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WOS: 000273140500002 In the present study, models for estimation of the content of main secondary metabolites, namely hypericin, pseudohypericin, and hyperforin, were developed for Hypericum origanifolium Willd. (Guttiferae), Hypericum perfoliatum L., and Hypericum montbretii Spach., growing in Northern Turkey. Wild growing plants were harvested at vegetative, floral budding, full flowering, fresh fruiting, and mature fruiting stages and dissected into stem, leaf, and reproductive tissues. Actual secondary metabolite contents of plant materials were measured by a high performance liquid chromatography method. Multiple regression analysis using the Excel 2003 computer package was performed for each species and chemical separately to develop multiple regression models. The equation produced for predicting the content of secondary metabolites in different tissues of the species was formulized as: SMC=[a + (b(1) x S) + (b(2) x L) + (b(3) x RP) + (b(4) x S-2) + (b(5) x (1/RP))], where SMC is the secondary metabolite content of the whole plant, S is the secondary metabolite content of the stem, L is the secondary metabolite content of the leaf, RP is the secondary metabolite content of the reproductive parts, and a, b(1), b(2), b(3), b(4), and b(5) are coefficients. The R-2 coefficient values between predicted and observed contents of secondary metabolites were determined as 0.99 for H. origanifolium, 0.95-0.98 for H. perfoliatum, and 0.90-0.99 for H. montbretii. All R-2 values and standard errors were found to be significant at the p < 0.05 level.

11 pags, 4 figs, 2 tabs, Giant rosettes are ones of the most striking features of the vegetation in the high tropical Andes, with Coespeletia moritziana reaching the highest altitudes up to 4,600 m a. s. l. Different from other giant rosettes, this species grows on rock outcrops with poorly developed soils and where water availability may be limited. Two questions are addressed in this study: How does this species respond in terms of water relations to maintain favorable gas-exchange conditions? Considering that adult plants rely on a water-reserving central pith, how do early stages respond to this environment's extreme conditions? Water relations and gas-exchange studies were carried out on juveniles, intermediate and adult C. moritziana plants during wet and dry seasons in Páramo de Piedras Blancas at 4,200 m a. s. l. Adult plants maintained higher leaf water potentials (Ψ L) during the wet season, however, no differences between stages were found for the dry season. Minimum dry season Ψ L were never near the turgor loss point in any of the stages. Juveniles show a more strict stomatal control during the dry season to maintain a favorable water status. Net photosynthesis significantly decreased in intermediate and juvenile stages from wet to dry seasons. Our results suggest that C. moritziana resists more extreme conditions compared to other Andean giant rosettes © 2012 Springer Science+Business Media B.V.

A review of the published literature about foliar transfer radionuclides to cereal grains was carried out with a special interest for translocation factors. Translocation describes the distribution of radionuclides within the plant after foliar deposition and radionuclide absorption onto the surface of leaves. It mainly depends on elements and the plant growth stage. The collected data were derived from both in-field and greenhouse experiments. They were analysed in order to select those coming from a contamination simulating a sprinkling irrigation or a rain. The data set contains 307 values. For each radionuclide the translocation factor values were sorted according to 5 characteristic stages of the cereal vegetative cycle: leaf development-tillering, stem elongation, earing-flowering, grain growth and ripening. Wheat, barley and rye have been treated together, independently of rice. For mobile elements such as cesium, the translocation factor is maximum when the contamination occurred at the earing-flowering stage. For less mobile elements such as strontium this maximum occurred for a foliar contamination at the grain growth stage. This review enabled us to propose the most probable value as well as the range of variation of translocation factors for some radionuclides according to the cereal vegetative cycle. Moreover, from these results, a radionuclide classification is proposed according to three mobility groups. © 2008 Elsevier Ltd. All rights reserved.