High salt concentration is a major abiotic stress limiting plant growth and productivity in many areas of the world. Elaeagnus angustifolia L. adapts to adverse environments and is widely planted in the western region of China as a windbreaker and for landscape and soil stabilization. High salt concentrations inhibited photosynthesis of E. angustifolia, but the mechanism is not known. In this paper, RNA-sequencing was used to investigate effects of salt stress on the photosynthetic characteristics of the species. In total, 584 genes were identified and involved in photosynthetic pathways. The downregulation of genes that encode key enzymes involved in photosynthesis and genes correlated to important structures in photosystem and light-harvesting complexes might be the main reason, particularly, the downregulation of the gene that encodes magnesium chelatase. This would decrease the activity of enzymes involved in chlorophyll synthesis and the downregulation of the key gene that encodes Rubisco, and thereby decreases enzyme activity and the protein content of Rubisco., J. Lin, J. P. Li, F. Yuan, Z. Yang, B. S. Wang, M. Chen., and Obsahuje bibliografii
RNA gel hybridization showed that the expression of monodehydroascorbate reductase (MDHAR) in the wild type (WT) tomato was decreased firstly and then increased under salt- and polyethylene glycol (PEG)-induced osmotic stress, and the maximum level was observed after treatment for 12 h. WT, sense transgenic and antisense transgenic tomato plants were used to analyze the antioxidative ability to cope with osmotic stresses. After salt stress, the fresh mass (FM) and height of sense transgenic lines were greater than those of antisense lines and WT plants. Under salt and PEG treatments, sense transgenic plants showed a lower level of hydrogen peroxide (H2O2) and malondialdehyde (MDA), a higher net photosynthetic rate (PN), and the maximal photochemical efficiency of PSII (Fv/Fm) compared with WT and antisense transgenic plants. Moreover, sense lines maintained higher ascorbate peroxidase (APX) activity than WT and antisense plants under salt- and PEG-induced osmotic stress. These results indicate that chloroplastic MDHAR plays an important role in alleviating photoinhibition of PSII by elevating ascorbate (AsA) level under salt- and PEG-induced osmotic stress., F. Li ... [et al.]., and Obsahuje bibliografii
Interactions involving host plants (cowpea, groundnut, cotton, sunflower, greengram, blackgram) an insect herbivore, black legume aphid Aphis craccivora Koch (Hemiptera: Aphididae) and a predator, the zigzag beetle Cheilomenes sexmaculata (Fabricius) (Coleoptera: Coccinellidae) were investigated during 2014-2015. The preference of the aphid A. craccivora for host plants measured in terms of growth and multiplication was cowpea > groundnut > greengram > blackgram > sunflower > cotton (most preferred to least preferred). Cowpea was the most preferred host plant for growth and multiplication of A. craccivora. Aphid's oviposition period was longest, fecundity greatest; adult longevity longest (188.40 ± 28.87 h; 52.00 ± 10.92; 231.60 ± 40.41 h), and nymphal mortality was lowest (0%) when reared on cowpea followed by groundnut, greengram and blackgram. Aphids had highest nymphal mortality (100%), with very few or no live adults produced, when reared on sunflower and cotton, the least preferred host of A. craccivora in this study. At the third trophic level, both the larvae and the adults of the coccinellid, Cheilomenes sexmaculata, consumed more of the aphids reared on groundnut than of those reared on blackgram, greengram, cowpea, sunflower and cotton. The biochemical constituents (phenols) present in cotton and sunflower, which contributed to the aphid's nymphal mortality, also affected the feeding behaviour of the coccinellid., Snehasish Routray, Karnam V. Hari Prasad., and Obsahuje bibliografii
Pigeon, doves and songbirds are hosts of the parasite Trichomonas gallinae (Rivolta, 1878), which causes avian trichomonosis. Raptors are infected when they digest infected prey. A high percentage of the diet of Eurasian sparrowhawk Accipiter nisus (Linnaeus) is comprised of birds. During the breeding season 2012 and 2013, we clinically tested 298 nestling Eurasian sparrowhawks from urban and rural areas of the Czech Republic for the presence of trichomonads. Sparrowhawk nestlings in the urban area were more infected (32.9%) than in the rural area (12.2%) in 2012 (χ2 = 6.184, P = 0.045). The number of infected nestlings dropped in the urban area (5.4%) and remained similar in the rural area (16.6%) in 2013. Sequences of ITS region and SSU rDNA confirmed that the isolates from infected sparrowhawk nestlings belonged to Trichomonas gallinae., Tomáš Kunca, Pavla Smejkalová, Ivan Čepička., and Obsahuje bibliografii
Článek stručně shrnuje základní adaptace xerotermních rostlin. K těm patří i povrchové struktury vzniklé z epidermis. Blíže je v textu pojednáno o krycích chlupech (trichomech), jejich funkci a morfologii. Článek doplňuji fotografie různých typů těchto trichomů., This article briefly summarises essential adaptations of xerothermic species. These include epidermal structures covering plant surface. The plant hairs (trichomes), their function and morphology are described in detail. The text is supplemented with photos of some trichome types., and Hana Mašková.
Evropsky významná lokalita (EVL) v regionu Trojstátí Čech, Bavorska a Saska nabízí přírodovědně a turisticky zajímavé území. Místní příroda ukrývá ohrožené a významné druhy fauny i flóry. Nejvýznamnějším zástupcem je kriticky ohrožený mlž perlorodka říční (Margaritifera margaritifera). Oblast je možné projít po naučné stezce Na cestě k Trojstátí, která představuje místní zajímavosti., The Site of Community Importance (SCI) located in the region of the Bohemian, Bavarian and Saxon borders is an interesting area from the viewpoint of natural sciences and tourism. The local landscape hosts rare and endangered species of fauna and flora. The most important representative is the critically endangered Freshwater Pearl Mussel (Margaritifera margaritifera). The area can be explored along the nature trail called „Na cestě k Trojstátí“ which introduces all local places of interest., and Josef Levý.
Ovipositing females from invasive (Krasnodar Territory of Russia) and native (Far East of Russia) populations of Harmonia axyridis were fed one of a set of diets ranging from 50 Myzus persicae aphids every day to 1 aphid every 10 days and all were also provided with a 10% sugar solution. The experiment was conducted at 20°C under short (12 h) and long (18 h) day conditions. Most of the females from the native population that consumed 50 or 10 aphids per day continued to oviposit under both long and short day conditions. Females that consumed 1 aphid per day or every 2 days practically stopped laying eggs but under long day conditions their ovaries were still active, whereas under short day conditions ca 50% of them were reproductively inactive (only germaria present) and had a well-developed fat body. Further reduction in diet resulted in an increase in the proportion of reproductively inactive females. However, about half of the females that terminated oogenesis under long day conditions had poorly developed fat bodies, which indicates that diapause was not induced. For the females from the invasive population, both photoperiodic and trophic effects were weak: under short day conditions, some females entered diapause when prey was abundant, whereas about 50% (independent of photoperiod) did not enter diapause when starved. This risk-spreading strategy, possibly, facilitates the adaptation of this invasive ladybird to unpredictable environmental conditions., Antonina A. Ovchinnikova, Andrey N. Ovchinnikov, Margarita Yu. Dolgovskaya, Sergey Ya. Reznik, Natalia A. Belyakova., and Obsahuje bibliografii
1_The arboricolous dolichoderine ant Liometopum microcephalum (Panzer, 1798) is considered to be mainly predatory, although there are some reports of it tending aphids. The main objective of the present study was to confirm that this ant has a trophobiotic relationship with aphids and assess seasonal differences in its utilization of honeydew. We hypothesized that the worker ants on trees where they have their nest (nest tree) and trees where they are foraging (foraging trees) should differ in gaster mass and sugar content depending on their direction of movement, and that both should be highest in spring. From spring to summer 2009, ascending and descending workers were collected from nest and foraging trees at a locality in South Moravia, Czech Republic. Mass of their gasters and their content of total and reducing sugars were measured using chemical (photometric) methods. Differences in gaster mass confirmed the flow of liquid food from foraging to nest trees, but there were no significant between-month differences. Contents of total and reducing sugars were positively correlated with gaster mass. The gasters of workers descending from foraging trees contained significantly more reducing sugars than those of workers descending or ascending nest trees. The content of reducing sugars was lowest at the beginning of the ants’ activity period in April and highest in June, with a non-significant drop in July. Results for total sugars were similar, with the decrease in July being significant. The concentration of sugars in the gasters of workers ascending and descending nest trees did not differ significantly but the absolute content of total sugars was higher in the gasters of ascending ants., 2_Results from foraging trees confirmed that the ants collected the honeydew from these trees. Possible reasons for the ambigous results for nest trees are discussed. We conclude that trophobiosis is an important component of the nutritional biology of L. microcephalum., Jiří Schlaghamerský ... []., and Obsahuje seznam literatury
Tropické lesy ostrova Borneo v jihovýchodní Asii jsou celosvětově výjimečné vysokou biodiverzitou různých skupin organismů. Jejich podoba byla formována mimo jiné během čtvrtohorního kolísání hladiny světových oceánů, kdy byly ostrovy sundské oblasti vzájemně propojeny či odděleny, což mělo vliv na migraci organismů. Současná diverzita lesů Bornea sleduje gradient nadmořské výšky a vlastnosti substrátů, přičemž můžeme rozlišit několik hlavních typů lesa. V posledních desetiletích jsme svědky masivní těžby lesů, které jsou mnohde převáděny na plantáže palmy olejné., Tropical forests of the island of Borneo in South East Asia harbour an extraordinary high biodiversity of various groups of organisms. They have been shaped, among other influences, by the Quaternary fluctuations of the level of world’s oceans, connecting or dividing islands within the Sundaland, which has affected migration of species. The present diversity of forests in Borneo follows an elevational gradient and substrate properties, thus forming several main forest types. Over the past few decades, we have witnessed massive logging and transformation of forests into oil palm (Elaeis guineensis) plantations., Radim Hédl., and Obsahuje seznam literatury
Borneo je ostrovem se zajímavou geomorfologií a překvapivě různorodou geologií. Oba faktory se spolu s historickým vývojem určujícím migrace druhů podílely na současné pestrosti bornejské flóry. Pozoruhodné funkční a taxonomické skupiny rostlin najdeme nejen v zapojeném lese, ale také nad horní hranicí lesa, v pobřežních prostředích, podél vodních toků a jinde. V krátkosti jsou představeny vybrané funční skupiny epifyty, epifyly, liány, masožravé rostliny s význačným rodem láčkovka, nezelené rostliny, rheofyty a alpinské rostliny, mezi kterými nalezneme i trávy temeprátních oblastí. Z pozoruhodných taxonomických skupin představujeme zázvory, áronovité, begonie a pěnišníky, které mají na Borneu jedno z center své diverzity., Borneo is an island with conspicuous geomorphology and variable geology. Both factors have contributed, along with historical development determining species migrations, to the present richness of the flora of Borneo. Remarkable functional and taxonomic groups of herbs occur not only in closed forests, but also above the timberline, in coastal and riparian habitats, and elsewhere. Selected functional groups are briefly introduced: epiphytes, epiphylles, rheophytes, carnivorous, achlorophyllous and alpine plants. From conspicuous taxonomic groups, we introduce gingers, aroids, begonias and rhododendrons., and Martin Dančák ... [et al.].