Time-invariant differences between plant individuals in interactions with arthropods correlate with intraspecific variation in plant phenology, morphology and floral scent.

The basic units of ecological and evolutionary processes are individuals. Network studies aiming to infer mechanisms from complex systems, however, usually focus on interactions between species, not individuals. Accordingly, the structure and underlying mechanisms of individual-based interaction networks remain largely unknown. In a common garden, we recorded all interactions on flowers and leaves of 97 Sinapis arvensis individuals from seedling stage to fruit set and related interindividual differences in interactions to the plant individuals' phenotypes. The plant individuals significantly differed in their quantitative and qualitative interactions with arthropods on flowers and leaves. These differences remained stable over the entire season and thus were time-invariant. Variation in interacting arthropod communities could be explained by a pronounced intraspecific variability in flowering phenology, morphology and flower scent, and translated into variation in reproductive success. Interestingly, plant individuals with a similar composition of flower visitors were also visited by a similar assemblage of interaction partners at leaves. Our results show that the nonuniformity of plant species has pronounced effects in community ecology, potentially with implications for the persistence of communities and populations, and their ability to withstand environmental fluctuations.

[Micromorphological comparative identification between several Chinese herbal medicines and their counterfeits].

OBJECTIVE: To identify comparatively several commercial Chinese herbal medicines and their counterfeits. METHOD: The micromorphological characters were identified. The shape, surface, section and other characters of the medicinal materials were identified by using anatomical lens and scanning apparatus. Pictures were taken and saved. RESULT: Main micromorphological differences between several Chinese herbal medicine including Lonicera macranthoides, L. similis, Cuminum cyminum, Plantago asiatica, Cuscuta chinensis, Sinapis alba, Salvia miltiorrhiza and their counterfeits were identified. CONCLUSION: The reference for the authenticity identification of Chinese herbal medicine and helpful experiences for the research of the same subject were provided.

Comparison of the Phytotoxkit microbiotest and chemical variables for toxicity evaluation of sediments.

The main objective of the research was to evaluate the suitability of the Phytotoxkit microbiotest as a tool for hazard assessment of sediments. The concentrations of oil derivatives, polycyclic aromatic hydrocarbons (PAHs), and heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined in sediment samples collected from the urban canal in Opole (Poland), in order to obtain a general insight of the level of sediment contamination. Phytotoxicity of sediments was estimated on the basis of seed germination and root elongation measurements, combined into an overall germination index (GI). The results revealed spatial and vertical differentiation in sediment contamination. A good correlation was obtained between organic matter content and the concentrations of particular sediment pollutants. Values of correlation coefficients at P < 0.05 ranged from 0.3246 for oil derivatives to 0.8929 for PAHs. Phytotoxicity tests, carried out on the monocotyl Sorghum saccharatum and the dicotyls Sinapis alba and Lepidium sativum, showed different responses of the three plant species to sediment samples ranging from growth inhibition to growth stimulation. The GI values revealed the following increasing order of plant sensitivity to contaminated sediments: L. sativum < S. alba < S. saccharatum. The study demonstrated that the Phytotoxkit microbiotest was effective in identifying toxic samples. However, sediment organic matter content and grain-size distribution had a significant impact on both sediment contamination and higher plantresponses to contaminated samples. The implication of these findings are discussed.