Hasil untuk "Botany"

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DOAJ Open Access 2025
A novel green biosynthesis approach and structural characterization of Ag–Fe bimetallic nanoparticles using the red alga Galaxaura rugosa

Elham M. Ali, Ashraf Elsayed, Ahlam S. El Shehawy

Abstract A novel green and eco-friendly approach has been used to biosynthesize Ag–Fe bimetallic nanoparticles (Ag–FeBNPs) by using the water extract of the red alga species; Galaxaura rugosa. The surface plasmon resonance band of Ag–FeBNPs is positioned at 327 nm. X-ray diffraction analysis (XRD) illustrated the crystalline nature of biogenic nanoparticles with average diameters of 32.6 nm. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) showed that the particles have a crystalline spherical shape with a size range from 19.95 to 37.11 nm. Scanning electron microscopy (SEM) and Energy dispersive analysis (EDAX) give the surface morphology and elemental composition of Ag–FeBNPs, which are spherical in high intensity. Fourier transmittance infrared spectroscopy (FTIR) showed various stretching vibrations at 3421, 1598, 1384, 1035, and 865 cm−1. These findings suggest that biomolecules play a crucial role in forming and stabilizing Ag–FeBNPs. Zeta potential values show − 16.1 mV. This study demonstrates the promising future of Ag–FeBNPs for nanobiotechnology and nanoscience, offering an environmentally friendly and simple approach for nanoparticles biosynthesizing. In addition, the synthesized Ag–FeBNPs exhibit properties that make them suitable for potential applications in biomedical fields, environmental remediation, and catalysis.

Medicine, Science
DOAJ Open Access 2023
As good as human experts in detecting plant roots in minirhizotron images but efficient and reproducible: the convolutional neural network “RootDetector”

Bo Peters, Gesche Blume-Werry, Alexander Gillert et al.

Abstract Plant roots influence many ecological and biogeochemical processes, such as carbon, water and nutrient cycling. Because of difficult accessibility, knowledge on plant root growth dynamics in field conditions, however, is fragmentary at best. Minirhizotrons, i.e. transparent tubes placed in the substrate into which specialized cameras or circular scanners are inserted, facilitate the capture of high-resolution images of root dynamics at the soil-tube interface with little to no disturbance after the initial installation. Their use, especially in field studies with multiple species and heterogeneous substrates, though, is limited by the amount of work that subsequent manual tracing of roots in the images requires. Furthermore, the reproducibility and objectivity of manual root detection is questionable. Here, we use a Convolutional Neural Network (CNN) for the automatic detection of roots in minirhizotron images and compare the performance of our RootDetector with human analysts with different levels of expertise. Our minirhizotron data come from various wetlands on organic soils, i.e. highly heterogeneous substrates consisting of dead plant material, often times mainly roots, in various degrees of decomposition. This may be seen as one of the most challenging soil types for root segmentation in minirhizotron images. RootDetector showed a high capability to correctly segment root pixels in minirhizotron images from field observations (F1 = 0.6044; r2 compared to a human expert = 0.99). Reproducibility among humans, however, depended strongly on expertise level, with novices showing drastic variation among individual analysts and annotating on average more than 13-times higher root length/cm2 per image compared to expert analysts. CNNs such as RootDetector provide a reliable and efficient method for the detection of roots and root length in minirhizotron images even from challenging field conditions. Analyses with RootDetector thus save resources, are reproducible and objective, and are as accurate as manual analyses performed by human experts.

Medicine, Science
DOAJ Open Access 2022
Distribution patterns and industry planning of commonly used traditional Chinese medicinal plants in China

Zhang-Jian Shan, Jian-Fei Ye, Da-Cheng Hao et al.

Medicinal plants are the primary material basis for disease prevention and treatment in traditional Chinese medicine (TCM). The conservation and sustainable utilization of these medicinal plants is critical for the development of the TCM industry. However, wild medicinal plant resources have sharply declined in recent decades. To ameliorate the shortage of medicinal plant resources, it is essential to explore the development potential of the TCM industry in different geographical regions. For this purpose, we examined the spatial distribution of commonly used medicinal plants in China, the number of Chinese medicinal material markets, and the number of TCM decoction piece enterprises. Specifically, multispecies superimposition analysis and Thiessen polygons were used to reveal the optimal range for planting bulk medicinal plants and the ideal regions for building Chinese medicinal material markets, respectively. Furthermore, we quantitatively analyzed mismatches between the spatial distribution of commonly used medicinal plant richness, Chinese medicinal material markets, and TCM decoction piece enterprises. We found that the areas suitable for growing commonly used medicinal plants in China were mainly distributed in Hengduan Mountain, Nanling Mountain, Wuling Mountain, and Daba Mountain areas. The Thiessen polygon network based on Chinese medicinal material market localities showed there are currently fewer markets in southwestern, northwestern, and northeastern China than in central and southern China. TCM decoction piece enterprises are concentrated in a few provinces, such as Hebei and Jiangxi. We found that the distribution of commonly used medicinal plants, Chinese medicinal material markets and TCM decoction piece enterprises are mismatched in Henan, Shaanxi, Hunan, Hubei, Zhejiang, Fujian, Chongqing, and Xizang. We recommend strengthening development of the TCM industry in Henan, Hunan, Zhejiang, Shaanxi, Hubei, Chongqing, Fujian, and Xizang; building more Chinese medicinal material markets in southwestern, northwestern, and northeastern China; and establishing medicinal plant nurseries in resource-rich provinces to better protect and domesticate local medicinal plants.

Biology (General), Botany
DOAJ Open Access 2022
Performance of the Improved Priestley-Taylor Model for Simulating Evapotranspiration of Greenhouse Tomato at Different Growth Stages

Xuewen Gong, Guokui Bo, Hao Liu et al.

Mastering crop evapotranspiration (ET) and improving the accuracy of ET simulation is critical for optimizing the irrigation schedule and saving water resources, particularly for crops cultivated in a greenhouse. Taking greenhouse-grown tomato under drip irrigation as an example, two weighing lysimeters were used to monitor ET at two seasons (2019 and 2020), whilst meteorological factors inside the greenhouse were measured using an automatic weather station. Then the path analysis approach was employed to determine the main environmental control factors of ET. On this basis, an improved Priestley-Taylor (IPT) model was developed to simulate tomato ET at different growth stages by considering the influence of environmental changes on model parameters (e.g., leaf senescence coefficient, temperature constraint coefficient and soil evaporative water stress coefficient). Results showed that the average daily ET varied from 0.06 to 6.57 mm d<sup>−1</sup>, which were ~0.98, ~2.58, ~3.70 and ~3.32 mm/d at the initial, development, middle and late stages, respectively, with the total ET over the whole growth stage of ~333.0 mm. Net solar radiation (<i>R<sub>n</sub></i>) and vapor pressure deficit (VPD) were the direct influencing factors of ET, whereas air temperature (<i>T<sub>a</sub></i>) was the limiting factor and wind speed (<i>u</i><sub>2</sub>) had a little influence on ET. The order of correlation coefficients between meteorological factors and ET at two seasons was <i>R<sub>n</sub></i> > VPD > <i>T<sub>a</sub></i> > <i>u</i><sub>2</sub>. The IPT model can accurately simulate ET in hourly and daily scales. The root mean square error of hourly ET at four stages changed from 0.002 to 0.08 mm h<sup>−1</sup> and daily ET varied from 0.54 to 0.57 mm d<sup>−1</sup>. The IPT coefficient was close to the recommended PT coefficient (1.26) when the average <i>T<sub>a</sub></i> approaches 26 °C and LAI approaches 2.5 cm<sup>2</sup> cm<sup>−2</sup> in greenhouse conditions. Our results can provide a theoretical basis for further optimization of greenhouse crop irrigation schedules and improvement of water use efficiency.

DOAJ Open Access 2021
A new approach to mark termites (Cornitermes cumulans (Kollar) Blattodea: Isoptera) for laboratory bioassays

A. Marins, P. F. Cristaldo, L. R. Paiva et al.

Abstract Behavioral lab bioassays involving termites must be promptly performed to allow intended observations prior to death from dissecation, typical of these soft-bodied insects. To this end, topic markers have been proposed as an alternative to histological stains which, while not always toxic are inevitably lengthy to apply. Among recommended topic markers, gouache is easy to apply, dries out quickly, but it is known affect termites in the long run, being suitable only to short-term bioassays. Its alternative, colored glue, is also easy to apply, but it takes long to dry and it is too dense and heavy, being thus prone to affect termite walking patterns. Here we tested a mix of gouache and colored glue aiming to combine the qualities of both into a suitable topical marker for Cornitermes cumulans termites. Similar patterns of survival presented by marked and unmarked termites ruled out concerns about toxicity of this mixture. Such results were consistent across distinct group densities evidencing that the mixture does not interfere with, nor it is affected by, crowding effects. Because crowding regulates interindividual interactions and these underlie most behaviors, the mixture can be thought to be suitable to behavioral studies. We argue that this 1:2 glue:gouache mixture is an excellent alternative to mark termites for lab bioassays. Being atoxic, cheap, easy to apply, and non-invasive, this mixture may happen to be useful not only for termites but also in bioassaying other similarly soft-bodied insects.

Science, Biology (General)
DOAJ Open Access 2021
Can common mycorrhizal fungal networks be managed to enhance ecosystem functionality?

Pierre‐Louis Alaux, Yaqian Zhang, Lucy Gilbert et al.

Societal Impact Statement Mycorrhizal fungi are key components of soil biodiversity that offer potential to provide sustainable solutions for land management, notably in agriculture and forestry. Several studies conducted in controlled environments show that key functional attributes of common mycorrhizal networks (CMNs), which inter‐link different plants, are influenced by management practices. Here, we highlight the need to consider how land management affects the ubiquity and function of CMNs in nature to maximize the role of mycorrhizal fungi in enhancing ecosystem services. We emphasize that CMNs can sometimes negatively affect aspects of plant performance, but there remain major gaps in understanding before explicit consideration of CMN management can be delivered. Summary Most mycorrhizal fungi have the capacity to develop extensive extraradical mycelium, and thus have the potential to connect multiple plants and form a ‘common mycorrhizal network’. Several studies have shown that these networks can influence plant establishment, nutrition, productivity and defense, nutrient distribution and storage, and multitrophic interactions. However, many of these studies have focused on the importance of common mycorrhizal networks in ecological contexts and there has been less emphasis in managed systems, including croplands, grassland, agroforestry and forestry, on which humankind relies. Here we review the evidence of the potential importance of common mycorrhizal networks in managed systems, and provide insight into how these networks could be managed effectively to maximize the functions and outputs from managed systems. We also emphasize possible negative effects of common mycorrhizal networks on plant performance and question popular views that mycorrhizal networks may offer a panacea for enhancing ecosystem services. We highlight the need to gain greater insight into the ubiquity, functioning, and response to management interventions of common mycorrhizal networks and, critically, the need to determine the extent to which these networks can add value to the promotion of mycorrhizal colonization.

Environmental sciences, Botany
DOAJ Open Access 2020
Responses of photosynthetic characteristics and growth in rice and winter wheat to different elevated CO2 concentrations

C. LIU, Z.H. HU, L.F. YU et al.

This study investigated the effects of different elevated CO2 concentrations [ambient CO2 concentration (CK), CK plus 40 μmol mol-1 (T1), CK plus 200 μmol mol-1 (T2)] on photosynthetic characteristics and growth of rice (Oryza sativa L.) and winter wheat (Triticum aestivum L.). The results showed that T2 treatment decreased the net photosynthetic rate and leaf nitrogen content (LNC) but increased the light-saturated net photosynthetic rate of rice. Additionally, T2 treatment increased biomass accumulation and yield in both rice and winter wheat to some extent. T1 treatment, however, had little effect on photosynthetic parameters, LNC, biomass, and yield during the rice and winter wheat growing seasons. The above results suggest that the photosynthesis and growth responses of rice and winter wheat to different CO2 concentrations differed, in general, the increase of CO2 concentrations influenced more photosynthetic performance and growth of C3 plants than lower CO2 concentrations.

DOAJ Open Access 2020
The Potential Biological Agent Bacteria Against for Controling Important Pathogens on Rice

Ratna Sari Dewi, Giyanto Giyanto, Meity Suradji Sinaga et al.

Saat ini teknologi pengendalian hayati penyakit utama padi terus berkembang. Dalam pengembangan teknologi pengendalian hayati, mekanisme penghambatan patogen dalam perkembangan penyakit pada suatu populasi tumbuhan dalam area tertentu menjadi hal yang penting. Penelitian bertujuan mendapatkan bakteri agens hayati potensial dalam pengendalian penyakit penting padi di antaranya yang disebabkan Pyricularia oryzae, Xanthomnas oryzae pv. oryzae, Rhizoctonia solani, Burkholderia glumae, dan Drechlera oryzae, berdasarkan mekanisme antagonisme, kemampuan menginduksi ketahanan dan mendukung kebugaran tanaman, serta kompatibilitas antaragens hayati. Ralstonia pickettii TT47, Pseudomonas fluorescens P12, Chromobacterium sp. T51118, Bacillus subtilis 451 dan 154, serta Streptomyces sp. T51105 dibuktikan memiliki mekanisme antibiosis dengan menghasilkan metabolit sekunder dan senyawa volatil. Berdasarkan uji produksi enzim kitinolitik Chromobacterium sp. dan Streptomyces sp. memiliki mekanisme lisis. Aktivitas antibiotik R. pickettii dan P. fluorescens tergolong kuat terhadap P. oryzae dengan penekanan secara berurutan sebesar 79.68% dan 77.59% pada uji biakan ganda. Penekanan pertumbuhan miselium P. oryzae dan R. solani pada uji volatil mencapai 100% oleh Chromobacterium sp. Semua agens hayati umumnya mampu menginduksi ketahanan dan mendukung kebugaran tanaman. Uji kompatibilitas menunjukan R. pickettii, P. fluorescens, dan Chromobacterium sp. bersifat kompatibel. Dari hasil penelitian diperoleh tiga bakteri agens hayati dengan kategori unggul, yaitu P. fluorescens P12, R. pickettii TT47, dan Chromobacterium sp. T51118. Ketiganya mampu menekan pertumbuhan patogen, menginduksi ketahanan dan mendukung kebugaran tanaman, memiliki patogen sasaran yang lebih beragam, serta bersifat kompatibel.

DOAJ Open Access 2020
Comparative analysis of nitrogen metabolism-related genes in two inbred maize lines with different low-nitrogen tolerance

M. YAN, J. LUO, L. LIANG et al.

Maize is an important crop and its nitrogen use efficiency (NUE) has been an issue for plant scientists and breeders for many years. To meet the demand of genetic diversity in cultivating local elite maize cultivars, researchers need to isolate germplasms with a high NUE. In this study, 30 maize inbred lines were screened under hydroponic conditions, and three inbred lines that tolerate low nitrogen concentration were identified. A comparative analysis of genes involved in N uptake, transport, and assimilation between two lines with different tolerances revealed that the low-nitrogen-tolerant inbred line MBST exhibited higher expressions of nitrate and ammonium transporters, especially ZmNRT3.1B, than less tolerant B73. This suggests that the MBST line had a more efficient high-affinity transporter system. We also showed that low-nitrogen conditions down-regulated the expressions of master genes, ZmNLPs, which were negatively correlated with the expressions of the nitrate transporters ZmNRTs. This indicates the existence of regulators that antagonize the function of ZmNLPs. Some genes related to N assimilation and carbon metabolism were also more expressed in MBST. This research shows that the low-nitrogen-tolerant line, MBST, transported nitrate and ammonium more effectively than the B73 line. The NUE was also higher in MBST than in B73.

Biology (General), Plant ecology
DOAJ Open Access 2020
Assessing farmers’ perception on criteria and indicators for sustainable management of indigenous agroforestry systems in Uttarakhand, India

P.C. Phondani, R.K. Maikhuri, L.S. Rawat et al.

The main objective of this study was to investigate and analyse the farmers’ perceptions on criteria and indicators for sustainable management of indigenous agroforestry systems in Uttarakhand state of India. The present study was conducted to document the traditional knowledge and considered five broad categories including agriculture management, livestock management, forest sustainability, social benefits, and policy inputs along with 16 criteria and 34 indicators were identified. Traditional uses of 48 agroforestry species were documented along an altitudinal gradient from 800 to 1800 ​m above sea level (m asl). Perceptions and responses of 150 farmers of three village clusters located at different agroclimatic zones viz., Saknidhar, Jakhand and Dagar based on their demographic characteristics were documented towards the possible factors for deterioration and viable options for sustainable management of indigenous agroforestry systems. The results of the present study are valuable to local farmers and policy planners to examine the current policies and improved for sustainable energy supply in the Himalayan context through utilization of indigenous agroforestry species. The findings will help to refine and enrich the knowledge among the stakeholders to provide an effective framework for decisions and policy making to sustain and maintain agroforestry strength and services. Keywords: Agroforestry, Farmers’ perception, Traditional knowledge, Criteria and indicators, Himalaya

Environmental sciences
DOAJ Open Access 2019
Growth performance and biochemical profile of Azolla pinnata and Azolla caroliniana grown under greenhouse conditions

Kösesakal Taylan, Yıldız Mustafa

This study aimed to evaluate the growth performance, pigment content changes, essential amino acids (EAAs), fatty acids (FAs), and proximate composition of Azolla pinnata and Azolla caroliniana grown in a greenhouse. Plants were grown in nitrogen-free Hoagland’s solution at 28±2°C/21±2°C, day/night temperature and 60-70% humidity and examined on the 3rd, 5th, 10th and 15th days. The mean percentage of plant growth and relative growth rate for A. pinnata were 119% and 0.148 gg-1day-1, respectively, while for A. caroliniana these values were 94% and 0.120 gg-1day-1, respectively. Compared to day 3, the amount of total chlorophyll obtained on day 15 decreased significantly (p<0.05) for A. pinnata while the total phenolic and flavonoid contents increased significantly (p<0.05) from the 3rd to the 15th day. However, the total phenolic and flavonoid contents did not differ (p>0.0.5) in A. caroliniana. The crude protein, lipid, cellulose, ash values and the amounts of EAAs were higher in A. pinnata than A. caroliniana. Palmitic acid, oleic acid, and lignoceric acid were found to be predominant in A. pinnata and A. caroliniana. From the plant growth and pigment contents, we concluded that A. pinnata grew faster than A. caroliniana and its photosynthetic efficiency was more effective.

Biology (General)
DOAJ Open Access 2019
ارزیابی کارآیی مدل های شبکه عصبی مصنوعی در برآورد عملکرد اسانس گیاه مرزه تابستانه بر اساس ویژگی های زودیافت خاک

حسین صبوری فرد, عظیم قاسم نژاد, خدایار همتی et al.

سابقه و هدف: یکی از نیازهای مهم در برنامه‌ریزی تولید و فرآوری گیاهان دارویی به منظور حصول عملکرد بالا و با کیفیت مطلوب، ارزیابی اولیه خصوصیات فیزیکی و شیمیایی خاک منطقه است که می‌توان با اجتناب از کاربرد غیرضروری آزمایشات متنوع خاکشناسی، هزینه تولید را به حداقل کاهش داد. مرزه تابستانه (Satureja hortensis L) از جمله گیاهان دارویی پرکاربرد است که میزان اسانس و ترکیبات آن شاخص کیفی گیاه محسوب می‌شود. امروزه با ورود مدل‌های رگرسیونی چند متغیره و مدل‌های شبکه مصنوعی در تحقیقات، بسیاری از روابط پیچیده موجود در طبیعت قابل درک است. از این رو ضرورت برآورد عملکرد اسانس گیاه مرزه با استفاده از روش‌های سریع، کم هزینه و با دقتی قابل قبول احساس می‌گردد.مواد و روش‌ها: این پژوهش بصورت طرح کاملاً تصادفی، در سه تکرار و بصورت گلدانی انجام شد. از مناطق مختلف شهرستان نیشابور 53 نمونه خاک تهیه و پارامترهای زودیافت آن که شامل 1-درصد شن، 2-درصد سیلت، 3-درصد رس، 4-مواد آلی، 5-اسیدیته، 6-شوری، 7-فسفر، 8-پتاسیم، 9-نیتروژن، 10-درصد کربن می‌باشد، در آزمایشگاه اندازه‌گیری و نتایج اولیه بدست آمد. تقریباً 90 روز پس از کشت بذور در گلدان‌های حاوی نمونه‌های مختلف خاکی، نمونه‌گیری از آن‌ها صورت گرفت. سپس نمونه‌ها به مدت 24 ساعت در آون 40 درجه سانتی‌گراد قرار گرفتند تا خشک شوند. در نهایت رابطه‌های بین عملکرد اسانس گیاه مرزه و پارامترهای زودیافت خاک با تجزیه شبکه عصبی مصنوعی و با استفاده از نرم افزار Matlab7.9 مشخص گردید. برای بدست آوردن حساس‌ترین پارامترها، تجزیه حساسیت به روش ضریب بدون بعد حساسیت محاسبه گردید. بطوری که اگر مقدار ضریب حساسیت پارامتری از 1/0 بیش‌تر باشد، آن پارامتر جز پارامترهای حساس مدل محسوب ‌شد.یافته‌ها: شبکه عصبی مصنوعی از الگوی شبکه عصبی مصنوعی انسان شبیه‌سازی شده است، به گونه‌ای که می‌تواند پس از آموزش، پارامترهای خروجی مورد نظر را با اعمال پارامترهای ورودی برآورد نماید. در این پژوهش، از ساختار شبکه عصبی پرسپترون با الگوریتم آموزشی مارکوآت لونبرگ استفاده شد تا عملکرد اسانس از پارامترهای زودیافت خاک همچون بافت خاک، مواد آلی و عناصر پرمصرف برآورد شود. بالا بودن مقادیر R2 و پایین بودن مقادیر RMSE یاد شده بیانگر نزدیک بودن داده‌های پیش‌بینی با داده‌های اندازه‌گیری و دقت بالای مدل در برآورد عملکرد اسانس گیاه مرزه تابستانه است. بر این اساس پارامترهای بافت خاک(درصد شن، سیلت و رس) و کربن آلی، ماده آلی، شوری، پتاسیم و اسیدیته خاک به ترتیب به عنوان حساس‌ترین پارامترها انتخاب گردید. نتیجه‌گیری: نتایج نشان داد که مدل‌های عصبی ایجاد شده قادر نبودند عملکرد اسانس در گیاه مرزه تابستانه را با حداکثر دقت (R2= 0.50) برآورد نمایند. از بین 8 مدل برازش یافته یک مدل مبتنی بر متغیرهای مستقل EC + بافت + کربن + ماده آلی + پتاسیم + pH عملکرد بهتری داشت، با این وجود تعداد بالای عوامل ورودی این مدل محدودیت تلقی می‌شود. از آنجایی که این تحقیق جزء اولین بررسی‌ها در مورد برآورد عملکرد اسانس گیاهان دارویی بود، لذا ادامه تحقیق و بررسی در این خصوص و همچنین پیش‌بینی عملکرد سایر گیاهان دارویی به این روش پیشنهاد می‌گردد.

Plant ecology
DOAJ Open Access 2016
Phytotoxic Activity of Parthenium Against Wheat and Canola Differ With Plant Parts and Bioassays Techniques

A. KHALIQ, F ASLAM, A MATLOOB et al.

Phytotoxic effects of invasive weed Parthenium hysterophorus were studied by using whole plant, leaf and root aqueous extracts at 0, 2.5, 5.0, 7.5 and 10% (w/v) concentrations against germination and early seedling growth of wheat and canola. Studies were carried out both in Petri plates with filter paper as substratum placed in controlled conditions and soil-filled plastic pots placed in open environments. Pronounced variation was noted for phytotoxic activity of different plant parts of parthenium, aqueous extract concentrations, test species, and bioassay techniques. Aqueous parthenium extracts either inhibited or delayed the germination and suppressed seedling growth of test species over control. For both test species, all the germination attributes were suppressed to a greater extent in Petri plates than in plastic pots. Leaf extracts were more suppressive to germination of test species than whole plant and root extracts. Increasing extract concentration beyond 2.5% caused significant reduction in seedling dry biomass of both test species. Aqueous parthenium extract diminished chlorophyll contents of wheat and canola by 32-63% and 29 69%, respectively. Nevertheless, an increase of 9-172% and 22-60% in phenolic contents of wheat and canola was recorded. Canola appeared to be more susceptible than wheat at all extract concentrations. Present study concluded that bioassays conducted under controlled condition using filter paper as substratum may be misleading due to over estimation of allelopathic response and variation in potential of receiver and donor species. Furthermore, it implies that threshold concentrations of allelochemicals for test species in Petri plates are rarely reached under field conditions.

Biology (General), Botany
DOAJ Open Access 2015
Conceptions of Landscape-Ecological Relevance Emerged in the Czech Botany during the Second Half of Twentieth Century

Kovář Pavel

This paper summarizes those substantial theoretical concepts or methods for applications within interdisciplinary or practical uses published by Czech autors (geobotanists = ecological botanists, plant ecologists and ecophysiologists) during the second half of the 20th century, that were internationally cited. All selected thematical clusters are of landscape-ecological relevance through various contexts. Examples include the concepts of (potential) reconstructed vegetation in maps (R. Neuhäusl, Z. Neuhäuslová), linear vegetation features (corridors in landscape) and deductive classification of vegetation (K. Kopecký), analysis of soil seed bank (Z. Kropáč), dependency of macrophyte plant stands on ecodynamics (S. Hejný), dynamic periodicity in segetal vegetation (Z. Kropáč, E. Hadač, S. Hejný), anemo-orographic system explaining species richness in mountain regions (J. Jeník), productivity in grassland ecosystems (M. Rychnovská, J. Květ), elementary landscape units based on homogenity and potential vegetation (E. Hadač), landscape dispensation phenomena (V. Ložek), afforestation of coastal sandy dunes – the Netherlands, and polluted areas - the Czech Republic (J. Fanta), invasive plants and invasions into landscapes (M. Rejmánek).

DOAJ Open Access 2014
Precisiones nomenclaturales en Phlomis × composita Pau (Lamiaceae)

P. P. Ferrer-Gallego, M. Guara, E. Laguna

Se revisan algunos aspectos relacionados con la nomenclatura de Phlomis × composita. Se tipifica el nombre P. × composita Pau (Lamiaceae) a partir de material original de Pau, recolectado por Bourgeau en 1849 y conservado en el herbario del Real Jardín Botánico de Madrid. Se rechaza la anterior propuesta de tipificación de Mateu (1986) por ser incorrecta. Se propone un nuevo estatus taxonómico para el híbrido entre P. crinita subsp. crinita y P. lychnitis, bajo el rango de notosubespecie: P. × composita nothosubsp. trullenquei (Pau) P. P. Ferrer, Guara & E. Laguna, stat. nov.

Biology (General), Botany
DOAJ Open Access 2014
Flavonoids from the flowers of Nymphaea alba L.

Jerzy Jambor, Lutosława Skrzypczak

Ten flavonoids were obtained from the flowers of Nymphaea alba L. Their structures were determined mainly on the basis of spectral analyses (UV, 'H NMR, MS). The following aglycons were isolated: quercetin, kaempferol, isokaempferide and apigenin as well as the following glycosides: quercetion 4'-β-xyloside, 3-methylquercetin 3'-β-xyloside and a mixture of quercetin 3-galactoside and 3-glucoside. The structures of three compounds obtained in very small amounts were determined in part.

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