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Insect herbivory imposes stress on host plants. This stress may cause an increase in leaf fluctuating asymmetry (FA), which is defined as the magnitude of the random deviations from a symmetrical leaf shape. We tested the hypothesis that differences in leaf FA among individual shoots of downy birch, Betula pubescens, are at least partly explained by local damage caused by insects in the previous year. Unexpectedly, we found that in the year following the damage imposed by miners, leafrollers and defoliators, damaged birch shoots produced leaves with lower FAs compared to shoots from the same tree that had not been damaged by insects. This effect was consistent among the different groups of insects investigated, but intra-species comparisons showed that statistical significance was reached only in shoots that had been damaged by the birch leaf roller, Deporaus betulae. The detected decrease in leaf FA in the year following the damage agrees with the increases in shoot performance and in antiherbivore defence. The present results indicate that within-plant variation in leaf FA may have its origin in previous-year damage by insects, and that FA may influence the current-year’s distribution of herbivory.

The eco-evolutionary theory of developmental instability predicts that small, non-directional deviations from perfect symmetry in morphological traits (termed fluctuating asymmetry, FA) emerge when an individual is unable to buffer environmental or genetic stress during its development. Consequently, FA is widely used as an index of stress. The goal of the present study was to experimentally test a seemingly trivial prediction derived from the theory of developmental instability—and from previous observational studies—that significant growth retardation (which indicates stress) in plants is accompanied by an increase in FA of their leaves. We induced stress, evidenced by a significant decrease in biomass relative to control, in cucumber (Cucumis sativus), sweet pepper (Capsicum annuum), and common bean (Phaseolus vulgaris) by applying water solutions of copper and nickel to the soil in which plants were grown. Repeated blind measurements of plant leaves revealed that leaf FA did not differ between stressed and control plants. This finding, once again, demonstrated that FA cannot be seen as a universal indicator of environmental stress. We recommend that the use of FA as a stress index is discontinued until the scope of the developmental instability theory is clarified and its applicability limits are identified.

Abstract-The purpose of this study was to quantify the shape and compare fluctuating asymmetry (FA), as a random deviations from perfect bilateral symmetry of flowers of five species of plant. The shape analysis was based on the Procrustes method. The aligned shapes were used and treated in TPS series tpsDig, tpsUtil and tpsRegr. The first task was to test the index of fluctuating asymmetry using a 2 way ANOVA of homologous points to identify the most suitable species for testing developmental stability in unfavourable environments. The second task included the analysis of the homologous bilaterally-symmetrical distances in comparison to the index of fluctuating asymmetry. Fluctuating asymmetry showed a small fraction of the variability in flower shape. One species (Digitalis purpurea L.) showed the highest level of FA indicating deviation from developmental stability. The index of FA data on homologous landmarks corresponded to the data on fluctuating asymmetry index of distances.

The paper discusses the features of school biology education research organization in the context of the implementation of the Federal State Educational Standard of General Secondary Education. It is shown that the specificity of Biology as a school subject provides enormous opportunities to research activities for schoolchildren. It contributes to the results that comply with the Federal State Educational Standard, improves critical thinking and learning ability developing. This study shows the most common areas of biological research presented at school scientific conferences and olympiads of various levels. New and rarely used topics are proposed for education research in Botany, Zoology, Human Anatomy and their subsections. When choosing topics for their studies, authors recommend taking into account the students interests, age, ability to complete the research within a relatively short time at school or in other education organizations, scientific relevance and usefulness for the participants and regional approach. It is stated that the organization of theoretical and experimental research should be based on the scientific logic, which will improve students research abilities. The paper reveals typical problems of teachers associated with the choice of research topics, problem statement and choice of methods for studying natural objects.

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