (AAO) and ascorbate peroxidase (APX), as well as the increasing activity of dehydroascorbate reductase (DHAR) after copper treatment compared with ‘Erqing’. Copper stimulated superoxide dismutase (SOD) activity in both cultivars, but for catalase (CAT), there was little difference between both cultivars. Peroxidases (POD) activity was decreased after copper treatment in ‘Erqing’, while in ‘Wutacai’, it was significantly increased at 14 days, and POD activity was higher in ‘Wutacai’ than that in ‘Erqing’ at 21 and 28 days. Therefore, the induced increasing activity of POD in ‘Wutacai’ also played an important role in its copper tolerance.