• Journal of Ecology and Environment
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• 제44권4호
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• pp.222-228
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• 2020

Background: Parthenium hysterophorus is a noxious invasive weed in tropical and subtropical regions of the world, including Nepal. Among 11 species of biological control agents released to control P. hysterophorus in Ausrtalia, winter rust Puccina abrupta var. partheniicola arrived fortuitously and has established in Kathmandu Valley, Nepal, nearly a decade back. However, the prevalence and effectiveness of this rust as a biological control agent in Kathmandu remain unknown. To address this knowledge gap, a roadside survey was done at an interval of 2 ± 0.25 km in Kathmandu Valley to assess the P. abrupta var. partheniicola incidence and its impacts on P. hysterophorus. Infested individuals of P. hysterophorus were further divided into four severity classes (very low, low, medium, and high), and rust incidence was calculated. The impact of the winter rust on the growth of P. hysterophorus was assessed by comparing biomass and seed output of infested and non-infested individuals. Results: Among 81 locations where P. hysterophorus was present in the Kathmandu Valley, winter rust infestation was observed at 98% locations. At some locations within Kathmandu Valley such as Tinkune, Kirtipur, Chabahil, Buddha Chowk, and Dhobighat, the impacts of the rust on P. hysterophorus were medium to high. Aboveground biomass and seed output of P. hysterophorus were reduced by 47% and 73%, respectively, due to winter rust infestation. The study indicates that winter rust incidence is widespread in Kathmandu Valley with very low to high levels of damages to P. hysterophorus depending on the localities. Conclusion: The rust has, therefore, a potential to reduce the growth performance of P. hysterophorus, and it can be used as a component of integrated management of P. hysterophorus by introducing to other suitable areas in Nepal.

• Journal of Ecology and Environment
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• 제46권1호
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• pp.8-17
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• 2022

Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m². Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

• The Korean Journal of Ecology
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• 제22권2호
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• pp.85-88
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• 1999

Aqueous and dichloromethane (DCM) extracts of leaves, root bark and inflorescences of Parthenium hysterophorus L. at various concentrations were used to quantify its allelopathic potential against Indigofera tinctoria, Amaranthus viridis, A. gangeticus, Phaseolus mungo (cv. CO 1), Sorghum vulgare (cv. SPT- 462). Pennisetum typhoideus (cv. WCC-75) and Eleusine corocana (cv. CO 1). The aqueous extracts were more inhibitory than the DCM extracts to the germination and seedling growth of the plants studied. The relative rate of inhibition increased in the order of inflorescences. leaves and root bark in the aqueous extracts. whereas DCM root bark and inflorescences extracts were promoted at lower concentrations.

• 환경생물
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• 제41권1호
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• pp.31-40
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• 2023

환경부에서 생태계교란식물로 추가 지정된 돼지풀아재비의 분포, 형태·생리·생태적 특성 그리고 다양한 제거방법 등을 정리하여 효율적인 관리방안을 제시하고자 한다. 중앙아메리카가 원산지인 돼지풀아재비는 전 세계적으로 45개국에서 발생하고 있지만, 우리나라에서는 경상남도 통영 및 창원의 일부지역에서만 생육하고 있다. 이 식물은 한해살이풀로 종자로 확산되며, 수입 농산물에 포함되거나 차량이나 농업용 기계에 부착되어 인근으로 그 영역을 넓히고 있다. 돼지풀아재비의 줄기와 뿌리에서 타감물질인 파르테닌 등이 분비되어 주변 식생의 발생을 억제한다. 또한 다양한 알레르겐을 함유하고 있어 인간과 가축에 피해를 주는 식물이다. 돼지풀아재비와 같은 유해식물이 발생되면 관계기관에 신고하는 제도적인 관리방안이 마련되어야 한다. 돼지풀아재비의 줄기를 절단하거나 제거하는 등의 물리적 방법 그리고 glyphosate와 같은 비선택성 제초제 처리로 방제할 수 있다. 생물학적 방제연구는 많이 수행되었으나, 우리나라의 법률과 제도의 미비로 국내에 적용 가능한 것은 제한적이다.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.301-310
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• 2012

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.

• Animal cells and systems
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• 제4권4호
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• pp.325-328
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• 2000

Parthenin was extracted from Parthenium hysterophorus L. leaves growing in northern part of India, and its effect was tested on the seed germination parameters and other related characteristics of Ageratum conyzoides L. weed. Parthenin proved phytotoxic to A. conyzoides as most of the studied parameters were inhibited. It may lead to a possible biological eradication of the A. cpnyzoides weed.

• Journal of Ecology and Environment
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• 제47권3호
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• pp.75-84
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• 2023

Background: Knowledge of the spatial trends of plant invasions in different habitats is essential for a better understanding of the process of these invasions. We examined the variation in invasive alien plant species (IAS) richness and composition at two spatial scales defined by elevation and habitat types (roadside, forest, and cultivated lands) in the Makawanpur district of Nepal. Following an elevation gradient ranging from 500 to 2,400 m asl along a mountain road, plant species cover was recorded within sample plots of size 10 m × 5 m. Systematic random sampling was adopted in every 100 m elevation intervals on three habitat types. Results: Altogether 18 invasive alien plants belonging to eight families were recorded within 60 plots, of which 14 species (representing 80%) were from tropical North and South America. The most common plants by their frequency were Ageratina adenophora, Chromolaena odorata, Bidens pilosa, Lantana camara, and Parthenium hysterophorus. We found a significant relationship between species composition and elevation in the study area. Low-elevation regions had a higher number of alien species as compared to high-elevation regions within different habitat types. Conclusions: The species richness and density of IAS were higher in the road site followed by the cultivated land and forest sites. This pattern occurred throughout the elevation range and habitats. IAS were found mostly in the open land with high sunlight availability. Information from such scientific assessment of invasive alien plants will assist in developing appropriate management plans in the Makawanpur district.