Caragana Arborescens Research Articles

Structure and biogenesis of ribonucleoprotein bodies in epidermal cells of Caragana arborescens L.

Epidermal cells of leaf petioles, pedicles, and sepals in Caragana arborescens L. are characterized with a unique biogenesis of intracellular bodies, the presence of which continues during 10-12days in spring, from budding till flowering and fruit inception. Initially, a nuclear body is formed as a derivative of the nucleolus at the beginning of elongation of the protodermal cells, whereas a cytoplasmic body is formed in the proximity of the nuclear envelope later. Nuclear bodies and cytoplasmic bodies do not contain DNA, lipids, and starch, and they consist of RNA tightly packaged with proteins mainly in the form of short thin fibrils with thickness of 6nm. By the end of cell elongation and the beginning of differentiation, nuclear bodies disappear, while cytoplasmic bodies become surrounded by a homogenous zone (halo). Later, the bundles of parallel-oriented fibrils derived from the body radially pass through the homogenous zone and gradually disperse in the cytoplasm. In the differentiated epidermal cells, no traces of cytoplasmic bodies are observed; there is only one nucleolus in the nucleus. It is hypothesized that cytoplasmic bodies may function as an RNA depot, which is utilized later in cell metabolism during the formation of fruits and seeds.

Alien plants in forest communities of the Middle Volga Region: dissemination and degree of naturalization

In forest communities of the Middle Volga forest-steppe zone (within Penza, Samara and Ulyanovsk Regions) there are 60 alien species of vascular plants. 25 species of adventives (42%) have naturalized in forests, 7 species are epecophytes (Cotoneaster lucidus , Oenothera biennis, O. rubricaulis, and O. villosa, Populus suaveolens, Ulmus minor, Xanthoxalis stricta) and 18 species are agriophytes (Acer negundo, Amelanchier spicata, Bidens frondosa, Caragana arborescens, Conyza canadensis, Echinocystis lobata, Heracleum sosnowskyi, Impatiens parviflora, Fraxinus lanceolata, F. pennsylvanica, Lonicera tatarica, Lupinus polyphyllus, Malus domestica, Parthenocissus inserta, Salix euxina, Sambucus racemosa, S. sibirica, Ulmus pumila). Transformer-types are arboreal - Acer negundo, Fraxinus lanceolata, F. pennsylvanica, Parthenocissus inserta, Ulmus pumila, as well as herbaceous plants - Bidens frondosa, Conyza canadensis, Echinocystis lobata, Heracleum sosnowskyi, Impatiens parviflora. The introduction of alien trees and shrubs in the forest can lead to dense thickets, disrupt underbrush resumption and main forest-forming species growth, as well as negatively affect the herbaceous layer. Most vulnerable to the introduction of adventive plants are roadsides and the places where forests are close to human settlements. The introduction of alien plants in forest communities is the result of ornithochory (33; 54%), anemochory (11 species; 18%), anthropochory (8 species; 13%) or a combination of various ways of introduction.

Vascular bundle connection between seed stalk and seed coat of Caragana arborescens

The purpose of this study was to investigate the morphology, transmission route of photosynthetic products in the seed stalk of Caragana arborescens Lam. at various stages after flowering and evaluate the role of the seed stalk in seed maturation using scanning electron microscopy. We found that the mature seed stalk mainly consisted of vessels, sclerenchymatous cells and parenchymatous cells. Elongated cells formed a ring at the junction between the seed stalk and seed, and a large hollow was produced by two layers of sclerenchymatous cells in the interior seed, which functions to sustain seed growth. The opening in the center of the ring was closed during an early stage of seed development, and the opening enlarged as the seed matured. There were two routes for material transport, which started from the seed stalk: one from the seed coat to the embryo, and another directly entering the embryo. Vessels, which are abundant in the seed stalk, are the pathway for absorption of nutrients by the seeds. The vessels were densely packed in the seed stalk, and secondary thickening of the cell wall of the vessels was characterized by net thread thickening, while the secondary thickening of the cell wall of the vessels within the seed was characterized by screw thread thickening. The morphological characteristics of the vessels were adaptive to its functions.

Sorafenib induced alteration of protein glycosylation in hepatocellular carcinoma cells.

Sorafenib is a multikinase inhibitor and is effective in treating hepatocellular carcinoma (HCC). However, it remains unknown whether sorafenib induces the alteration of protein glycosylation. The present study treated HCC MHCC97L and MHCC97H cells with a 50% inhibitory concentration of sorafenib. Following this treatment, alteration of protein glycosylation was detected using a lectin microarray. Compared with the controls, the binding capacity of glycoproteins extracted from sorafenib-treated HCC cells to the lectins Bauhinia purpurea lectin, Dolichos biflorus agglutinin, Euonymus europaeus lectin, Helix aspersa lectin, Helix pomatia lectin, Jacalin, Maclura pomifera lectin and Vicia villosa lectin were enhanced; while, the binding capacities to the lectins Caragana arborescens lectin, Lycopersicon esculentum lectin, Limulus polyphemus lectin, Maackia amurensis lecin I, Phaseolus vulgaris leucoagglutinin, Ricinus communis agglutinin 60, Sambucus nigra lectin and Solanum tuberosum lectin were reduced (spot intensity median/background intensity median ≥2, P<0.05). This difference in glycoprotein binding capacity indicates that cells treated with sorafenib could increase α-1,3GalNAc/Gal, β-1,3 Gal, GalNAcα-Ser/Thr(Tn) and α-GalNAc structures and decrease GlcNAc, sialic acid, tetra-antennary complex-type N-glycan and β-1,4Gal structures. These results were additionally confirmed by lectin blotting. Expression levels of signaling molecules including erythroblastosis 26–1 (Ets-1), extracellular signal-related kinases (ERK) and phosphorylated-ERK were measured by western blotting. There was a reduction in the expression of Ets-1 and ERK phosphorylation in sorafenib or 1,4-Diamino-2,3-dicyano-1,4-bis (2-aminophenylthio) butadiene treated cells suggesting that sorafenib may reduce the expression levels of Ets-1 by blocking the Ras/Raf/mitogen activated protein kinase signaling pathway. In the present study, it was clear that sorafenib could inhibit the proliferation of HCC cells and alter protein glycosylation. The findings of this study may lead to providing a novel way of designing new anti-HCC drugs.

Soil organic carbon sequestration by shelterbelt agroforestry systems in Saskatchewan

Carbon (C) sequestration through the implementation of agroforestry practices is identified as one of the major strategies in the reduction of carbon dioxide (CO2) emissions from the agricultural sector. The objective of this study was to examine the soil organic carbon (SOC) sequestration potential of major shelterbelt species, including green ash (Fraxinus pennsylvanica), hybrid poplar (Populus spp.), Manitoba maple (Acer negundo), white spruce (Picea glauca), Scots pine (Pinus sylvestris), and caragana (Caragana arborescens), ranging in age from 5 to 63 yr. Soil samples (0–50 cm) were collected for six major shelterbelt species and adjacent agricultural fields, and SOC concentration was determined. Shelterbelts had a significantly higher amount of SOC compared with adjacent agricultural fields, with an average difference of 18.6 Mg C ha−1 in the top 50 cm soil. An additional 3–8 Mg C ha−1 was contained in the tree litter layer. Younger shelterbelts (age less than 20 yr) tended to lose SOC in the early ...

Reassessment of Allantonectria, phylogenetic position of Thyronectroidea, and Thyronectria caraganae sp. nov.

The genus Allantonectria is synonymised with Thyronectria, based on morphological and molecular phylogenetic considerations. Investigations of types and fresh collections revealed that Tubercularia concentrica is an earlier name for Sphaeria (syn. Allantonectria) miltina and is thus combined in Thyronectria. Allantonectria yuccae is recognised as a distinct species and transferred to Thyronectria, as well as the recently described A. zangii. Descriptions and illustrations are provided for T. concentrica and T. yuccae. A recent collection of the North American Thyronectroidea chrysogramma, the generic type of Thyronectroidea, was studied with respect to morphology of its sexual morph in fresh condition and of its asexual morph produced in pure culture. Molecular phylogenies based on six loci (ITS and LSU regions of nuc rDNA, act1, rpb1, rpb2, tef1 and tub2 genes) place T. chrysogramma within Thyronectria, confirming synonymy of Thyronectroidea with Thyronectria, but remarkably a relationship to European species with green to brown spores (former genus Mattirolia) receives no support, and its closest relatives remain unclear. Thyronectria caraganae is described as a new species from herbarium specimens of Caragana arborescens collected in the Ukraine. It is characterised by morphology of the sexual morph and by DNA sequence data, which place it within the T. austroamericana - T. rhodochlora clade with high support. This is also supported by its morphology, specifically ascomata partly embedded within a stroma, muriform ascospores not budding within the ascus, becoming yellowish to rosy at maturity.

Systematics and biology of some species of Micrurapteryx Spuler (Lepidoptera, Gracillariidae) from the Holarctic Region, with re-description of M. caraganella (Hering) from Siberia.

During a DNA barcoding campaign of leaf-mining insects from Siberia, a genetically divergent lineage of a gracillariid belonging to the genus Micrurapteryx was discovered, whose larvae developed on Caragana Fabr. and Medicago L. (Fabaceae). Specimens from Siberia showed similar external morphology to the Palearctic Micrurapteryx gradatella and the Nearctic Parectopa occulta but differed in male genitalia, DNA barcodes, and nuclear genes histone H3 and 28S. Members of this lineage are re-described here as Micrurapteryx caraganella (Hering, 1957), comb. n., an available name published with only a brief description of its larva and leaf mine. Micrurapteryx caraganella is widely distributed throughout Siberia, from Tyumen oblast in the West to Transbaikalia in the East. Occasionally it may severely affect its main host, Caragana arborescens Lam. This species has been confused in the past with Micrurapteryx gradatella in Siberia, but field observations confirm that Micrurapteryx gradatella exists in Siberia and is sympatric with Micrurapteryx caraganella, at least in the Krasnoyarsk region, where it feeds on different host plants (Vicia amoena Fisch. and Vicia sp.).In addition, based on both morphological and molecular evidence as well as examination of type specimens, the North American Parectopa occulta Braun, 1922 and Parectopa albicostella Braun, 1925 are transferred to Micrurapteryx as Micrurapteryx occulta (Braun, 1922), comb. n. with albicostella as its junior synonym (syn. n.). Characters used to distinguish Micrurapteryx from Parectopa are presented and illustrated. These findings provide another example of the potential of DNA barcoding to reveal overlooked species and illuminate nomenclatural problems.

Bio-Morphological Characters of Alien Legume Species, Influencing Their Invasion in Natural Plant Communities

Five alien legume species, actively invading in natural plant communities in European part of Russia, were studied—Lupinus polyphyllus Lindl., Galega orientalis Lam., Robinia pseudoacacia L., Amorpha fruticosa L. and Caragana arborescens L. Distribution ranges (considering their invasive status) were mapped. Not a single bio-morphological character to forecast invasion success in natural plant communities within secondary distribution range was found. The data of key value/importance for explaining invasive success of the species studied were obtained. Two hypotheses— Propagule Pressure and Evolution of Invasiveness—were critically analyzed in view of the received data.

Resistance of soybean collection specimens to hazardous organisms

The study presents results of studying resistance of 205 soybean collection specimens originating from 21 countries to a range of hazardous organism on artificial background of Fusarium and provocative backgrounds of bacteriosis and lima-bean pod borer in the eastern Forest-Steppe of Ukraine in 2009-2014.The aim and tasks of the study. Search for new sources of resistance to pests and diseases is very important for soybean breeding. The study aim was to identify new genetic sources of soybean resistance to Fusarium, bacteriosis, and lima-bean pod borer for further use in soybean breeding.Material and Methods. The field studies were carried out in scientific rotation of the Plant Production Institute named after Yuriev V. Ya. of NAAS in an infectious nursery for pulses. Sowing and monitoring was conducted according to standard techniques using phytopathological, entomological and mycological research methods. Fusarium artificial infectious background was created by inoculating oat grain infected with Fusarium spp. agents simultaneously with soybean sowing in the amount of 100-150 g / m2. Provocative background of lima-bean pod borer was created by planting the test soybean collection specimens next to the Siberian pea shrub plantation, which is a reservoir of this pest.Results and Discussion. The three-year studies identified soybean sources of individual, group and complex resistance to the diseases and pest. During the study period we selected 28 sources of individual resistance, of which eight are resistant to Fusarium and 20 - to bacteriosis. Twelve specimens with group resistance to Fusarium and bacteriosis were identified. Two specimens had complex resistance.Conclusions. Over the six-year study period (2009-2014) we selected 42 new sources of soybean resistance to the diseases and pest, which are valuable source material and recommended for use in soybean breeding to create resistant varieties.

About Flowering Biology of Alien Species: 3. Caragana arborescens Lam. and C. laeta Kom.

Some data on flowering biology of a potentially aggressive alien species—Caragana arborescens—are presented. Micromorphological characters of flowers at different stages of development for typical plants and two cultivars (C. arborescens f. pendula and C. arborescens f. lorbergii) and also for the Central Asian C. laeta are described. The pollen fertility is defined. A number of features in which C. arborescens has a competitive superiority over closely related taxa are revealed. Arguments for C. arborescens f. lorbergii allocation as a particular taxon are adduced.

Oleanane Triterpenoid Saponins of Caragana arborescens and Their Quantitative Determination

Seed extracts of common Caragana (Caragana arborescens), belonging to the pea family (Fabaceae), were prepared by Diaion HP-20 resin technology and examined for the presence of triterpenoid saponins by a combination of chromatographic, spectroscopic and spectrometric techniques. Electrospray LC-MS on the extracts indicated the presence of soyasaponin I (1a), soyasaponin VI (soyasaponin βg,1b) possessing a 2,3-dihydro-2,5-dihydroxy-6-methyl-4 H-pyran-4-one (DDMP) group, 22-propionylsoyasaponin I (1c), soyasaponin III (2a), the DDMP conjugate of soyasaponin III (2b) and 22-propionylsoyasaponin III (2c). Alkaline hydrolysis conditions were employed to convert the C-22 conjugates to soyasaponin I (and soyasaponin III), utilizing sodium hydroxide in ethanol and HPLC with an evaporative light scattering detector and internal standard. A quantitative method based on high performance liquid chromatography-tandem mass spectrometry (LC–MS/MS) with digoxin as internal standard was developed to determine 1a in the extracts. After hydrolysis and C18 SepPak clean-up with aqueous ethanol as solvent, seeds of Caragana collected over 3 years gave 1a concentrations of 1041–1563mg/kg of hexane-defatted flour.

FLORA OF THE IVANOVO REGION FARMSTEAD PARK “GRIDINO”

Data about flora of Ivanovo old region farmstead park Gridino are presented. Park and reservoir belong to Ivanovo region special protected territories-natural monument. Historical information about manufacturer farmstead of M.A. Pavlov and park planning are briefly reported. Modern park flora consists of 270 vascular plant species from 5 classis, 94 families and 146 genera. Asteraceae-32 species (11,9%), Rosaceae-29 species (10,7%), Poaceae-24 species (8,9%) are leading families of the park flora. 1 species (Agrimonia pilosa) included in to Convention on the Conservation of European Wildlife, 3 rare species (Abies sinirica, Cornus alda, Deschampsia flexuosa)-in to regional Red date book are characterized. Some decorative arboreal (woody) species (Thuja occidentalis, Larix sibirica, Alnus incana forma pinnati - fida, Populus alba, Caragana arborescens, Crataegus sanguine and other) species and grassy introduced plants (Hieracium murorum, Myosotis sylvatica, Phyteuma spicatum and other) are described. Examples of alien plant species spreading on territory of the park are given. Events for green plantations improvement are listed. Farmstead park Gridino is important object for regional biological diversity conservation and rare plan protection. Large recreational, educational and informa - tive functions of the park are shown.

Mapping and quantification of planted tree and shrub shelterbelts in Saskatchewan, Canada

The Government of Canada’s farm assistance programs have affected >80 % of Canada’s agricultural land base. One important program in the Prairie Provinces was the prairie shelterbelt program (PSP). A significant aspect of the PSP was shelterbelt tree planting to protect farmyard infrastructure and reduce soil erosion. The main goal of this paper was to map historical shelterbelt establishment, total expected shelterbelt length, and total expected number of six common planted shelterbelt species: caragana (Caragana arborescens), green ash (Fraxinus pennsylvanica), Manitoba maple (Acer negundo), Scots pine (Pinus sylvestris), white spruce (Picea glauca Monch), and hybrid poplar (Populus spp.). A clustering approach was designed to group all agricultural ecodistricts (106 total) into clusters (31 total) based on their similarity in 42 variables within five soil zones of Saskatchewan. Correlations between trees ordered through the PSP and observed shelterbelt length (across 2.1 Mha cumulative study area) were used for shelterbelt probability mapping. Mapping accuracy of planted shelterbelts was 48–86 %. Total shelterbelt length (of any species) ranged from 322 to 45,231 km for (in descending order) dark brown > brown > black > dark gray > gray soil zones. Novel decadal time-lapse maps and species-specific shelterbelt maps were produced to capture the progression of shelterbelt establishment for the first time at a province-wide scale which gave a new perspective, in map format, of the expansive impact of the living legacy of the PSP. Shelterbelt data gaps and high priority clusters of agricultural land in Saskatchewan were identified for future shelterbelt research.

Ultrastructure of cleistothecia and the stages of life cycle of Microsphaera palczewskii by scanning electron microscope

Several year long investigations of the developmental cycle of &lt;i&gt;Microsphaera palczewskii&lt;/i&gt; occurring on the leaves of &lt;i&gt;Caragana arborescens&lt;/i&gt; in Central Poland are reported. The material was studied with light and scanning electron microscopes. The scanning microscopy micrographs of the clistothecia and appendages presented in this report are the first micrographs of this species.

Quantifying biological nitrogen fixation of agroforestry shrub species using 15N dilution techniques under greenhouse conditions

Some land-use systems in Saskatchewan, Canada include the nitrogen-fixing trees buffaloberry (Shepherdia argentea Nutt.), caragana (Caragana arborescens Lam.) and sea buckthorn (Hippophae rhamnoides L.). These species provide various ecological functions such as ameliorating soil moisture, light and temperature but little work has been done quantifying biological nitrogen fixation by these species. Greenhouse experiments were conducted to quantify N2-fixation using the 15N natural abundance and the 15N dilution methods. Buffaloberry failed to form nodules in all but one of the four replicates in the natural abundance experiment. Using the 15N dilution method, the percentage of N derived from atmosphere (%Ndfa) in the shoot of buffaloberry averaged 64 %. For caragana, the mean %Ndfa was 59 and 65 % and seabuckthorn was 70 and 73 % measured using the natural abundance and dilution methods, respectively. Because of large variability in biomass production between plants grown in the natural abundance experiment and the dilution experiment, the amounts of N2 fixed also were very variable. Buffaloberry fixed an average of 0.89 g N m−2; the average for caragana ranged from 1.14 to 4.12 g N m−2 and seabuckthorn ranged from 0.85 to 3.77 g N m−2 in the natural abundance and dilution experiments, respectively. This corresponds to 16 kg N ha−1 year−1 for buffaloberry; an average of 15–73 kg N ha−1 year−1 in caragana and 11–67 kg N ha−1 year−1 in seabuckthorn. The substantial amounts of N2 fixed by these species indicate that they have the potential to contribute to the overall N balance in land-use systems in which they are included.

Flowering of siberian peashrub (Caragana arborescens Lam.) and its forage value to pollinating insects

&lt;p class="abstracttekst"&gt;Under the conditions of Lublin (central-eastern Poland), observations were conducted on the flowering of &lt;em&gt;Caragana arborescens &lt;/em&gt;shrubs for two growth seasons as well as nectar and pollen production by the flowers of this species was investigated.&lt;/p&gt;&lt;p class="abstracttekst"&gt;The flowering period of &lt;em&gt;Caragana arborescens &lt;/em&gt;began at the turn of April and May and lasted for 24 days, while for a single flower it was 6.30 ± 0.79 days. The average weight of nectar, sugars and pollen produced by 10 Siberian peashrub flowers was, respectively: 46.70 ± 8.39 mg, 22.79 ± 6.10 mg, and 4.45 ± 0.34 mg. The nectar sugar concentration amounted 49.60 ± 10.08%. Pollen grains reached average dimensions of 21.94 ± 0.76 µm x 21.52 ± 0.71 µm. During a growing season, one &lt;em&gt;Caragana arborescens&lt;/em&gt; shrub can provide on average 101.8 g of nectar, 49.7 g of sugars, and 9.7 g of pollen.&lt;/p&gt;

干旱胁迫对青藏高原6种植物生理指标的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 干旱胁迫对青藏高原6种植物生理指标的影响 DOI: 10.5846/stxb201306031288 作者: 作者单位: 华南农业大学,华南农业大学,华南农业大学,中国林业科学研究研究院林业研究所 国家林业局林木培育重点实验室 北京,华南农业大学,华南农业大学,甘肃省小陇山林业科学研究所 甘肃天水,甘肃省小陇山林业科学研究所 甘肃天水 作者简介: 通讯作者: 中图分类号: 基金项目: 林业公益性行业科研专项（200904033）；科学技术部农业科技成果转化资金项目（2011GB24320010） Physiological indexes of six plant species from the tibetan plateau under drought stress Author: Affiliation: South China Agricultural University,,South China Agricultural University,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以青藏高原6种植物：红花岩黄芪（Hedysarum multijugum Maxim.）、西北沼委陵菜（Comarum salesovianum （Steph.）Asch. et Graebn.）、鲜黄小檗（Berberis diaphana Maxim.）、鲜卑花（Sibiraea laevigata （Linn.）Maxim.）、树锦鸡儿（Caragana arborescens（Amm.）Lam.）、砂生槐（Sophora moorcroftiana（Benth.）Baker）为试材进行干旱胁迫模拟盆栽试验，通过对比6种植物叶片中丙二醛（MDA）、脯氨酸、可溶性蛋白质、叶绿素、可溶性糖、淀粉含量的变化，对供选植物进行抗旱性能分析与评价，为在青藏高原地区筛选优良耐旱植物提供参考依据。设置土壤含水量占田间持水量80%以上为正常水平，50%-70%为轻度干旱，30%-50%为中度干旱，低于30%为重度干旱。研究表明，6种供试植物叶片MDA含量逐渐升高，当土壤含水量占田间持水量12%左右时达到最大值，树锦鸡儿的增幅较另5种苗木最小，而峰值最大。脯氨酸含量都呈增加趋势，其中砂生槐最高，为9981.67 mg/g，峰值与对照值相比，砂生槐增加最多为37.43 倍，鲜卑花最小为0.49 倍。苗木叶片中可溶性蛋白质含量总体表现出现增大后减小的规律，且所有测定值都高于正常水分条件下的含量。6种苗木的叶绿素含量在干旱胁迫下总体呈现先降低再升高最后再降低的趋势，24 d时均低于对照值，下降最多的为西北沼委陵菜（15.43 mg/g）。由于干旱下苗木的光合产物转化受抑，以淀粉形式的累积量减少，所以6种苗木的可溶性糖含量呈上升趋势，而淀粉含量呈下降趋势，通过积累可溶性糖以提高细胞的渗透调节能力。砂生槐、树锦鸡儿的可溶性糖含量增幅与淀粉含量的减少明显高于其余苗木，使其在较低叶水势下仍保持较高的细胞膨压，以减缓水分胁迫的不利影响。主成分分析表明，6种苗木抗旱性由强到弱依次为：树锦鸡儿、红花岩黄芪、砂生槐、鲜黄小檗、鲜卑花、西北沼委陵菜。 Abstract:During adaptation to the environment, plants can gradually develop drought resistance via a process of natural selection. Plants are often under water stress in the cold and dry environmental conditions on the Tibetan Plateau, and these conditions can directly affect various physiological activities. The aim of this study was to analyze and evaluate the drought resistance of selected plants from the Tibetan Plateau, and to provide a reference for selecting drought-tolerant plants. We collected six species of plants from the Tibetan Plateau; Hedysarum multijugum Maxim, Comarum salesovianum (Steph.) Asch. et Graebn., Berberis diaphana Maxim., Sibiraea laevigata (Linn.) Maxim., Caragana arborescens (Amm.) Lam. and Sophora moorcroftiana Benth Baker. To protect themselves against drought and low-temperature stress, plants have evolved efficient antioxidant systems to scavenge reactive oxygen species. We evaluated changes in the amounts of malondialdehyde (MDA), proline, soluble protein, chlorophyll, soluble sugars, and starch in leaves of these species subjected to increasingly severe drought conditions in a pot experiment. The soil moisture was greater than 80% of field capacity for the normal level, 50%-70% for mild drought, 30%-50% for moderate drought, and less than 30% for severe drought. In all six plant species, the MDA content increased slowly from day 0 to day 12 of the drought treatment, and then increased significantly after day 16 to reach a peak when the soil water content was approximately 12%. Caragana arborescens showed the smallest increase in MDA content under drought, but had the highest MDA content (4.72 mmol/g) among the six plant species. The proline content increased in all six species under drought, and there were significant differences among species in the amount of proline accumulated. The largest increase in proline content was in S. moorcroftiana (peak value, 9981.67 mg/g; 37.43 times that in CK), and the smallest was in S. laevigata (peak value was 0.49 times that in CK). The leaf soluble protein content increased under drought conditions in all six species, but began to decrease when the drought conditions became more severe. The largest decrease in protein content under severe drought conditions was in S. moorcroftiana (a decrease of 39.22%, compared with the peak protein concentration). The chlorophyll concentrations in the leaves of the six species first increased and then decreased as the drought conditions became more severe. In the moderate drought period, the chlorophyll content of seedling leaves began to recover, probably because of a decrease in leaf water content. In all six species, the chlorophyll content on day 24 of the drought was lower than that on day 0. The largest decrease in chlorophyll concentration was in C. salesovianum (15.43 mg/g). The soluble starch contents in all six species decreased under drought because of a reduction in photosynthesis; however, all species showed an increase in soluble sugars content, which improved the osmotic adjustment capability of cells. The largest increases in soluble sugars contents and the largest reductions in starch contents were in S. moorcroftiana and C. arborescens. These species were able to retain higher cell turgor pressure at lower water potential, compared with the other species. After day 16 of the drought treatment, the decreases in starch and soluble sugar contents in the leaves indicated that prolonged water stress caused decomposition of biomass, reduced biosynthesis, and a weaker ability for osmotic adjustment. The drought resistance of plants is the sum of many physiological factors, and represents complex interactions among these factors. Thus, it is a complicated physiological adjustment mechanism. The six species were ranked differently in terms of each of the physiological indexes measured. Therefore, we used principal component analysis to select the most important physiological indexes of drought resistance: chlorophyll, MDA, and starch contents. The results of the principal component analysis indicated that species could be ranked, in terms of most to least drought resistant, as follows: C. arborescens > H. multijugum > S. moorcroftiana > B. diaphana > S. laevigata > C. salesovianum. 参考文献 相似文献 引证文献

Morphological traits and physiological characteristics in drought tolerance in 20 shrub species on the Qinghai-Xizang Plateau

Aims Providing indispensably theoretical evidence for establishing indices of evaluation on drought tolerance in shrubs, and screening for tree species that are drought tolerant for afforestation in arid regions or for matching their characteristics with suitable habitat conditions are the key to vegetation restoration in the Qinghai-Xizang Plateau. However, these issues are not adequately addressed in recent research due to lack of systematic methods. Therefore, our objective was to make a comprehensive evaluation on drought tolerance in 20 shrub species collected from different areas in Qinghai-Xizang Plateau, and to study their underlying mechanisms in drought tolerance. Methods We made measurements on variables depicting root characteristics, including the root length(TRL), surface area(TRSA), volume(TRV), and tips number(TRTN) of all roots, the root length(FRL), surface area(FRSA), volume(FRV), and tips number(FRTN) of fine roots(d ≤2 mm), and derived plant characteristic indices including thickness of cuticle(CT), thickness of palisade tissue(TPT), thickness of spongy tissue(TST), TPT/TST, thickness of leaf(LT), palisable tissue cell density, and tissue structural tense ratio(CTR = TPT/LT × 100%) and spongy tissue loosened ratio(SR = TST/LT × 100%) of leaf anatomical structure, root to shoot ratio(RSR), leaf transpiration rate(Tr), instantaneous water use efficiency(WUEi), and carbon isotopic composition(δ13C) of the20 shrub species through field experiments. Correlation analysis and principal component analysis were performed on the 19 variables and indices. Important findings Different shrubs had different mechanisms of drought tolerance. In this study, the characteristics of drought tolerance were mainly categorized into 6 types, involving modifications of(1) root systems,(2) leaf anatomical structure,(3) leaf pattern, and(4) biomass allocation, or via(5) low water-consumption and(6) high WUEi. Different genera or different tree species within the same genus clearly differed in drought tolerance. The species of the genus Hippophae were relatively poorly tolerant to drought, whereas several shrubs including Potentilla fruticosa, Berberis julianae, Caragana arborescens, Spiraea salicifolia and Hippophae rhamnoides ssp. mongolica occurred to be more drought tolerant than other shrub species investigated in this study. On the other hand, there were highly significant correlations among the characteristics of root systems and among characteristics of leaf anatomical structure. The results of principal component analysis on 19 variables and indices showed that TRL, TRSA, TRV, TRTN, FRL, FRSA, FRV, FRTN, CT, TPT, TST and WUEi could be effective indicators of drought tolerance of shrubs in the Qinghai-Xizang Plateau. In addition, the drought tolerance of shrubs had a close connection with their origin of collections; the shrubs collected from Xining prefecture in Qinghai Province were more drought tolerant than those from Tianshui Prefecture in Gansu and Lasa Prefecture in Xizang.

Chemical Investigation of Caragana arborescens Shoots

Phytochemical study of flowering shoots of Caragana arborescens Lam. (Fabaceae family) collected in Buryatia Republic (Russian Federation) resulted in the isolation of twenty compounds identified as quercetin, isoquercitrin and rutin, previously identified in this species, and β-sitosterol, β-sitosterol-3- O-glucoside, umbelliferone, kaempferol, formononetin, isorhamnetin-3- O-glucoside, nicotiflorin, narcissin, myricetin-3- O-rutinoside, ononin, formononetin-7- O-rutinoside, caffeic, 3- O-caffeoylquinic, 5- O-caffeoylquinic, 3,5-di- O-caffeoylquinic acids and sucrose, isolated for the first time from C. arborescens.

Characterization and genus identification of rhizobial symbionts from Caragana arborescens in western Canada

Naturally occurring nitrogen-fixing symbionts from root nodules of caragana (Caragana arborescens) growing in central Saskatchewan were isolated following surface sterilization of caragana root nodules and squashing and spreading of the contents on yeast extract - mannitol medium. The symbiotic nature of the strains was confirmed following inoculation onto surface-sterilized C. arborescens seed in a gnotobiotic Leonard jar system. The Rhizobium isolates from C. arborescens root nodules were intermediate in generation time (g) (mean g of 5 isolates was 6.41 h) compared with the fast growers, Rhizobium leguminosarum NRG457 (g: 4.44 h), Rhizobium tropici 899 (g: 3.19 h), and Sinorhizobium meliloti BALSAC (g: 3.45 h), but they were faster than the slow-growing Bradyrhizobium japonicum USDA 110 (g: 13.86 h) and similar to Mesorhizobium amorphae (g: 7.76 h). Nitrogen derived from fixation by measuring changes in δ(15)N natural abundance in plant tissue confirmed the effectiveness of the strains; approximately 80% N2 from fixation. Strain identification was carried out by determining the sequences of 3 genes: 16S rRNA-encoding genes, cpn60, and recA. This analysis determined that the symbiotic partner of Canadian C. arborescens belongs to the genus Mesorhizobium and seems more related to M. loti than to previously described caragana symbionts like M. caraganae. This is the first report of Mesorhizobium sp. nodulating C. arborescens in western Canada.