• The Plant Pathology Journal
• /
• 제39권3호
• /
• pp.290-302
• /
• 2023

Abamectin offers great protection against Bursaphelenchus xylophilus, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against B. xylophilus. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against B. xylophilus. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations preexposed to pre-determined concentrations of the formulations were inoculated onto Botrytis cinerea culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC₉₅ of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 ㎍/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 ㎍/ml both on Botrytis cinerea and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

• The Plant Pathology Journal
• /
• 제39권1호
• /
• pp.75-87
• /
• 2023

The pine wood nematode (PWN), Bursaphelenchus xylophilus is a well-known devastating pathogen of economic importance in the Republic of Korea and other countries. In the Republic of Korea, trunk injection of nematicides is the preferred method of control. In this study, the efficacy of 16 locally produced formulations of emamectin benzoate against the PWN are compared through determining their sublethal toxicities and reproduction inhibition potentials. Nematodes were treated with varying concentrations of the tested chemicals in multi-well culture plates, and rates of paralysis and mortality were determined after 24 h. Reproduction inhibition potential was tested by inoculating pre-treated nematodes onto Botrytis cinerea, and in pine twig cuttings. Despite the uniformity in the concentration of the active ingredient, efficacy was contrastingly different among formulations. The formulations evidently conformed to three distinct groups based on similarities in sublethal activity (group 1: LC₉₅ of 0.00768-0.01443 mg/ ml; group 2: LC₉₅ of 0.03202-0.07236 mg/ml, and group 3: LC₉₅ of as high as 0.30643-0.40811 mg/ml). Nematode paralysis generally occurred at the application dose of 0.0134-0.1075 ㎍/ml, and there were significant differences in nematode paralysis rates among the products. Nematode reproduction was only evident at lower doses both on B. cinerea and pine twigs, albeit the variations among formulations. Group 1 formulations significantly reduced nematode reproduction even at a lower dose of 0.001075 ㎍/ml. The variations in efficacy might be attributed to differences in inert ingredients. Therefore, there is need to analyze the potential antagonistic effects of the large number of additives used in formulations.

• Applied Biological Chemistry
• /
• 제35권5호
• /
• pp.367-374
• /
• 1992

이스라엘 잉어와 참잉어에 대한 농약의 독성 및 glycogen의 함량변화, 호소활성을 조사하고 농약 상호간의 협력작용의 여부를 조사하였다. $LC_{50}$치의 측정결과는 공시약제 중 endosulfan이 0.0079 ppm으로 가장 독성이 강했고 metalaxyl이 40 ppm 이상으로 가장 낮았다. 농약 상간의 협력작용은 IBP+isoprothiolane과 cartap+isoprothiolane 처리구에서 나타났으며 그 ratio(SR)는 각각 1.85, 1.53이었다. 효소활성의 경우 carboxylesterase와 glutathione S-transferase 모두 증가되었다. Esterase의 활성은 IBP 처리구에서 가장 높았고 isoprothiolane 처리구에서 제일 낮았으며, glutathione의 CDNB conjugation은 isoprothiolane 처리구에서 가장 높았고 isoprothiolane+cartap 처리구에서 가장 낮았다. LDH의 경우 isoprothiolane 처리구에서 활성이 가장 높았고 isoprothiolane+cartap 처리구에서는 가장 낮았다. Glycogen의 함량은 공시약제의 처리구 모두에서 감소를 보였으며 IBP 처리구에서 감소정도가 가장 높았다.

• 한국어병학회지
• /
• 제15권1호
• /
• pp.37-42
• /
• 2002

Effect of mercury (Hg) toxicity on survival, growth, feed efficiency and oxygen consumption were examined in the juvenile olive flounder. Paralichthys olivaceus. Fishes were exposed to sublethal concentrations of Hg ranging from 0 to 0.13mg/L for 6 weeks. Hg reduced survival rate in a concentration and exposure period-dependent way and suddenly reduction occurred at Hg concentrations greater than 0.05mg/L after 6 weeks. Growth rate and feed efficiency also significantly decreased at greater than 0.028 and 0.05 mg/L respectively. Oxygen consumption rate was significantly decreased to 25 and 32% than that of the control at the Hg concentration of 0.05 and 0.13 mg/L respectively. These results suggest that Hg toxicity inhibit physiological function including growth, feed efficiency and oxygen consumption in the juvenile olive flounder, resulting in survival failure at high concentration.

• 한국동물생명공학회지
• /
• 제37권3호
• /
• pp.176-182
• /
• 2022

Norflurazon is widely used on agricultural lands and has a high potential to pollute water sources. However, its effects on fish have not been fully elucidated. The purpose of our study was to determine whether norflurazon adversely affects the developmental stage of zebrafish, which are frequently used as a model system to evaluate the environmental impact of pollutants. Norflurazon interfered with the hatching of zebrafish embryos and induced several sublethal deformities including body length reduction, increased yolk sac volume, and enlargement of the pericardial region. We further examined the cardiotoxicity of norflurazon in the flk1:eGFP transgenic zebrafish line. The vascular network, mainly in the brain region, was significantly disrupted in norflurazon-exposed zebrafish. In addition, due to the failure of cardiac looping, norflurazon-exposed zebrafish had an abnormal cardiac structure. These developmental abnormalities were related to the apoptotic process triggered by norflurazon. Overall, the present study demonstrated the non-target toxicity of norflurazon by analyzing the hazardous effects of norflurazon on developing zebrafish.

• Environmental Analysis Health and Toxicology
• /
• 제14권4호
• /
• pp.217-222
• /
• 1999

Changes in certain fish behaviors are known to be very sensitive indicators of sublethal exposure to environmental contaminants. Therefore, behavioral toxicity tests, if properly designed, can be very useful to assess the influence of hazardous chemicals on fish. However, quantitative analysis of xenobiotic-mediated changes in locomotor behavior in fishes are rare, due mainly to the methodological difficulties. In general, fish movement has been known to be hypertrophic or hypotrophic according to the chemicals. As a study of fish behavioral toxicities, we qualified the swimming movement of Oryzias latipes using computer-automated video tracking system. Oryzias latipes was exposed to cadmium of 128 mg/L for 1 hour in a limited aquaria, then the total swimming distance, the average swimming velocity, the histogram of turning angles, and the turning frequency were analyzed. Fish treated with cadmium showed decreased swimming activities, decreased velocity, and decreased turning frequency, which means hypotrophic activity. From these results, the computer-automated video tracking system of this study seems to be a good tool for the evaluation of the potential ecotoxicological studies.

• 한국환경독성학회:학술대회논문집
• /
• 한국환경독성학회 2003년도 추계국제학술대회
• /
• pp.23-24
• /
• 2003

The goal of this study is to develop a biomarker used in monitoring abnormal behaviors of Japanese medaka (Oryzias latipes) as a model organism caused by hazardous chemicals. Japanese medaka was treated by copper and fluoranthene of appropriate sublethal concentrations after starvation for 48 hr. In this study we investigated neural toxicity of copper and fluoranthene in Japanese medaka (Oryzias latipes) along with comparative analysis of corresponding behavioral responses. The untreated individuals showed common behavioral characteristics (i.e., smooth and linear movements). Locomotive activity of the fish was monitored using an image processing and automatic data acquisition system. When treated with copper (100 ppb), the fish showed shaking patterns more frequently. As the concentration of copper increased to 1,000 ppb, activity decreased, and the fish showed an erratic movement. The treated with fluoranthene, however, showed stopping and abrupt change of orientation (100 ppb), and severely reduced locomotive activity and enhanced surfacing activity (1,000 ppb).

• 한국환경독성학회:학술대회논문집
• /
• 한국환경독성학회 2003년도 춘계학술대회
• /
• pp.146-147
• /
• 2003

The free-living nematode, Caenorhabditis elegans (C. elegans) has been adopted as a multicellular biosensor of biological toxicity for alkylphenol, organotin compounds and heavy metals. To adopt as a biosensor, suitability to assess must be fulfilledthrough several criteria; the organism must be sensitive to the testing toxicants, easy to manage in the laboratory and available throughout the year. C. elegans widely used as a simple multicellular organism in developmental biology studies and satisfies all these criteria, and its culture conditions, developmental staging, anatomy and genetic properties are well defined. In addition, researchers can take advantage of the worm's short life cycle, low cost and little individual variation. Moreover, genomic sequencing of C. elegans has recently been completed. With these aspectsof the organism, C. elegans become a more potent model organism for basic and applied bioassays.

• 한국환경독성학회:학술대회논문집
• /
• 한국환경독성학회 2003년도 춘계학술대회
• /
• pp.156-157
• /
• 2003

The goal of this study is to develop a biomarker used in monitoring abnormal behaviors of Japanese medaka (Oryzias latipes) as a model organism caused by hazardous chemicals. Japanese medaka was treated under appropriate sublethal concentrations of copper and the fish were subjected to copper treatment after starvation for 48 hr. The untreated individuals showed common behavioral characteristics (i.e., smooth and linear movements with small curvatures) in the movement behaviors.

• Environmental Analysis Health and Toxicology
• /
• 제21권4호
• /
• pp.301-310
• /
• 2006

본 연구에서는 내분비계장애물질로 잘 알려진 Bisphenol A와 Ethynyl estradiol(이하 BPA, EE)이 Chironomus riparius에 미치는 영향을 알아보고자 하였다. 수생생태계에서 Chironomus의 생태학적 중요성을 고려하여 연구한 반수치사농도(LC50),효소 활성, 성장/발달 등의 생화학적, 생리학적 독성에 대한 연구는 이들 물질에 대한 잠재적인 생태학적 중요성을 이해하는데 있어 유용한 정보를 제공할 수 있을 것이다. 연구 결과 BPA와 EE에 노출된 후 C. riparius게서 CAT와 GST활성이 증가하였고, EE에 고농도로 노출된 후 성충까지 충분히 성장하지 못했음을 확인하였다 이러한 결과로부터 C. riparius에서 BPA, EE에 대한 중요한 독성정보를 얻을 수 있었다. 그러므로 앞으로 BPA와 EE의 생화학적 효과와 C. riparitis의 개체수준 이상에서의 생리학적 실험을 통한 검증이 필요할 것이다.