Molecular profiling of rhizosphere bacterial communities associated with Prosopis juliflora and Parthenium hysterophorus

Prosopis juliflora and Parthenium hysterophorus are the two arid, exotic weeds of India that are characterized by distinct, profuse growth even in nutritionally poor soils and environmentally stressed conditions. Owing to the exceptional growth nature of these two plants, they are believed to harbor some novel bacterial communities with wide adaptability in their rhizosphere. Hence, in the present study, the bacterial communities associated with the rhizosphere of Prosopis and Parthenium were characterized by clonal 16S rRNA gene sequence analysis. The culturable microbial counts in the rhizosphere of these two plants were higher than bulk soils, possibly influenced by the root exudates of these two plants. The phylogenetic analysis of V1_V2 domains of the 16S rRNA gene indicated a wider range of bacterial communities present in the rhizosphere of these two plants than in bulk soils and the predominant genera included Acidobacteria, Gammaproteobacteria, and Bacteriodetes in the rhizosphere of Prosopis, and Acidobacteria, Betaproteobacteria, and Nitrospirae in the Parthenium rhizosphere. The diversity of bacterial communities was more pronounced in the Parthenium rhizosphere than in the Prosopis rhizosphere. This culture-independent bacterial analysis offered extensive possibilities of unraveling novel microbes in the rhizospheres of Prosopis and Parthenium with genes for diverse functions, which could be exploited for nutrient transformation and stress tolerance in cultivated crops.     

Germination ecology of the weed Parthenium hysterophorus in eastern Ethiopia

Germination ecology of Parthenium hysterophorus, recently introduced to Ethiopia, was studied in a series of experiments. Viability of the seeds was greater than 50% after 26 months of burial in the soil indicating the potential build‐up of a substantial persistent soil seed bank. A short period of dry storage was sufficient to overcome a light requirement for germination in a minor fraction of the seeds. Likewise, seeds exhumed from burial showed an increase in germination ability in darkness over time, with a weak tendency for seasonal cyclicity in dormancy level at one of two sites. Germination occurred at the mean minimum (10°C) and maximum (25°C) temperatures of the collection sites, as well as over a wide range of fluctuating (12/2°C‐35/25°C) temperatures in light. No germination of P. hysterophorus seeds occurred at osmotic potentials < ‐0.52 MPa (at 27°C), the species being less tolerant to moisture stress than sorghum grains. Most seedlings emerged from shallowly buried (< 0.5 cm) seeds and none from more than 5 cm depth. Naturally dispersed seeds required about 60 days, at a hot lowland site, to start emergence despite the presence of adequate rainfall, and higher number of seedlings emerged in undisturbed plots than in hand hoed plots. These experiments and field observations suggest that there are no obvious climatic conditions that may limit the germination of Parthenium hysterophorus in Ethiopia, but a high moisture requirement of the seeds for germination could be the major factor limiting germination during the dry season.     

Vermicomposting--An effective tool for the management of invasive weed Parthenium hysterophorus

This study reports the results of vermicomposting with Eisenia fetida of Parthenium hysterophorus mixed with cow dung in different ratios (25%, 50% and 75%) in a 18 weeks experiment. In all the treatments, a decrease in pH, OC_total and C:N ratio, but increase in EC, N_total, P_aval, Ca_total, K_total and heavy metals was recorded. The cocoons production and growth rate (biomass gain worm⁻¹ day⁻¹) were maximum in 100% cow dung. The results indicated that parthenium can be a raw material for vermicomposting if mix with cow dung in appropriate quantity.     

Distributions of invasive weed Parthenium (Parthenium hysterophorus L.) in the University campus Peshawar KPK

A very interesting survey was performed to measure the distribution of invasive Parthenium (Parthenium hysterophorus L.) weed in the University Campus, Peshawar, the capital city of Khyber Pakhtunkhwa province. The University Campus comprised on; The University of Peshawar, Islamia College University, The University of Agriculture Peshawar, Pakistan Forest Institute and the New Developmental Research Farm. In these selected areas Parthenium weed distribution was measured in particular the academic, residential and research farm. Moreover, the survey also investigated the impact of parthenium weed upon native weeds flora inside the University campus. A 1m² quadrat was used to collect the data. During the survey, a total of 32 weeds species were recorded belonging to 18 different families and 32 genera, the life cycle of 23 weeds were annual while 9 weeds have a perennial. The data were recorded on absolute density (%), relative density (%), absolute frequency (%), relative frequency (%) and importance values (%) of parthenium weed and others flora. The collected data show that parthenium weed was the most dominant species having 76.8 m^?2 plants density in the NDF and (32.0 m^?2) at Islamia College University. However, the highest frequency (100%) of Parthenium was observed for The University of Agriculture, while minimum (80%) occurred in the Agronomy field. A More, the relative frequency of Parthenium was maximum (25%) in Islamia College; whereas, it's minimum (12.9%) at Agronomy field. Finally, the Importance Value of Parthenium indicates the highest (45.98%) at Dairy Farm followed by (40.33%) at the Horticulture field's area. In short, the Parthenium weed becomes more problematic and replaces all the native flora in the non-crop area specially Dicanthium annulatum L. a native grass species on the ridges of the field being replaced by parthenium. Due to no proper management and high growth rate, nowadays it becomes like a superweed in the KPK and especially in Pakistan. So, the management of Parthenium weed requires the call attention from the Govt. policymaker and proper quarantine inspection to conserve the native flora and field crops to get maximum crop yield.     

Development of microsatellite markers for the invasive weed Parthenium hysterophorus (Asteraceae)

? Premise of the study: Microsatellite primers were developed for Parthenium hysterophorus to investigate its genetic structure and genetic diversity. ? Methods and Results: Using the combined biotin capture method, 15 microsatellite primer sets were isolated and characterized. All markers showed polymorphism, and the number of alleles per locus ranged from two to nine across 60 individuals from two populations. The observed and expected heterozygosities ranged from 0.117 to 0.750 and from 0.182 to 0.835, respectively. ? Conclusions: These markers will be useful for investigating the invasion history of this weed globally and to help characterize its invasiveness.     

Invasion status and impacts of parthenium weed (Parthenium hysterophorus) in West-Central region of Bhutan

Parthenium weed (Parthenium hysterophorus L.) is an invasive alien plant species that is spreading rapidly all over the world. With globalization and climate change, it will continue to spread, posing threats to agriculture, biodiversity and the environment. To determine its invasion and impacts in Bhutan, an investigation was undertaken in West-Central Bhutan using a questionnaire survey, complemented by MaxEnt modelling. Most farmers (19–30%) recall having seen parthenium for the last 11–15 years, or more. Infestations of parthenium differed significantly (P?<?0.05) across three districts for dryland, orchards, fallow land and pastures, but not in rice fields and on roadsides. The most intensely invaded land types were fallow land, pastures, and roadsides, with farmers perceiving it as ‘somewhat common’(score?~?3) and ‘common’ (score?~?4) weed. Farmers’ perceptions of the invasiveness of parthenium weed were high at 77% (Wangdue), 80% (Punakha), and 88% (Tsirang), considering it as at least ‘somewhat invasive’, or higher. Only 13–25% of respondents scored the weed as ‘highly invasive’. Parthenium invasion significantly (P?<?0.01 to 0.001) escalated the cost of production, reduced fodder quality, supressed native species and caused allergies to the locals in the study districts. Further, MaxEnt modelling of parthenium distribution was undertaken, using the parthenium presence-only data and bioclimatic variables, under 2 CO₂ emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), i.e. Representative Concentration Pathways (RCP2.6 and 8.5). The projections showed discernible spatial changes in climate suitability over 2070, mostly in the mid- and high-altitude zones, indicating aggressive incursion into Bhutan’s important agro-ecological landscapes. The findings, highlight the urgent need to initiate parthenium management strategies for food production and natural resources.

     

Isolation and characterization of two antigenic glycoproteins from the pollen of Prosopis juliflora

Two antigenically active glycoprotein fractions were isolated from crude extract of the pollen of Prosopis juliflora using DEAE-cellulose ion exchange chromatography. The glycoproteins gave single band on polyacrylamide gel electrophoresis. The molecular weight of these two glycoprotein was 20,000 and 10,000 as determined by gel filtration on Sephadex G-75. With the help of crossed immunoelectrophoresis and gel diffusion crude extract exhibited twelve and three precipitating antigens suggesting its heterogeneous nature; and the purified glycoprotein fractions however formed single precipitin band on gel diffusion test and immunoelectrophoresis. As tested by ELISA the polyclonal antisera raised in rabbit showed strong binding affinity with glycoprotein of MW 20,000. These result indicates that the two glycoprotein fractions are not antigenically identical.     

Spread pathways of the invasive weed Parthenium hysterophorus L.: The potential for water dispersal

Parthenium hysterophorus L. (Asteraceae) utilises multiple mechanisms to facilitate its dispersal. It has been speculated that the cypsela, the propagule of this species, can be dispersed by water under varying environmental conditions. Four experiments were conducted to test this hypothesis, using simulated shaking and immersion to test floating ability and viability of the propagule in water. The influence of the acidity of the immersion medium on cypsela viability was also examined. Our results revealed that the freshly harvested cypselae could float on river water for at least 20 days, although around 80% sank within a week if moderate or severe turbulence was applied. Sinkage was observed to be more rapid in naked seeds (within a day) than in cypsela (within a week). On still water surfaces, germination occurred within a week but extended to 1.5 weeks under turbulent conditions due to sinkage. In river water, initial germination of floating cypselae was greater (70%) under illuminated conditions as compared to dark conditions (20%). The viability of immersed cypselae was found to remain high in distilled water for 45 days, when immersion was in cool conditions (10 or 15°C). However, in moderate (20 and 24°C) or warm (25 and 30°C) conditions, the rate of viability loss increased, and at 34°C, around 50% of the cypselae died after 20 days of immersion. Similar trends for cypselae longevity were observed in studies using river and pond water; viability loss was faster, especially in pond water. In summary, a proportion of cypselae will float in turbulent water and could be carried significant distances in river systems. Immersed cypselae can remain viable for weeks and can germinate on contact with soil. Water bodies or floods are therefore considered as important pathways in parthenium weed dispersal; hence, post‐flood monitoring is strongly recommended to minimise its spread.     

Pseudoguaianolides from the flowers of Parthenium hysterophorus

Chemical investigation on the flowers of Parthenium hysterophorus has resulted in the isolation of four new pseudoguaianolides, hysterones A-D along with the known compounds, parthenin, coronopilin, 2beta-hydroxycoronopilin and tetraneurin-A. The structures of the new compounds were established by interpretation of their spectral (1D and 2D NMR) data. The X-ray crystallographic analysis of hysterones A and C was also carried out.     

Occurrence of hysterin and dihydroisoparthenin in Parthenium hysterophorus

Two sesquiterpene lactones, hysterin and dihydroisoparthenin, have been identified in Parthenium hysterophorus from Argentina and Jamaica by TLC and NMR.     

Identification of Prosopis juliflora and Prosopis pallida Accessions Using Molecular Markers

There has been much taxonomic confusion over the identification of Prosopis species, especially where introduced. Prosopis juliflora is the most widespread species in the arid and semi-arid tropics, although it has been confused with other species, particularly the closely related Prosopis pallida. In this study, RAPDs markers were used for the first time to distinguish between these species. Eighteen primers were used in amplification reactions, which yielded an average of 120 bands per accession. A dendrogram showing genetic similarities among accessions was constructed using UPGMA cluster analysis and the Nei and Li similarity coefficient. The genetic similarity observed between P. juliflora and P. pallida is similar to the value in sympatric Prosopis species in North America, and reconsideration of the series rank in section Algarobia is suggested. Species-specific markers confirmed that material in Burkina Faso is P. juliflora, but suggested that material collected in Brazil, Cape Verde and Senegal is P. pallida, whereas this has previously been identified as P. juliflora.     

Pseudomonas putida NBRIC19 provides protection to neighboring plant diversity from invasive weed Parthenium hysterophorus L. by altering soil microbial community

Parthenium hysterophorus L. (Parthenium) is an invasive weed species which is spreading worldwide affecting natural ecological systems, biodiversity, crop production and human health. The present study was conducted to evaluate the potential of plant growth promoting Pseudomonas putida NBRIC19 in detoxifying the phytotoxic effect of Parthenium. Significant increase in C/N ratio, macronutrients, and micronutrients was observed in P. putida NBRIC19-treated soil. P. putida NBRIC19 treatment of the soil provided protection to plant communities in Parthenium invaded area, as the species diversity had increased in the treatment as compared to non-bacterized soil. P. putida NBRIC19 treatment besides Parthenium, also succeeded in controlling other weed species like Commelina benghalensis and Cynodon dactylon. In addition to this, the impact of Parthenium was also studied on functional microbial diversity based on carbon source utilization pattern. It was observed that P. putida NBRIC19 treatment of soil had shifted the microflora in such a manner that utilization of toxic allelochemicals increased to lessen their phytotoxic effect. Taken together, these results suggest that soil treatment with P. putida NBRIC19 may be used as a promising biological control measure for controlling the phytotoxic effect of Parthenium and in protecting ecosystem integrity of neighboring plants in Parthenium invaded areas.     

Adaptation strategies of two leaf cohorts of Prosopis juliflora produced in spring and monsoon

Photosynthetica - Prosopis juliflora is an invasive leguminous tree species growing profusely under wide environmental conditions. Primary objective of this study was to investigate adaptation...     

Correction to: Invasion status and impacts of parthenium weed (Parthenium hysterophorus) in West-Central region of Bhutan

Biological Invasions - A correction to this paper has been published: https://doi.org/10.1007/s10530-021-02573-w     

Trichome studies in Parthenium hysterophorus and their taxonomic importance

In Parthenium hysterophorus L. four trichome types i.e. (1) cylindrical hair, (2) moniliform hair, (3) simple multiseriate hair and (4) shaggy hair, have been recognized mostly on the basis of their structural differences. In the past, these types have not been observed in any species of Parthenium studied so far. Out of these four, two types i.e. cylindrical and moniliform hairs are known to occur in the Compositae and remaining two i.e. simple multiseriate and shaggy hairs are the new forms for the family and have been observed for the first time in presently investigated species. Trichomes are an important taxonomic tool in distinguishing between genera and species. Trichomes of the different species of Parthenium as noticed from their structure are useful in distinguishing these species and even their corresponding organs.     

樱桃属(Cerasus)植物根围微生物多样性

研究了樱桃属(Cerasus) 5种植物本溪山樱(Cs)、大青叶(Cp)、马哈利(Cm)、考特(Cap)、早红宝石(Ca)各主要生长期根围微生物数量、种群组成、Shannom-Wiener指数(H)、丰富度(S)、Pielou均匀度指数(J)、Simpson 优势度(D)和优势微生物种群变化动态.从樱桃根围共分离到细菌18属,优势菌属主要为假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)和黄杆菌属(Flavobacterium);放线菌为链霉菌的12个类群,优势类群主要为白色类群(Albosporus)、吸水类群(Hygroscopicus)和黄色类群(Flavus);真菌6属,优势菌属为青霉属(Penicillium).樱桃根围微生物的多样性指数(H)、丰富度指数(S)、均匀度指数(J) 及优势度指数(D) 随樱桃种类不同而发生变化,细菌的多样性和丰富度指数为Ca＞Cs＞Cp＞Cm＞Cap,放线菌为Ca＞Cp＞Cs＞Cm＞Cap,真菌为Cm＞Ca＞Cp＞Cs＞Cap.各生长期根围微生物种类与数量发生变化,新梢迅速生长期Ca、Cs、Cp和Cm根围微生物种类与数量较多,新梢停长期Cap根围微生物种类与数量较多,落叶期5种樱桃属植物根围微生物种类与数量均较少.     

Exotic Prosopis juliflora suppresses understory diversity and promotes agricultural weeds more than a native congener

Plant Ecology - Exotic invasive plant species alter ecosystems and locally extirpate native plant species, and by doing so alter community structure. Changes in community structure may be...     

Two flavonoid glycosides from the bark of Prosopis juliflora

Two new glycosides, kaempferol 4′-methyl ether 3-O-β-d-galactopyranoside and retusin 7-O-neohesperidoside, have been characterized from the stem bark of Prosopis juliflora.     

Fractionation and immunochemical characterization of Prosopis juliflora pollen allergen

Prosopis juliflora pollen grain crude extract gave six different molecular weight fractions varied from 81,000 to 13,000 dalton on Sephadex G-100 gel filtration. The purity of fractions of Prosopis juliflora pollen extract were checked by polyacrylamide gel electrophoresis. The fraction had an molecular weight 20,000 dalton showed four absorption maxima whereas other fractions had single absorption maxima. Allergenic activity and nature of allergens were evaluated by in vitro Radioallergosorbent test and in vivo Passive Cutaneous Anaphylaxis test. All these tests indicated that most allergenic fractions were in the 20,000 molecular weight.     

Aerobiology and some chemical parameters of Parthenium hysterophorus pollen

Parthenium hysterophorus, a recently invaded toxic weed, in Eastern India, is now growing gregariously in Salt Lake City — a newly developed township situated in the eastern fringe of the metropolitan city of Calcutta. The floristic survey revealed that most of the trees and shrubs in Salt Lake City have been introduced except for a few, which were recorded as natural occurrence, Parthenium being most prevalent among them. Ecological associations of Parthenium in various localities of Salt Lake City were also investigated. Aerobiological survey was done using a Burkard seven day Volumetric Spore Trap, with the object to record the occurrence of Parthenium pollen in the air of Salt Lake in different seasons along with other airborne types. A total of 45 pollen and 60 fungal spore types were trapped and recorded. The frequency of grass and cyperaceous pollen were found to be dominant followed by Trema. Frequency of Parthenium was relatively insignificant. Chemical analyses of the pollen grains of Parthenium including assay of carbohydrate, lipid, protein, etc., were done. Clinically one out of six patients showed ELISA positive reaction to Parthenium pollen.