This paper describes the technical information and performance of a new multi-objective chamber system enabling the control of environmental variables (e.g., temperature, CO2, air humidity, wind speed, and UV-B radiation) for understanding plant responses to climate change. Over a whole growing season, four different climate scenarios were evenly programmed into the system’s 16 chambers as ambient environment (AMB), elevated temperature (ET), elevated CO2 concentration (EC) and elevated temperature and CO2 concentration (ETC). Simultaneously, the chamber effects were assessed regarding the physiological responses and growth of a boreal perennial grass (reed canary grass, Phalaris arundinacea L.). During the growing season, the chamber system provided a wide variety of climatic conditions for air temperature (T a), relative humidity (RH) and CO2 concentration (C a) in the AMB chambers following outside conditions. The target temperature (+3.5°C) was achieved to a good degree in the ET and ETC chambers, being on average 3.3°C and 3.7°C higher than ambient conditions, respectively. The target concentration of CO2 (700 ppm) was also well achieved in the EC and ETC chambers, being on average 704 ppm and 703 ppm, respectively. The stable airflow condition inside all of the chambers provided a homogeneous distribution of gases and temperature. The decreases in RH and increases in vapour pressure deficit (VPD) in the elevated temperature chambers were also maintained at a low level. Chamber effects were observed, with some physiological and growth parameters of plants being significantly lower in the AMB chambers, compared to outside conditions. The plant growth was negatively affected by the reduced radiation inside the chambers., X. Zhou ... [et al.]., and Obsahuje bibliografii
Miscanthus is one of the most promising bioenergy crops with high photosynthetic nitrogen-use efficiency (PNUE). It is unclear how nitrogen (N) influences the photosynthesis in Miscanthus. Among three Miscanthus genotypes, the net photosynthetic rate (PN) under the different light intensity and CO2 concentration was measured at three levels of N: 0, 100, and 200 kg ha-1. The concentrations of chlorophyll, soluble protein, phosphoenolpyruvate carboxylase (PEPC), ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit, leaf anatomy and carbon isotope discrimination (Δ) in the leaf were analyzed to probe the response of photosynthesis in Miscanthus genotypes to N levels. PN in all genotypes rose significantly as N application increased. The initial slope of response curves of PN to Ci was promoted by N application in all genotypes. Both stomatal conductance and Ci were increased with increased N supply, indicating that stomatal factors played an important role in increasing PN. At a given Ci, PN in all genotypes was enhanced by N, implying that nonstomatal factors might also play an important role in increasing PN. Miscanthus markedly regulated N investment into PEPC rather than the Rubisco large subunit under higher N conditions. Bundle sheath leakiness of CO2 was constant at about 0.35 for all N levels. Therefore, N enhanced the photosynthesis of Miscanthus mainly by increasing stomatal conductance and PEPC concentration., X.-P. Feng ... [et al.]., and Obsahuje bibliografii
For Tunisian olive tree orchards, nitrogen deficiency is an important nutritional problem, in addition to the availability of water. Establishment of relationships between nutrients such as nitrogen and ecophysiological parameters is a promising method to manage fertilisation at orchard level. Therefore, a nitrogen stress experiment with one-year-old olive trees (Olea europaea L. 'Koroneiki' and 'Meski') was conducted with trees respectively subjected to four nitrogen supply regimes (23.96 meq l-1, 9.58 meq l-1, 4.79 meq l-1 and 0 meq l-1 NO3-).
The current paper focuses on the use of the SPAD-502 portable chlorophyll (Chl) meter, a nondestructive method for fertilisation management under nitrogen stress conditions of olive trees. Maximum net photosynthetic assimilation rates, chlorophyll fluorescence parameters and the SPAD Chl index were therefore measured simultaneously and the Chl and nitrogen content of the leaves were analysed. Significant correlations were established in the olive tree leaves between SPAD-502 readings on the one hand and Chl content, nitrogen content, photosynthetic assimilation rate, and Chl fluorescence parameters (ΦPSII and ETR) on the other hand. and O. Boussadia ... [et al.].
Leaf area of a plant is essential to understand the interaction between plant growth and environment. This useful variable can be determined by using direct (some expensive instruments) and indirect (prediction models) methods. Leaf area of a plant can be predicted by accurate and simple leaf area models without damaging the plant, thus, provide researchers with many advantages in horticultural experiments. Several leaf-area prediction models have been produced for some plant species in optimum conditions, but not for a plant grown under stress conditions. This study was conducted to develop leaf area estimation models by using linear measurements such as lamina length and width by multiple regression analysis for green pepper grown under different stress conditions. For this purpose, two experiments were conducted in a greenhouse. The first experiment focused to determine leaf area of green pepper grown under six different levels of irrigation water salinity (0.65, 2.0, 3.0, 4.0, 5.0, and 7.0 dS m-1) and the other under four different irrigation regime (amount of applied water was 1.43, 1.0, 0.75, and 0.50 times of required water). In addition to general models for each experiment, prediction models of green pepper for each treatment of irrigation water salinity and of irrigation regime experiments were obtained. Validations of the models for both experiments were realized by using the measurements belong to leaf samples allocated for validation purposes. As a result, the determined equations can simply and readily be used in prediction of leaf area of green pepper grown under salinity and water stress conditions. The use of such models enable researchers to measure leaf area on the same plants during the plant growth period and, at the same time, may reduce variability in experiments. and B. Cemek ... [et al.].
Nondestructive approach of modeling leaf area could be useful for plant growth estimation especially when number of available plants is limited and/or experiment demands repeated estimation of leaf area over a time scale. A total of 1,280 leaves were selected randomly from eight different morphotypes of som (Persea bombycina) established at randomized complete block design under recommended cultural regimes in field. Maximum leaf laminar width (B), length (L) and their squares B2, L2; leaf area (LA), and lamina length × width (L×B) were determined over two successive seasons. Leaf parameters were significantly affected by morphotypes; but seasons had nonsignificant impacts on tested features. Therefore, pooled seasonal morphotype means of each parameter were used to establish relationship with LA. L and its square L2 did not provide accurate models for LA predictions. Considerably better models were obtained by using B (y = 2.984 + 7.9664 x, R2 = 0.615, P≥0.001, n = 119) and B2 (y = 12.784+ 0.9604 x, R2 = 0.605, P≥0.001, n = 119) as independent variables. However, maximum accuracy of prediction of LA could be achieved through a simple linear relationship of L×B (y = 8.2203 + 0.4224 x, R2 = 0.843, P≥0.0001, n = 119). The model (LA:L×B) was validated with randomly selected leaf samples (n = 360) of som morphotypes and highly significant (P≤0.001) linear function was found between actual and predicted LAs. Therefore, the last model may consider adequate to predict leaf area of all cultivars of som with sufficient fidelity. and S. Chattopadhyay ... [et al.].
Sklenobýl bezlistý (Epipogium aphyllum) patří mezi nejvzácnější druhy naší flóry. Roste v bučinách a jehličnatých lesích s humózní půdou, často na lesních prameništích. Ještě donedávna byl v Čechách hodnocen jako nezvěstný. V r. 2006 se ale podařilo objevit několik malých lokalit na Šumavském Boubíně, poté v r. 2008 i jedna lokalita v Krkonoších. V červnu r. 2013 v náplavech Jizery a hned u cesty nedaleko Kořenova se podařilo objevit další dvě mikrolokality tohoto ohroženého druhu. Bylo by velmi povzbuzující domnívat se, že nárůst počtu lokalit nejen sklenobýlu, ale i jiných ohrožených druhů indikuje zlepšující se stav prostředí., Epipogium aphyllum is one of the rarest plant species of the Czech flora. It grows in humus-rich soil in beech and spruce forests, often in the vicinity of forest springs. The species has been considered missing in Bohemia until recent discoveries of a few sites in Boubín in the Šumava Mts. (Bohemian Forest, 2006) and in the Krkonoše Mts. (Giant Mts., 2008). Two new populations were found in the Giant Mts. in June 2013 - in alluvial deposits of the Jizera river and along the forest road close to the Kořenov village., and Pavla Čížková, Kamila Lencová, Pavel Hubený.
Článek se věnuje nově popsanému rodu Oreojuncus Záveská Drábková et Kirschner, který zahrnuje dva druhy - Oreojuncus trifidus a Oreojuncus monanthos. V České republice se vyskytuje pouze O. trifidus, sítina horská trojklanná, které je věnována větší pozornost. Rod Oreojuncus byl tradičně zařazován mezi sítiny (Juncus) sekce Steirochloa, avšak na základě komplexního výzkumu zahrnujícího fylogenetickou analýzu molekulárních dat a revizi morfologie byl vyčleněn jako samostatný, osmý rod čeledi sítinovitých (Juncaceae)., The new genus Oreojuncus Záveská Drábková et Kirschner has been described, with two species - O. trifidus and O. monanthos. Attention is given to the first species, which occurs in the Czech Republic. The genus Oreojuncus has been traditionally included in the Juncus sect. Steirochloa; however, complex research based on phylogenetic analysis of the molecular data and morphological revision revealed the necessity to establish this eighth genus in the Juncaceae family., and Lenka Záveská Drábková.
Karel Domin (1882-1953) byl významný český botanik a vysokoškolský pedagog. Vystudoval a působil na Univerzitě Karlově, byl děkanem Přírodovědecké fakulty a v letech 1933-1934 dokonce univerzitním rektorem, s jeho jménem je spojen boj o insignie. Byl dlouholetým ředitelem Botanického ústavu Univerzity Karlovy. Ve své profesi byl mimořádně aktivní, v letech 1914-1945 byl předsedou České botanické společnosti, o jejíž vznik se zasloužil, publikoval řadu odborných i populárně naučných prací. Věnoval se také politické činnosti, v letech 1935-1939 byl senátorem za Národní sjednocení. Po 2. světové válce byl nařčen z kolaborace a zbaven všech funkcí. Přestože byl Národním soudem veškerých obvinění zbaven, do veřejného života se již nevrátil a roku 1949 byl penzionován., Karel Domin (1882-1953) was the important Czech botanist, politician, professor (a head of the University Botanical Institute), the dean of the Faculty of Science of Charles University in Prague and the chancellor of the University. He was very active both in his professional activities (e. g. he was a chairman of the Czech Botanical Society in 1914-1945), and in public and political activities (e. g. a National Assembly senator 1935-1939, representative of the National Democratic Party). After the World War II he was accused of collaboration and suspended from all his public and professional jobs, functions and offices. (Translated by Hana Barvíková.), and Překlad resumé: Hana Barvíková