Genetic variability of spiralling whitefly Aleurodicus disperses Russell on Citrus aurantifolia Christm and Ocimum gratissimum L.

2021 ◽  
Vol 20 (2) ◽  
pp. 87-98
Author(s):  
Mistura Temitope Adeleke ◽  
Oladunni Nimota Adekunle ◽  
Roseline Tolulope Feyisola ◽  
Folarin Ojo Owagboriaye ◽  
Olayemi Tope Arowosegbe ◽  
...  
Keyword(s):  
Host Plants ◽  
Rapd Markers ◽  
Multiple Sources ◽  
Citrus Aurantifolia ◽  
Ocimum Gratissimum ◽  
Aleurodicus Dispersus ◽  
Wide Range ◽  
Fixation Indices ◽  
Rapid Amplification ◽  
Safety Strategy

The spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae), has a wide range of anatomy, physiology, behaviour, and ecology depending on the host plant. This research looked at the genetic variations between A. dispersus populations on two separate host plants (Citrus aurantifolia and Ocimum gratissimum). The existence of host-related genetic variation in A. dispersus populations was determined using Rapid Amplification of Polymorphic DNA (RAPD) markers. Our findings revealed that the A. dispersus populations on the two host plants had a considerable amount of genetic divergence. The spiralling whiteflies on the adaxial part of Citrus aurantifolia were genetically distinct from those on the abaxial part of the same plants. Various population genetic parameters such as heterozygosity, Nei's genetic gap, and fixation indices (FST) revealed that spiralling whitefly populations vary genetically, which may be attributable to spiralling whitefly populations originating from multiple sources. These findings also have consequences for the invasive pest's quarantine safety strategy.

SPECIES, HOST RANGE, AND IDENTIFICATION KEY OF WHITEFLIES OF BOGOR AND SURROUNDING AREA

2019 ◽  
Vol 18 (2) ◽  
pp. 127
Author(s):  
Purnama Hidayat ◽  
Denny Bintoro ◽  
Lia Nurulalia ◽  
Muhammad Basri
Keyword(s):  
Host Range ◽  
Host Plants ◽  
Ornamental Plants ◽  
Identification Key ◽  
Agricultural Crops ◽  
Surrounding Area ◽  
Aleurodicus Dispersus ◽  
Agricultural Plants ◽  
Surrounding Areas ◽  
Forest Plants

Species identification, host range, and identification key of whiteflies of Bogor and surrounding area. Whitefly (Hemiptera: Aleyrodidae) is a group of insects that are small, white, soft-bodied, and easily found on various agricultural crops. Whitefly is a phytophagous insect; some species are important pests in agricultural crops that can cause direct damage and can become vectors of viral diseases. The last few years the damage caused by whitefly in Indonesia has increased. Unfortunately, information about their species and host plants in Indonesia, including in Bogor, is still limited. Kalshoven, in his book entitled Pest of Crops in Indonesia, published in the 1980s reported that there were 9 species of whitefly in Indonesia. The information on the book should be reconfirmed. Therefore, this study was conducted to determine whitefly species and its host plants in Bogor and its surroundings. Whiteflies is identified based on the ‘puparia’ (the last instar of the nymph) collected from various agricultural plants, ornamental plants, weeds, and forest plants. A total of 35 species of whiteflies were collected from 74 species and 29 families of plants. The collwcted whiteflies consist of four species belong to Subfamily Aleurodicinae and 31 species of Subfamily Aleyrodinae. The most often found whitefly species were Aleurodicus dispersus, A. dugesii, and Bemisia tabaci. A dichotomous identification key of whiteflies was completed based on morphological character of 35 collected species. The number of whitefly species in Bogor and surrounding areas were far exceeded the number of species reported previously by Kalshoven from all regions in Indonesia.

Memories of Tiananmen

2021 ◽  
Author(s):  
Francis Lee ◽  
Joseph Man Chan
Keyword(s):  
Hong Kong ◽  
Collective Memory ◽  
Digital Media ◽  
Political Communication ◽  
Civil Liberties ◽  
Significant Degree ◽  
Historical Period ◽  
Multiple Sources ◽  
News Reports ◽  
Wide Range

This book analyzes how collective memory regarding the 1989 Beijing student movement and the Tiananmen crackdown was produced, contested, sustained, and transformed in Hong Kong between 1989 and 2019. Drawing on data gathered through multiple sources such as news reports, digital media content, vigil onsite surveys, population surveys, and in-depth interviews with activists, rally participants, and other stakeholders, it identifies six key processes in the dynamics of social remembering: memory formation, memory mobilization, memory institutionalization, intergenerational transfer, memory repair, and memory balkanization. Memories of Tiananmen demonstrates how a socially dominant collective memory, even one the state finds politically irritable, can be generated and maintained through constant negotiation and efforts by a wide range of actors. While the book mainly focuses on the interplay between political changes and Tiananmen commemoration in the historical period within which the society enjoyed a significant degree of civil liberties, it also discusses how the trajectory of the collective memory may take a drastic turn as Hong Kong's autonomy is abridged. The book promises to be a key reference for anyone interested in collective memory studies, social movement research, political communication, and China and Hong Kong studies.

Ustilago hypodytes. [Descriptions of Fungi and Bacteria].

1984 ◽  
Author(s):  
J. E. M. Mordue
Keyword(s):  
New Zealand ◽  
North America ◽  
South America ◽  
Root System ◽  
Geographical Distribution ◽  
Host Plants ◽  
Meristematic Tissue ◽  
Wide Range ◽  
Vegetative Multiplication ◽  
Established Infection

Abstract A description is provided for Ustilago hypodytes. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: A wide range of grasses, including species of Agropyron (many), Ammophila, Brachypodium, Bromus, Calamagrostis, Diplachne, Distichlis, Elymus (many), Festuca, Glyceria, Hilaria, Hordeum, Haynaldia, Lygeum, Melica, Orysopsis, Panicum, Phalaris, Phleum, Poa (many), Puccinellia, Secale, Sitanion, Sporobolus, Stipa (many), and Trisetum. DISEASE: Stem smut of grasses. GEOGRAPHICAL DISTRIBUTION: Chiefly a temperate species found in Europe (including Denmark, Finland, France, Germany, Hungary, Italy, Romania, Sweden, Switzerland, UK, USSR, Yugoslavia) and North America (Canada, USA) and extending to central and South America (Argentina, Peru, Uruguay), N. Africa (Libya, Morocco, Tunisia), Japan, Australia and New Zealand. TRANSMISSION: Not fully understood, though inoculation experiments have demonstrated that infection occurs in mature vegetative plants (possibly through meristematic tissue), not seeds or flowers (22, 240; 24, 511). Once established, infection is systemic, probably overwintering in the root system and spreading by vegetative multiplication of host plants as well as from plant to plant (24, 511; 19, 720).

scholarly journals Onorchard habitats for Nysius huttoni an important kiwifruit passenger pest

2014 ◽  
Vol 67 ◽  
pp. 326-326
Author(s):  
C.A. Rowe ◽  
M.G. Hill ◽  
D.P. Logan
Keyword(s):  
Native Species ◽  
Host Plants ◽  
Ground Vegetation ◽  
Preliminary Survey ◽  
Weed Species ◽  
Quarantine Pest ◽  
Polygonum Aviculare ◽  
Brassica Crops ◽  
Wide Range ◽  
High Incidence

Nysius huttoni is a native species of wheat bug which is an occasional quarantine pest on export kiwifruit Wheat bug has a wide range of host plants including wheat and brassica crops as well as many weed species The kiwifruit harvest of 2013 had a high incidence of wheat bug finds on fruit in packhouses In response an orchard survey was undertaken to identify orchard habitats used by wheat bug Twentyfive orchards where wheat bug was found during packing in 2013 were surveyed from the Te Puke area from February to March At each orchard four habitats were searched (1) ground vegetation under the kiwifruit canopy (2) the loadout zone (3) edge of the loadout zone and (4) grassland surrounding the was found in and around the loadout zone associated with weed species notably Polygonum aviculare the dominant weed species in loadout zones No wheat bug was found under the kiwifruit canopy and the remaining 4 were found in grassland This preliminary survey suggests that the risk of wheat bug infestation can be reduced considerably by keeping loadout zones free of weeds during spring and summer

scholarly journals Comparison and evaluation of statistical error models for scRNA-seq

2021 ◽  
Author(s):  
Saket Choudhary ◽  
Rahul Satija
Keyword(s):  
Linear Models ◽  
Negative Binomial ◽  
Statistical Error ◽  
Rna Seq ◽  
Multiple Sources ◽  
Error Models ◽  
Wide Range ◽  
Data Driven Approach ◽  
Downstream Analysis ◽  
Experimental Processing

Heterogeneity in single-cell RNA-seq (scRNA-seq) data is driven by multiple sources, including biological variation in cellular state as well as technical variation introduced during experimental processing. Deconvolving these effects is a key challenge for preprocessing workflows. Recent work has demonstrated the importance and utility of count models for scRNA-seq analysis, but there is a lack of consensus on which statistical distributions and parameter settings are appropriate. Here, we analyze 58 scRNA-seq datasets that span a wide range of technologies, systems, and sequencing depths in order to evaluate the performance of different error models. We find that while a Poisson error model appears appropriate for sparse datasets, we observe clear evidence of overdispersion for genes with sufficient sequencing depth in all biological systems, necessitating the use of a negative binomial model. Moreover, we find that the degree of overdispersion varies widely across datasets, systems, and gene abundances, and argues for a data-driven approach for parameter estimation. Based on these analyses, we provide a set of recommendations for modeling variation in scRNA-seq data, particularly when using generalized linear models or likelihood-based approaches for preprocessing and downstream analysis.

scholarly journals PERSPECTIVES OF BREEDING OF VEGETABLE CROPS OF FABACEAE FAMILY TO BEAN YELLOW MOSAIC VIRUS (Potyvirus, Potyviridae) RESISTANCE IN THE CONDITIONS OF MOSCOW REGION

2018 ◽  
pp. 77-83
Author(s):  
I. A. Engalycheva ◽  
E. G. Kozar ◽  
A. A. Antoshkin ◽  
E. P. Pronina ◽  
Y. G. Volkov ◽  
...  
Keyword(s):  
Causative Agent ◽  
Host Plants ◽  
Far East ◽  
Diagnostic Methods ◽  
Moscow Region ◽  
Kidney Bean ◽  
Yellow Mosaic Virus ◽  
Distribution Area ◽  
Sources Of Resistance ◽  
Wide Range

In the context of climate change phytomonitoring of the prevalence of the most common viral pathogens on the crops becomes even more important, because during the last decades the harmfulness of those pathogens, in particular Bean yellow mosaic (BYMV) has grown in intensity. The causative agent as the most members of Рotyvirus genus, has a wide range of host plants belonging to various families including Fabaceae. In Russia the virus was for the first time identified in the south of the Far East, where in the middle of XX century the massive damage of clove, lupine, sweet pea, pea, bean and Russian bean was observed. The distribution area of BYMV considerably expanded after advancement of heat-loving leguminous crops towards north. During the last years epiphytotics were reported in the planted crops of kidney bean (Phasйolus vulgбris L.), and Russian bean (Faba bona Medik. var. major Harz.) under conditions of temperate continental climate of nonchernozem belt in the RF. It is not feasible to eradicate natural BYMV foci, while the control of the causative agent carriers as a preventive measure is not very effective. There fore at present the search for the sources of resistance to BYMV and creation of parent selection material is a priority area of our phytopatologic research. At the present stage the tasks included: identification and study of the properties of BYMV Moscow isolates; integral assessment of resistance and other economically valuable characteristics of collection material and breeding stock material of kidney bean (810 specimens) and Russian bean (40 specimens) generated in the Laboratory of Legume Selection and Seed Production, Federal State Budgetary Scientific Institution “Federal Scientific Vegetable Center”. To achieve the goal visual, serological diagnostic methods were used together with biotesting and electron microscopy. The research revealed special physical-chemical characteristics of BYMV Moscow isolates characterized by 100% harmfulness when occurred as co-infection with the other viruses. The main symptoms caused by the above isolates in indicator plants and host plants under conditions of Moscow Region have been described. Evaluation of collection and selection materials of kidney bean and Russian bean formed the basis for identification of the sources of resistance to BYMV exhibiting integrated economically valuable properties (early ripeness, bean shape and color, productivity, etc.). These specimens have been included into selection program of the Federal Research Vegetable Center which is aimed on creation of high-productive varieties of the kidney bean meeting the modern market demands.

scholarly journals Cytospora (Diaporthales) in China

2020 ◽  
Vol 45 (1) ◽  
pp. 1-45 ◽  
Author(s):  
X.L. Fan ◽  
J.D.P. Bezerra ◽  
C.M. Tian ◽  
P.W. Crous
Keyword(s):  
New Species ◽  
Host Plants ◽  
Southwest China ◽  
New Combination ◽  
Large Collection ◽  
Dna Phylogeny ◽  
The Past ◽  
Worldwide Distribution ◽  
Wide Range ◽  
Woody Host

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.

scholarly journals Climate-dependent propagation of precipitation uncertainty into the water cycle

2020 ◽  
Author(s):  
Ali Fallah ◽  
Sungmin O ◽  
Rene Orth
Keyword(s):  
Hydrological Model ◽  
Water Cycle ◽  
State Of The Art ◽  
Rain Gauge ◽  
Multiple Sources ◽  
Current State ◽  
Wide Range ◽  
The Impact ◽  
Conceptual Hydrological Model

Abstract. Precipitation is a crucial variable for hydro-meteorological applications. Unfortunately, rain gauge measurements are sparse and unevenly distributed, which substantially hampers the use of in-situ precipitation data in many regions of the world. The increasing availability of high-resolution gridded precipitation products presents a valuable alternative, especially over gauge-sparse regions. Nevertheless, uncertainties and corresponding differences across products can limit the applicability of these data. This study examines the usefulness of current state-of-the-art precipitation datasets in hydrological modelling. For this purpose, we force a conceptual hydrological model with multiple precipitation datasets in > 200 European catchments. We consider a wide range of precipitation products, which are generated via (1) interpolation of gauge measurements (E-OBS and GPCC V.2018), (2) combination of multiple sources (MSWEP V2) and (3) data assimilation into reanalysis models (ERA-Interim, ERA5, and CFSR). For each catchment, runoff and evapotranspiration simulations are obtained by forcing the model with the various precipitation products. Evaluation is done at the monthly time scale during the period of 1984–2007. We find that simulated runoff values are highly dependent on the accuracy of precipitation inputs, and thus show significant differences between the simulations. By contrast, simulated evapotranspiration is generally much less influenced. The results are further analysed with respect to different hydro-climatic regimes. We find that the impact of precipitation uncertainty on simulated runoff increases towards wetter regions, while the opposite is observed in the case of evapotranspiration. Finally, we perform an indirect performance evaluation of the precipitation datasets by comparing the runoff simulations with streamflow observations. Thereby, E-OBS yields the best agreement, while furthermore ERA5, GPCC V.2018 and MSWEP V2 show good performance. In summary, our findings highlight a climate-dependent propagation of precipitation uncertainty through the water cycle; while runoff is strongly impacted in comparatively wet regions such as Central Europe, there are increasing implications on evapotranspiration towards drier regions.

scholarly journals Multiple sources of signal amplification within the B cell Ras/MAPK pathway

2018 ◽  
Author(s):  
Justin D. Mclaurin ◽  
Orion D. Weiner
Keyword(s):  
Positive Feedback ◽  
Signal Amplification ◽  
Mapk Pathway ◽  
Threshold Level ◽  
Cell Types ◽  
Multiple Sources ◽  
Analog To Digital ◽  
Ras Activation ◽  
Wide Range ◽  
Erk Activity

AbstractThe Ras-Map kinase (MAPK) cascade underlies functional decisions in a wide range of cell types and organisms. In B cells, positive feedback-driven Ras activation is the proposed source of the digital (all-or-none) MAPK responses following antigen stimulation. However, an inability to measure endogenous Ras activity in living cells has hampered our ability to test this model directly. Here we leverage biosensors of endogenous Ras and ERK activity to revisit this question. We find that BCR ligation drives switch-like Ras activation and that lower BCR signaling output is required for the maintenance versus the initiation of Ras activation. Surprisingly, digital ERK responses persist in the absence of positive feedback-mediated Ras activation, and digital ERK is observed at a threshold level of Ras activation. These data suggest an independent analog-to-digital switch downstream of Ras activation, and reveals that multiple sources of signal amplification exist within the Ras-ERK module of the BCR pathway.

Nodulation studies on legumes exotic to Australia: symbiotic relationships between Chamaecytisus palmensis (tagasaste) and Lotus spp

1994 ◽  
Vol 34 (3) ◽  
pp. 385 ◽  
Author(s):  
RR Gault ◽  
A Pilka ◽  
DM Hebb ◽  
J Brockwell
Keyword(s):  
Host Plants ◽  
Root Nodule ◽  
Pattern Analysis ◽  
Analysis Procedure ◽  
Nodule Bacteria ◽  
Symbiotic Relationships ◽  
The Third ◽  
Rhizobium Loti ◽  
Wide Range ◽  
Bradyrhizobium Sp

Strains of rhizobia were isolated from soil around the roots of tagasaste (Chamaecytisus palmensis) growing at 15 widely separated locations in south-eastem Australia. A further collection of strains of both Rhizobium loti and Bradyrhizobium sp. (Lotus) was assembled from 18 legumes including Lotus and other species symbiotically related to Lotus. The strains were used to inoculate tagasaste and 4 species of Lotus in experiments conducted under bacteriologically controlled conditions in a temperature-controlled glasshouse. Tagasaste formed nodules and fixed N2 with all of its homologous rhizobia but there was a wide range of effectiveness among the 15 strains. Tagasaste also formed nodules with each of the 18 strains from other species but fixed N2 with only 10. Four species of Lotus were inoculated with 3 tagasaste strains. One strain nodulated each species and fixed N2 with L. conimhricensis and L. corniculatus but not with L. parviflorus or L. pedunculatus. A second tagasaste strain formed nodules with all 4 Lotus spp. but did not fix N2, while the third nodulated only L. pedunculatus but did not fix N2. A pattern analysis based on the nodulating ability of the host plants in association with 21 strains showed that tagasaste and L. corniculatus formed 1 symbiotic group, and the other 3 Lotus species formed a third group. The pattern analysis procedure based on nodulating capacity of 21 rhizobial strains in association with the 5 host species indicated substantial symbiotic diversity within the collection, with the strains comprising 8 different symbiotic groups. No strain was highly effective on both tagasaste and any of the 4 species of Lotus. Data were insufficient to classify the root-nodule bacteria of tagasaste as either Rhizobium loti or Bradyrhizobium sp. (Lotus).

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