Know your enemy: Application of ATR-FTIR spectroscopy to invasive species control.

Extreme weather and globalisation leave our climate vulnerable to invasion by alien species, which have negative impacts on the economy, biodiversity, and ecosystem services. Rapid and accurate identification is key to the control of invasive alien species. However, visually similar species hinder conservation efforts, for example hybrids within the Japanese Knotweed complex.We applied the novel method of ATR-FTIR spectroscopy combined with chemometrics (mathematics applied to chemical data) to historic herbarium samples, taking 1580 spectra in total. Samples included five species from within the interbreeding Japanese Knotweed complex (including three varieties of Japanese Knotweed), six hybrids and five species from the wider Polygonaceae family. Spectral data from herbarium specimens were analysed with several chemometric techniques: support vector machines (SVM) for differentiation between plant types, supported by ploidy levels; principal component analysis loadings and spectral biomarkers to explore differences between the highly invasive Reynoutria japonica var. japonica and its non-invasive counterpart Reynoutria japonica var. compacta; hierarchical cluster analysis (HCA) to investigate the relationship between plants within the Polygonaceae family, of the Fallopia, Reynoutria, Rumex and Fagopyrum genera.ATR-FTIR spectroscopy coupled with SVM successfully differentiated between plant type, leaf surface and geographical location, even in herbarium samples of varying age. Differences between Reynoutria japonica var. japonica and Reynoutria japonica var. compacta included the presence of two polysaccharides, glucomannan and xyloglucan, at higher concentrations in Reynoutria japonica var. japonica than Reynoutria japonica var. compacta. HCA analysis indicated that potential genetic linkages are sometimes masked by environmental factors; an effect that can either be reduced or encouraged by altering the input parameters. Entering the absorbance values for key wavenumbers, previously highlighted by principal component analysis loadings, favours linkages in the resultant HCA dendrogram corresponding to expected genetic relationships, whilst environmental associations are encouraged using the spectral fingerprint region.The ability to distinguish between closely related interbreeding species and hybrids, based on their spectral signature, raises the possibility of using this approach for determining the origin of Japanese knotweed infestations in legal cases where the clonal nature of plants currently makes this difficult and for the targeted control of species and hybrids. These techniques also provide a new method for supporting biogeographical studies.

Seed discontinuous hydration does not benefit germination, but improves drought tolerance of Triplaris gardneriana seedlings

The discontinuous seed hydration enables the acquisition of tolerance to environmental stresses, causing a stress imprint. It may modify metabolic patterns and lead to improved stress responses. This study aims to evaluate the effects of discontinuous hydration on germination and on seedling growth of Triplaris gardneriana Wedd. under intermittent drought. The seeds have gone through cycles (0, 1, 2 and 3) of hydration and dehydration (HD). The seedlings produced were subjected to water deficit (daily watering and intervals of seven and fourteen days between watering). Seed germinability parameters and, relative growth rate (RGR) of seedling, leaf area, dry matter yield and leaf relative water content (RWC) were evaluated. The HD cycles did not benefit germination, but two HD cycles induced a better biomass accumulation and increased leaf area in seedlings under moderate water deficit, while three HD cycles promoted an increase in RGR and influenced the RWC values. Severe stress affects seedling growth, but subjection to HD cycles minimizes the deleterious effects of drought, suggesting discontinuous hydration acts leading stress imprint in plants.

Few effects of invasive plants Reynoutria japonica, Rudbeckia laciniata and Solidago gigantea on soil physical and chemical properties.

Biological invasions are an important problem of human-induced changes at a global scale. Invasive plants can modify soil nutrient pools and element cycling, creating feedbacks that potentially stabilize current or accelerate further invasion, and prevent re-establishment of native species. The aim of this study was to compare the effects of Reynoutria japonica, Rudbeckia laciniata and Solidago gigantea, invading non-forest areas located within or outside river valleys, on soil physical and chemical parameters, including soil moisture, element concentrations, organic matter content and pH. Additionally, invasion effects on plant species number and total plant cover were assessed. The concentrations of elements in shoots and roots of invasive and native plants were also measured. Split-plot ANOVA revealed that the invasions significantly reduced plant species number, but did not affect most soil physical and chemical properties. The invasions decreased total P concentration and increased N-NO3 concentration in soil in comparison to native vegetation, though the latter only in the case of R. japonica. The influence of invasion on soil properties did not depend on location (within- or outside valleys). The lack of invasion effects on most soil properties does not necessarily imply the lack of influence of invasive plants, but may suggest that the direction of the changes varies among replicate sites and there are no general patterns of invasion-induced alterations for these parameters. Tissue element concentrations, with the exception of Mg, did not differ between invasive and native plants, and were not related to soil element concentrations.

Different responses of alpine plants to nitrogen addition: effects on plant-plant interactions.

The different responses of plant species to resource stress are keys to understand the dynamics of plant community in a changing environment. To test the hypothesis that nitrogen (N) increase would benefit N competitive species, rather than N stress-tolerant species, to compete with neighbours, we conducted an experiment with neighbour removal, N addition and soil moisture as treatments in an alpine grassland on the southeastern Tibetan Plateau. Both growths and competitive-response abilities (CRA, the ability to tolerate the inhibitory effects of neighbors) of Kobresia macrantha, Polygonum viviparum and Potentilla anserine in wet site were facilitated by N addition, conversely, both growths and CRA of Taraxacum mongolicum and Ligularia virgaurea were suppressed by N addition, indicating that the responses of CRA of target species under N addition were consistent with the N utilization strategies of them. Moreover, the facilitative effects of N addition on competitive-response abilities of Kobresia macrantha and Polygonum viviparum were not found at the dry site, illustrating that soil moisture can alter the changes of neighbour effects caused by N addition. Life strategy of dominant species in plant community on the undisturbed southeastern Tibetan Plateau may shift from N stress-tolerant to N competitive, if the N increases continuously.

Post-Fire Recovery in Coastal Sage Scrub: Seed Rain and Community Trajectory.

Disturbance is a primary mechanism structuring ecological communities. However, human activity has the potential to alter the frequency and intensity of natural disturbance regimes, with subsequent effects on ecosystem processes. In Southern California, human development has led to increased fire frequency close to urban areas that can form a positive feedback with invasive plant spread. Understanding how abiotic and biotic factors structure post-fire plant communities is a critical component of post-fire management and restoration. In this study we considered a variety of mechanisms affecting post-fire vegetation recovery in Riversidean sage scrub. Comparing recently burned plots to unburned plots, we found that burning significantly reduced species richness and percent cover of exotic vegetation the first two years following a 100-hectare wildfire. Seed rain was higher in burned plots, with more native forb seeds, while unburned plots had more exotic grass seeds. Moreover, there were significant correlations between seed rain composition and plant cover composition the year prior and the year after. Collectively, this case study suggests that fire can alter community composition, but there was not compelling evidence of a vegetation-type conversion. Instead, the changes in the community composition were temporary and convergence in community composition was apparent within two years post-fire.

[Textual research for Tibetan medicine Qumazi].

Qumazi is a commonly used Tibetan medicine. With a long history, it can be found in the Four Medical Tantras written by gYu-thog rNying-ma Yon-tan mGon-po since the 8th century AD. Qumazi grows in mudflats and fields, including species growing in highlands, lowlands, mountains and farmlands. According to records in Crystal Beads Materia Medica, it features green sword-shaped leaves, thin stems with red veins, inserted panicles, white chicken-like flowers and copper needle row-like roots. However, there are many inconsistent morphological descriptions for Qumazi plants in many Chinese versions of Tibetan medicine books. In this article, after studying ancient and modern Tibetan medicine books, consulting experts and conducting surveys, the authors confirmed that Qumazi belongs to Rheum of Polygonaceae, including Rheum nobile Hook. f. et. Thoms, R. globulosum Gage, R. alexandrae Hook. f. et. Thoms, R. pumilum Maxim and R. delavayi Franch. In some regions, Qumazi is substituted by R. spiciforme Royle and R. przewalskyi Losinsk. After the Chinese version of Qinghai-Tibet Plateau Drug Illustrations was published in 1972, Qumazi has been miswritten as P. sibiricum Laxm in many Chinese versions of Tibetan medicine books, perhaps because P. sibiricum Laxm has many similar features with Qumazi as described in Crystal Beads Materia Medica and then is mistranslated from Tibetan to Chinese versions. According to records, Qumazi can reduce edema and is mainly applied to treat the minamata disease in clinic.

Fitness and field performance of a mass-reared biological control agent, Rhinoncomimus latipes (Coleoptera: Curculionidae).

Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae), a biological control agent of mile-a-minute weed, Persicaria perfoliata (L.) H. Gross, has been mass reared with no infusion of new genetic material for 8-9 yr (at least 24-36 generations), while insects from the same genetic stock have been subject to field conditions in North America for that same period of time. Our main objective was to compare the laboratory population with the field population (and in 1 yr with a Chinese field population) to determine whether genetic changes had occurred, especially ones that may reduce the effectiveness of the laboratory population when released in the field. The laboratory insects laid more eggs and had reduced survival compared with field weevils in several comparisons, and had reduced responsiveness to cues that induce reproductive diapause. Exposure to older plants had the greatest effect on induction of reproductive diapause in both laboratory and field weevils, with effects of daylength and temperature less pronounced. At least a portion of the laboratory weevil population overwintered successfully. Results suggest that it is not necessary to add wild-type genetic material to the rearing colony at this time.

Cytomorphological investigations in Oxyria digyna Hill. from the Kashmir Himalaya, India.

In the present paper, detailed cytomorphological investigations in Oxyria digyna Hill. from Kashmir Himalaya-India have been reported for the first time. All the of 14 investigated populations of O. digyna are diploid based on x = 7. Out of these in two populations 0-2B chromosomes have been recorded for the first time while 6 populations differed significantly in their meiotic characteristics. Meiotic abnormalities during male meiosis observed include inter PMC chromatin transfer (cytomixis). Non-synchronous disjunction of some bivalents, laggards and bridges at anaphases and telophases. Consequent to these meiotic anomalies, microsporogenesis in meiocytes is abnormal resulting in to dyads, triads and polyads with or without micronuclei. The overall effect is seen in reduced pollen fertility. Unreduced pollen grains were observed in some populations, which differed significantly in their size compared to the normal (reduced) pollen grains. It is observed that a smaller frequency of pollen grains differed morphologically in Aharbal and Yosmarg populations. The remaining eight populations showed regular meiotic course, normal microsporogenesis and high percentage of pollen fertility (95.09-99.09%).

Branching the risks: architectural plasticity and bet-hedging in Mediterranean annuals.

It has been suggested that architectural plasticity in shoot size and number allows plants to manage environmental risks. Simpler structures require shorter development times and fewer resources, which secure minimal fitness even under risky and unfavourable conditions. Here we tested the hypothesis that the magnitude of such architectural plasticity depends on the species' developmental strategy. Specifically, species with late reproduction were expected to express the highest levels of architectural plasticity in response to environmental cues predicting high probability of abrupt deterioration in growth conditions. This hypothesis was tested by comparing Mediterranean and semi-arid populations of three species, which differed in growth strategy: Trifolium purpureum, a determinate and late flowerer, and Emex spinosa and Hippocrepis unisiliquosa that flower indeterminately throughout the season. All plants were exposed to varying levels of water availability and competition, but only T. purpureum displayed plastic architectural responsiveness to the experimental manipulations. In contrast, the early and extended step-by-step flowering of both E. spinosa and H. unisiliquosa reflected a relatively deterministic bet-hedging reproductive schedule, whereby minimum fitness is secured even under adverse conditions. These two opposing strategies gave contrasting results, with E. spinosa and H. unisiliquosa displaying reduced efficiency under favourable conditions under which T. purpureum had the highest reproductive efficiency. The evolutionary interplay between deterministic risk-averse and plastic risk-prone growth strategies might reflect contrasts in the probability and severity of environmental risks, and the costs of missed opportunities.

[Study on origin and species of Heshouwu].

Recently the safety of Heshouwu become a focus, but the reasons of its hepotoxicity are confused. On the basis of literature research, some findings on species and usage custom maybe supply some clues to explain the reasons of its hepotoxicity. Heshouwu had red Heshouwu (male) and white Heshouwu (female) in ancient literature, and traditional usage was use of the male and female together. The Latin name of red Heshouwu is Fallopia multiflora, and that of the white one is F. multiflora var. multiflora.

[Studies on adventitious root induction in vitro and suspension culture of Polygonum multiflorum].

To achieve sustainable resources use of Polygonum multiflorum, adventitious roots were efficiently induced and cultured by suspension culture. In order to obtain optimal medium for induction adventitious roots from the young stems of P. multiflorum, MS medium was optimized by supplementing with different concentrations of sucrose and plant growth substances. The optimal medium for suspension culture of adventitious roots was determined by orthogonal design. The adventitious roots with suspension culture were subcultured, and the growth curve was also determined. Furthermore, the effective compound in adventitious roots was detected. The result indicated that the optimal medium for efficient induction of adventitious roots was MS medium containing 4% w/v sucrose, supplemented with 2.0 mg x L(-1) NAA, and 0.2 mg x L(-1) 6-BA. The optimal medium for suspension culture of adventitious roots was MS medium containing 3% sucrose, supplemented with 2.0 mg x L(-1) NAA, and 0.2 mg x L(-1) ABT-7.2,3,5,4'-tetrahydroxyl-diphenyl-ethylene-2-O-beta-D-glucoside was detected in adventitious roots, which was effective compound in medicinal material of P. multiflorum. In conclusion, the experiment achieved efficient induction and suspension culture of adventitious roots of P. multiflorum, and laid a foundation for the research on the sustainable use of traditional Chinese medicine resources.

[Effects of stumping on Calligonum mongolicum shelterbelt growth and soil moisture and salt distribution along Tarim Desert Highway, Xinjiang of Northwest China].

In order to ensure the stability and sustainability of the Calligonum mongolicum shelterbelt along Tarim Desert Highway, the aged C. mongolicum was stumped to investigate its growth and soil moisture and salt distribution. After stumping twice, C. mongolicum grew rapidly in its height, crown width, maximum basal diameter, and sprout number. Three years after stumping, the average height of the sprouts exceeded the control (no stumping), and the crown width and maximum basal diameter was 92.0% and 73.0% of the control, respectively. The fresh mass of the branches and assimilating branches, their dry mass, and the total fresh mass and dry mass of the aboveground parts reached 80.0%, 115.0%, 80.0%, 116.0%, 93.5%, and 88.0% of the control, respectively. Four years after stumping, the aboveground biomass surpassed the control. Comparing with the control, stumping increased the soil moisture content significantly and decreased the soil salt concentration. It was suggested that, to stump the aged C. mongolicum repeatedly could increase the soil moisture content and decrease the soil salt concentration in root zone, and effectively promote the rejuvenation and renewing of C. mongolicum.

[Effects of thinning on Calligonum arborescens growth and soil water-salt distribution in Tarim Desert Highway shelterbelt, Xinjiang of Northwest China].

In order to understand the effects of thinning on the growth of Calligonum arborescens and the soil water-salt distribution in Tarim Desert Highway shelterbelt, a thinning experiment was conducted on an aged and declined C. arborescens woodland in a demonstration section of the shelterbelt, with the growth of C. arborescens and the soil water-salt distribution monitored. Thinning had no effects on the phenophase of C. arborescens, but after thinning, the growth of the current year plant height, crown width, ground diameter, and new branch length of reserved trees was larger than that of the control, and the increment was in the order of planting space 2 mx 1 m > 1 m x 1 m > the control, with significant differences among the treatments. The assimilation branch surface area in treatments 2 mx 1 m and 1 m x 1 m were 5.97 m2 and 5.22 m2 per plant, respectively, being significantly larger than the control (3.1 m2 per plant). The soil moisture content in 0-160 cm layer was significantly higher in treatments 2 m x 1 m and 1 mx 1 m than in the control, and increased obviously with thinning intensity. The soil salt content was in the order of control > planting space 1 m x 1 m > 2 m x 1 m, and the differences among the treatments were significant. It was suggested that the best reserved plant density after thinning was planting space 2 m x 1 m.

Insect herbivores of Coccoloba cereifera do not select asymmetric plants.

Fluctuating asymmetry (FA) represents small, random variations from the symmetric bilateral pattern, and it is a frequently used measurement of plant and animal stresses. Some studies have shown a relationship between FA and herbivory, suggesting that FA might be a reliable indicator of plant quality and plant susceptibility to herbivore attack. In this study, we investigated the relationship between leaf FA of Coccoloba cereifera Schwacke (Polygonaceae) and the pattern of attack by the scale insect Abgrallaspis cyanophylly Signoret (Hemiptera: Diaspididae). Thirty individuals of C. cereifera were marked and followed during 2007 in southeastern Brazil, and all leaves of three shoots per plant were sampled, numbered, and categorized as young, mature, or senescent. We measured right and left widths of all leaves after digitizing the images to determine levels of FA for each leaf sampled per plant. Individuals of A. cyanophylli were counted using a stereoscope in the laboratory to determine infestation levels. Leaves of C. cereifera exhibited true patterns of FA, as shown by the normal distribution of asymmetry values. We observed high variation in attack rates by A. cyanophylly among C. cereifera individuals, with 43.3% of plants with no insects, whereas others exhibited up to 23,000 insects. No statistically significant relationship was observed between variation in FA and variation in A. cyanophylli among plants. These results suggest that FA cannot be used as an indicator of plant quality and susceptibility to herbivore attack but suggest that herbivores themselves might act as plant stressors.

The correlation between bioactive components of Fallopia multiflora root and environmental factors.

Fallopia multiflora (Thunb.) Harald, a traditional Chinese medicinal plant, is used in treating dizziness. In this study, the samples of F. multiflora from ten different locations were collected, and five bioactive components (2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-glucoside, emodin, emodin-8-O-beta-D-glucoside, physcion and physcion-8-O-beta-D-glucoside) were quantified by high performance liquid chromatography. The correlations between 17 environmental factors and 5 bioactive components were analyzed. The results showed that the highest contents of bioactive components were in samples from Deqing, and the lowest in samples from Tianyang, which indicated that the quality of F. multiflora grown in Deqing was superior, while that grown in Tianyang was inferior. Emodin content was negatively correlated with the average temperature in January (p < 0.01) and the accumulated temperature (p < 0.01). Physician content was also negatively correlated with the average temperature in January (P < 0.01), the accumulated temperature (p < 0.05) and the organic matter (p < 0.05). However, emodin was positively correlated with the soil available K (p < 0.05) and Zn (p < 0.01). The results of stepwise regression showed that the accumulated temperature was the main factor influencing the contents of emodin and physcion. However, none of the environmental factors had significant correlation with 2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-glucoside, emodin-8- O-beta-D-glucoside and physcion-8-O-beta-D-glucoside. In conclusion, some environmental factors have significant influence on the content of dissociated anthraquinones, while some have no influence on that of combined anthraquinones.

Fructification phenology as an important tool in the recovery of iron mining areas in Minas Gerais, Brazil.

'Canga' is a name given to the ferruginous rocky fields that can be found in the 'Quadrilátero Ferrífero' of Minas Gerais, Brazil. The endemism and species richness make them areas of special biological importance, regarded as high-priority for conservation. Nevertheless, they are being threatened by intense mining activity. Aiming to understand more about this flora, this study was performed in order to determine the maturation or dispersal period of the fruits of four Canga species, Alibertia vaccinioides K.Schum. (Rubiaceae), Coccoloba acrostichoides Cham. (Polygonaceae), Miconia sellowiana Naudin (Melastomataceae), and one probable new species of Calyptranthes Sw. (Myrtaceae). Although fruit maturation or dispersal tended to occur at the end of the dry season, some asynchrony was observed in these species, with food sources being available during most of the year. This shows that these species have the potential to attract animals the whole year round, and planting them for the recovery of iron mining areas may increase the community's self-regeneration capacity, leading to a more successful restoration process.

Fructification phenology as an important tool in the recovery of iron mining areas in Minas Gerais, Brazil / Fenologia da frutificação como importante ferramenta na recuperação de áreas de mineração de ferro em Minas Gerais, Brasil

"Canga" is a name given to the ferruginous rocky fields that can be found in the "Quadrilátero Ferrífero" of Minas Gerais, Brazil. The endemism and species richness make them areas of special biological importance, regarded as high-priority for conservation. Nevertheless, they are being threatened by intense mining activity. Aiming to understand more about this flora, this study was performed in order to determine the maturation or dispersal period of the fruits of four Canga species, Alibertia vaccinioides K.Schum. (Rubiaceae), Coccoloba acrostichoides Cham. (Polygonaceae), Miconia sellowiana Naudin (Melastomataceae), and one probable new species of Calyptranthes Sw. (Myrtaceae). Although fruit maturation or dispersal tended to occur at the end of the dry season, some asynchrony was observed in these species, with food sources being available during most of the year. This shows that these species have the potential to attract animals the whole year round, and planting them for the recovery of iron mining areas may increase the community's self-regeneration capacity, leading to a more successful restoration process.

Canga é um nome dado para os campos rupestres ferruginosos encontrados no Quadrilátero Ferrífero de Minas Gerais. O endemismo e riqueza de espécies os tornam uma área de importância biológica especial, considerada prioritária para conservação. Além disso, tem sido submetida à intensa atividade mineradora. Este estudo objetivou determinar as épocas de maturação/dispersão de frutos de quatro espécies de ocorrência na canga, Alibertia vaccinioides K. Schum. (Rubiaceae), Coccoloba acrostichoides Cham. (Polygonaceae), Miconia sellowiana Naudin (Melastomataceae) e de uma provável espécie nova de Calyptranthes Sw. (Myrtaceae). Apesar da maturação/dispersão dos frutos ter apresentado uma tendência de ocorrer no final da estação seca, foi constatada uma assincronia do evento entre essas espécies, com disponibilidade de alimento aos animais frugívoros ao longo de grande parte do ano. O plantio dessas espécies para recuperação de áreas ferruginosas similares degradadas pela mineração poderá atrair fauna durante todas as estações, aumentando o potencial de autorregeneração da comunidade e o consequente sucesso no processo de restauração.

Large clones on cliff faces: expanding by rhizomes through crevices.

BACKGROUND AND AIMS: Large clones of rhizomatous plants are found in many habitats, but little is known about whether such clones also occur on cliff faces where environmental conditions are extremely harsh and heterogeneous. METHODS: Using molecular (intersimple sequence repeat, ISSR) markers, the genotypic composition of a cliff-face population of Oxyria sinensis in Sichuan, China, was investigated. KEY RESULTS: The 98 O. sinensis ramets sampled belonged to 12 different genotypes (clones). The three most frequent clones were represented with 45, 22 and 12 ramets, respectively; the remaining nine were represented with only one to five ramets. The three largest clones spanned at least 2.7 m in the vertical direction and 4.6-6.9 m in the horizontal direction on the cliff face. CONCLUSIONS: On the cliff face, large clones of O. sinensis are formed by rhizomes growing along the crevices. Expansion by rhizomes may help O. sinensis to exploit the patchy resources and support establishment and growth of new ramets. Moreover, rooted ramets connected by rhizomes may effectively reduce the susceptibility of O. sinensis to rock fall and erosion and thus greatly improve the chances for long-term survival. The multi-clone structure indicates that sexual reproduction is also important for the long-term persistence of O. sinensis populations on cliffs.

A cortical band of gelatinous fibers causes the coiling of redvine tendrils: a model based upon cytochemical and immunocytochemical studies.

A cortical band of fiber cells originate de novo in tendrils of redvine [Brunnichia ovata (Walt.) Shiners] when these convert from straight, supple young filaments to stiffened coiled structures in response to touch stimulation. We have analyzed the cell walls of these fibers by in situ localization techniques to determine their composition and possible role(s) in the coiling process. The fiber cell wall consists of a primary cell wall and two lignified secondary wall layers (S(1) and S(2)) and a less lignified gelatinous (G) layer proximal to the plasmalemma. Compositionally, the fibers are sharply distinct from surrounding parenchyma as determined by antibody and affinity probes. The fiber cell walls are highly enriched in cellulose, callose and xylan but contain no homogalacturonan, either esterified or de-esterified. Rhamnogalacturonan-I (RG-I) epitopes are not detected in the S layers, although they are in both the gelatinous layer and primary wall, indicating a further restriction of RG-I in the fiber cells. Lignin is concentrated in the secondary wall layers of the fiber and the compound middle lamellae/primary cell wall but is absent from the gelatinous layer. Our observations indicate that these fibers play a central role in tendril function, not only in stabilizing its final shape after coiling but also generating the tensile strength responsible for the coiling. This theory is further substantiated by the absence of gelatinous layers in the fibers of the rare tendrils that fail to coil. These data indicate that gelatinous-type fibers are responsible for the coiling of redvine tendrils and a number of other tendrils and vines.

Performance of potential non-crop or wild species under OECD 208 testing guideline study conditions for terrestrial non-target plants.

The inclusion of 52 potential non-crop or wild species in new OECD guidelines for terrestrial non-target plant (TNTP) testing led to a ring test conducted by four laboratories experienced in regulatory testing. Species selected had shown potential to meet validity criteria of emergence for TNTP studies in a previous evaluation of the 52 species. OECD 208 guideline conditions were applied, with and without seed pretreatments recommended to enhance germination. These species were Abutilon theophrasti (L.) Medic., Avena fatua L., Fallopia convolvulus (L.) Adans., Galium aparine L., Ipomoea hederacea (L.) Jacq. and Veronica persica Poir. Only I. hederacea met the validity criterion of 70% emergence in all laboratories and showed a low variability in biomass. Of the other species, none led to 70% emergence in all four laboratories. The recommended pretreatments did not have a major impact on emergence. Biomass was also investigated with A. theophrasti, A. fatua, Centaurea cyanus L., I. hederacea and Rumex crispus L. Variability of biomass, a key parameter in TNTP regulatory studies, exceeded normal biomass variability of crop species used for TNTP studies. The addition of a thin layer of quartz sand to the soil surface resulted in improved emergence of C. cyanus, G. aparine and V. persica; however, such a procedure, while routine in screening studies to improve germination, is a deviation from the TNTP guidelines. These initial studies indicate that some species could meet the emergence criteria for TNTP testing. However, there is a need for further studies on seed source, seed quality and conditions for uniform emergence before their use in routine regulatory testing.