Number of results to display per page
Search Results
52. Dva nové druhy pcháčů v pražské květeně: může mít Praha po 150 letech novou Květenu?
- Creator:
- Jiří Hadinec
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Botanika, flóra, pcháč, Praha (Česko), 2, and 58
- Language:
- Czech
- Description:
- This article provides brief information on the history and prominent botanists exploring the surroundings of Prague. it is dedicated to V. Skalický, who intensively studied Prague flora in the second half of the 20th century. Two new sites of C. rivulare and C. heterophyllum in Prague are described. While the occurrence of C. rivulare can be found in numerous and vital populations in the Šárecký potok valley. and Jiří Hadinec.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
53. Dynamika horských smrčin na Šumavě
- Creator:
- Vojtěch Čada, Brůna, Josef, Miroslav Svoboda, and Wild, Jan
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Botanika, smrk, Šumava (pohoří), 2, and 58
- Language:
- Czech
- Description:
- Understanding the history of coniferous forests and their natural changes over time is critical for proper and effective forest management. The text describes the origin and disturbance history of the mountain Norway Spruce (Picea abies) forests in the Šumava Mts. (Bohemian Forest) using tree-ring and archival documents analyses. Severe and extensive natural disturbances play and have played a fundamental role in forest structure and dynamics. Part of the territory has been shaped by forest management. and Vojtěch Čada ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
54. Ecophysiological characteristics of two carrot (Daucus carota L.) cultivars in response to agroecological factors and nitrogen application
- Creator:
- Thiagarajan, A., Lada, R., and Adams, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Daucas carota, foliar nitrogen, photosynthesis, processing carrots, water-use efficiency, 2, and 58
- Language:
- Multiple languages
- Description:
- Plant density, planting time, harvest timing, and nitrogen influence on short-term gas-exchange properties of carrot cultivars, Topcut and Sugarsnax (Daucus carota L.) were investigated under field conditions. Net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E) differed significantly with the cultivars studied. Both planting and harvest timing changed the midday PN rates. P N increased as harvest timing advanced regardless of planting time. Late planting combined with late harvesting registered the maximum P N rates (4.5 μmol m-2 s-1). The water-use efficiency (WUE) was altered by temperature at different harvest timings along with the choice of cultivar. Early harvested Sugarsnax had a higher WUE (2.29 mmol mol-1) than TopCut (1.64 mmol mol-1) as Sugarsnax exhibited more stomatal conductance than TopCut. These changes were principally governed by fluctuations observed with air temperature and photosynthetic photon flux density (PPFD) and altered by the sensitivity of the cultivars to ecological factors. Plant density did not affect the photosynthetic gas-exchange parameters. Our results suggest that carrots manage high population density solely through morphological adaptations with no photosynthetic adjustments. Carrot leaves responded to N application in a curvilinear fashion in both cultivars. N did not alter gs, E, or WUE in carrots. N, applied at a rate of 150 kg N ha-1, increased foliar N up to 2.98%. We conclude that 2.98% of foliar N is sufficient to achieve the maximum photosynthetic rates in processing carrots., A. Thiagarajan, R. Lada, A. Adams., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
55. Ecophysiological response in leaves of Caragana microphylla to different soil phosphorus levels
- Creator:
- Zhao, T. T., Zhao, N. X., and Gao, Y. B.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, adaptive strategy, leaf functional traits, leaf phosphorus allocation, soil phosphorus level, 2, and 58
- Language:
- Multiple languages
- Description:
- Phosphorus (P) is one of the limiting mineral nutrient elements in the typical steppe of Inner Mongolia, China. In order to find out the adaptive strategy of Caragana microphylla to low soil P status, we grew plants in P-deficient soil in April 2009 and gave a gradient of P addition ranging from 0 to 60 mg(P) kg-1(soil) from May 2010. Leaf traits were measured in September 2010. Both leaf growth and light-saturated photosynthetic rate (P max) were similar among different groups. Leaf nitrogen (N):P ratio indicated that the growth of C. microphylla was not P-limited in most of the Inner Mongolia typical steppe, which had an average soil available P content equal to 3.61 mg kg-1. The optimal P addition was 20 mg(P) kg-1(soil) for two-year-old plants of C. microphylla. Leaf mass area (LMA) and leaf dry matter content (LDMC) were enhanced with low P, and significantly negatively correlated with photosynthetic N-use efficiency (PNUE). Photosynthetic P-use efficiency (PPUE) increased with decreasing soil P and increasing leaf inorganic P (Pi): organic P (Po) ratio, and showed no significant negative correlation with LMA or LDMC. P max of C. microphylla did not decline so sharply as it was anticipated. The reason for this phenomenon might be due to the increased PPUE through regulating the leaf total P allocation. C. microphylla had high P-use efficiency via both high PPUE and long P-retention time at low-P supply. The adaptation of C. microphylla to low-P supply provided a new explanation for the increased distribution of the species in the degraded natural grassland in Inner Mongolia, China., T. T. Zhao, N. X. Zhao, Y. B. Gao., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
56. Ecophysiological responses of Caragana korshinskii Kom. under extreme drought stress: leaf abscission and stem survives
- Creator:
- Xu, D. H., Fang, X. W., Su, P. X., and Wang, G.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, chlorophyll content, chlorophyll fluorescence, fluorescence quenching, photosynthesis, stress response, 2, and 58
- Language:
- Multiple languages
- Description:
- Caragana korshinskii Kom. is a perennial xerophytic shrub, well known for its ability to resist drought. In order to study ecophysiological responses of C. korshinskii under extreme drought stress and subsequent rehydration, diurnal patterns of gas exchange and chlorophyll (Chl) fluorescence parameters of photosystem II as well as Chl content were analyzed. Plant responses to extreme drought included (1) leaf abscission and using stem for photosynthesis, (2) improved instantaneous water-use efficiency, (3) decreased photosynthetic rate and partly closed stomata owing to leaf abscission and low water status, (4) decreased maximum photochemical efficiency of photosystem II (PSII) (variable to maximum fluorescence ratio, Fv/Fm), quantum efficiency of noncyclic electron transport of PSII, and Chl a and Chl b. Four days after rehydration, new leaves budded from stems. In the rewatered plants, the chloroplast function was restored, the gas exchange and Chl fluorescence returned to a similar level as control plant. The above result indicated that maintaining an active stem system after leaf abscission during extreme drought stress may be the foundation which engenders these mechanisms rapid regrowth for C. korshinskii in arid environment., D. H. Xu ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
57. Editorial
- Creator:
- Jan Suda and Šrotová, Jana
- Format:
- Type:
- article, úvodníky, model:article, and TEXT
- Subject:
- Botanika, 2, and 58
- Language:
- Czech
- Description:
- Jan Suda a Jana Šrotová.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
58. Effect of bicarbonate treatment on photosynthetic assimilation of inorganic carbon in two plant species of Moraceae
- Creator:
- Wu, Y. Y. and Xing, D. K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, bicarbonate-use capacity, carbonic anhydrase, chlorophyll fluorescence, photosynthesis, stable hydrogen isotope, 2, and 58
- Language:
- Multiple languages
- Description:
- Excessive levels of bicarbonate adversely affect the growth and metabolism of plants. Broussonetia papyrifera (L.) Vent. and Morus alba L., belonging to family Moraceae, possess the favorable characteristics of rapid growth and adaptability to adverse environments. We examined the response of these two plant species to bicarbonate stress in terms of photosynthetic assimilation of inorganic carbon. They were exposed to 10 mM sodium bicarbonate in the culture solution for 20 days. The photosynthetic response was determined by measuring the net photosynthetic rate of the leaf, water-use efficiency, and chlorophyll fluorescence on days 10 and 20. The bicarbonate-use capacity of the plants was studied by measuring the carbonic anhydrase activity and the compositions of the stable carbon and hydrogen isotopes. The photosynthetic response to high concentration of bicarbonate varied with plant species and treatment durations. High concentrations of bicarbonate decreased the photosynthetic assimilation of inorganic carbon in the two plant species to half that in the control plants on day 10. Bicarbonate treatment did not cause any damage to the reaction centers of photosystem II in Morus alba; it, however, caused a decline in the quantum efficiency of photosystem II in B. papyrifera on day 20. Moreover, B. papyrifera had a greater bicarbonate-use capacity than M. alba because carbonic anhydrase converted bicarbonate to CO2 and H2O to a greater extent in B. papyrifera. This study showed that the effect of bicarbonate on photosynthetic carbon metabolism in plants was dual. Therefore, the concentration of bicarbonate in the soil should first be considered during afforestation and ecological restoration in karst areas., Y. Y. Wu, D. K. Xing., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
59. Effect of Ca/Mg ions ratio on copper accumulation, photosynthetic activity and growth of Cu2+-treated Salix viminalis L. ‘Cannabina’
- Creator:
- Borowiak, K., Drzewiecka, K., Magdziak, Z., Gąsecka, M., and Mleczek, M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Ca/Mg ions ratio, copper, net photosythesis rate, phytoremediation, Salix sp., stomatal conductance, transpiration rate, 2, and 58
- Language:
- Multiple languages
- Description:
- The aim of the study was to the assess the influence of Ca/Mg ions ratio on the photosynthetic activity of Salix viminalis L. ‘Cannabina’ plants cultivated in medium enriched with Cu(NO3)2. The experiment was conducted in controlled conditions in a phytotron for 21 days; hence the early plant response was tested. Plants were cultivated with different Ca/Mg ions ratios, i.e. (4:1)l, (4:1)h, and 1:10. Plants were additionally treated with Cu(NO3)2 at 1, 2, and 3 mM concentration in cultivation medium. Net photosynthetic rate, stomatal conductance and transpiration were measured after the first, second and third week of cultivation. Additionally, chlorophyll content, leaf morphology, root biomass and copper accumulation in leaves and roots were investigated. The investigations revealed differences in plant response to particular treatments - differences in Cu accumulation for particular Ca/Mg ions ratios were detected. It seems that plants are adapted to high Cu2+ concentrations, when 1:10 Ca/Mg ions ratio is applied. The highest Cu accumulation in roots was noted for plants fertilized with 1:10 Ca/Mg ions ratio, together with high Cu translocation to above-ground plant organs, which suggests its higher potential in phytoremediation., K. Borowiak ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
60. Effect of Glomus mosseae on chlorophyll content, chlorophyll fluorescence parameters, and chloroplast ultrastructure of beach plum (Prunus maritima) under NaCl stress
- Creator:
- Zai, X. M., Zhu, S. N., Qin, P., Wang, X. Y., Che, L., and Luo, F. X.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, beach plum, chlorophyll content, chlorophyll fluorescence, chloroplast ultrastructure, Glomus mosseae, NaCl stress, 2, and 58
- Language:
- Multiple languages
- Description:
- The present study was undertaken to investigate the effect of Glomus mosseae on chlorophyll (Chl) content, Chl fluorescence parameters and chloroplast ultrastructure of beach plum seedlings under 2% NaCl stress. The results showed that compared to control, both Chl a and Chl b contents of NaCl + G. mosseae treatment were significantly lower during the salt stress, while Chl a/b ratio increased significantly. The increase of minimal fluorescence of darkadapted state (F0), and the decrease of maximal fluorescence of dark-adapted state (Fm) and variable fluorescence (Fv) values were inhibited. The maximum quantum yield of PSII photochemistry (Fv/Fm), the maximum energy transformation potential of PSII photochemistry (Fv/F0) and the effective quantum yield of PSII photochemistry (ΦPSII) increased significantly, especially the latter two variables. The values of the photochemical quenching coefficient (qP) and the nonphotochemical quenching (NPQ) were similar between G. mosseae inoculation and noninoculation. It could be concluded that G. mosseae inoculation could protect the photosystem II (PSII) of beach plum, enhance the efficiency of primary light energy conversion and improve the primitive response of photosynthesis under salinity stress. Meanwhile, G. mosseae inoculation was beneficial to maintain the integrity of thylakoid membrane and to protect the structure and function of chloroplast, which suggested that G. mosseae can alleviate the damage of NaCl stress to chloroplast., X. M. Zai ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public