• Mycobiology
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• 제38권4호
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• pp.286-294
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• 2010

Epicoccum purpurascens stain 5615 AUMC was investigated for its biocontrol activity against root rot disease caused by Pythium irregulare. E. purpurascens greenhouse pathogenicity tests using three leguminous plants indicated that the fungus was nonpathogenic under the test conditions. The germination rate of the three species of legume seeds treated with a E. purpurascens homogenate increased significantly compared with the seeds infested with P. irregulare. No root rot symptoms were observed on seeds treated with E. purpurascens, and seedlings appeared more vigorous when compared with the non-treated control. A significant increase in seedling growth parameters (seedling length and fresh and dry weights) was observed in seedlings treated with E. purpurascens compared to pathogen-treated seedlings. Pre-treating the seeds with the bioagent fungus was more efficient for protecting seeds against the root rot disease caused by P. irregulare than waiting for disease dispersal before intervention. To determine whether E. purpurascens produced known anti-fungal compounds, an acetone extract of the fungus was analyzed by gas chromatography mass spectrometry. The extract revealed a high percentage of the cinnamic acid derivative (trimethylsiloxy) cinnamic acid methyl ester. The E. purpurascens isolate grew more rapidly than the P. irregulare pathogen in a dual culture on potato dextrose agar nutrient medium, although the two fungi grew similarly when cultured separately. This result may indicate antagonism via antibiosis or competition.

• The Plant Pathology Journal
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• 제15권6호
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• pp.323-329
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• 1999

Anthracnose of pepper casued by Colletotrichum spphas been a great problems for pepper production in Korea and China. Especially Colletotrichum gloeosporioides was found predominantly over cultivation areas during infection periods and caused severe rots on bath unripe and ripe fruits that resulted in major yield losses. In this study, comparison of Colletrichum spp.isolated from Korea and China in morphology and pathgenicity, and RAPD-PCR analysis were conducted. Based on morphological characteristics, the pathogen isolates, K1 and C1, K2 and C2, and K3 and C3 were identified as Colletotrichum gloeosporioides (G) type, C. gloeosporioides (R) type and C. coccodes, respectively. in pathogenicity test, K1 and C1, and K2 and C2 were found to attack mainly fruits and to be the most virulent among isolates. K3 and C3 were strongly virulent to leaves and seedling. Pathogenicity between Korean and Chinese isolates. K3 and C3 were strongly virulent to leaves and seedling. Pathogenicity between Korean and Chinese isolates did not show any difference. Results of the RAPD-PCR analyses indicate the varying levels of molecular diversity within and between Colletotrichum spp.of Korea and China. The similarities between K1 and C1, K2 and C2, and K3 and C3 were 85.71%, 71.43% and 50.0% respectively.

• 한국작물학회지
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• 제49권1호
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• pp.7-11
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• 2004

Alfalfa (Medicago sativa L.) plants have been reported to be autotoxic as well as allelopathic. Laboratory and greenhouse experiments through petri-dish and pot test were conducted to determine autotoxic effects of alfalfa leaf and soil extracts on the germination or early seedling growth of alfalfa, and to evaluate allelopathic effects of alfalfa leaf residues on alfalfa, barnyard grass, com, eclipta and soybean. Alfalfa seed germination was delayed depending on aqueous extract concentration, with no difference in final germination after 48 hours. Alfalfa root length was more sensitive to the autotoxic chemicals from leaf extracts than was germination or shoot length. Root growth of alfalfa was significantly inhibited at extract concentration of more than 1 g dry tissue/L (g $\textrm{L}^{-1}$). Hypocotyl growth, however, was not affected by all the concentrations of leaf extracts. Soil extracts from 4-yr-old alfalfa stand significantly reduced alfalfa root length by 66%, while soil extracts from 0,1, and 3yr-old stand stimulated root length up to 14-32% over the control. Residue incorporation with dry matters of alfalfa leaf at 100 g $\textrm{kg}^{-1}$ reduced seedling length of several crop and weed species, ranging from 53 to 87% inhibition. Addition of nutrient solution into alfalfa leaf extracts alleviated alfalfa autotoxic effect. This result indicates alfalfa leaf and soil extracts or residues could exert autotoxic as well as allelopathic substances into soil environments during and after establishment.

• The Plant Pathology Journal
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• 제28권1호
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• pp.10-19
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• 2012

This study investigated the distribution of endophytic fungi obtained from the surface sterilized tissues of leaves, stems and roots of chili pepper ($Capsicum$ $annuum$ L.) plants in seedling, flowering and fruiting stages in Korea and their antifungal activity. A total of 481 isolates were recovered and were identified using molecular techniques. Based on rDNA ITS gene sequence and phylogenetic analysis, 21 fungal genera were characterized, belonging to 16 Ascomycota and 5 Basidiomycota. $Penicillium$ in seedling stage, $Fusarium$ in flowering stage, $Colletotrichum$ followed by $Fusarium$, $Alternaria$ and $Xylaria$ in fruiting stage was predominant and $Alternaria$, $Cladosporium$ and $Fusarium$ were common in all growth stages. Among 481 endophytes 90 phenotypes were evaluated for the antimicrobial activity against three major pathogens ($Phytophthora$ $capsici$, $Colletotrichum$ $acutatum$ and $Fusarium$ $oxysporum$) of chili pepper. Among them 16 isolates inhibited the growth of at least one test microorganisms. Three strains showed a broad spectrum antifungal activity and displayed strong inhibition against chili pepper pathogenic fungi.

• Journal of Plant Biology
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• 제22권1_2호
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• pp.15-20
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• 1979

The present study was carried out to investigate the effects of cadmium(Cd), mercury(Hg) and lead(Pb) on the respiration of the germinating seeds. Two kinds of seeds namely, mungbean (Paseolus radiatus L.) and buckwheat (Fagopyrum esculentum M ench) were used for the plant materials. The concentrations of Cd, Hg, and Pb applied for the treatment were 0.1, 1, 10, 100 and 1,000ppm. The germination test was carried out in the dark at 27$^{\circ}C$. Regardless of the kinds of heavy metals, the respiration of the germinating seeds was greatly increased for 24hrs absorbing the heavy metals, and subsequently the respiration was increased average 0.69mg/g.hr.CO2 for mungbean and 0.7mg/g.hr.CO2 for buckwheat. In the lower concentrations of cadmium and lead than 10ppm the germinating rates, seedling concentraitons. The germinating rates, the seedling growth and the respiration were not increased in ay concentrations of mercury, but were decreased with increase of the mercury concenration. The inhibition of seeds respiration by mercury was 3 times higher than by cadmium, and 5 times higher than that by lead. The toxicity of three heavy metals on the respiration was showed from the highest to the lowest in the order of Hg, Cd, and Pb.

• 펄프종이기술
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• 제39권1호
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• pp.30-37
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• 2007

The seed paper was used in farm field recently for a sound young plant. The most of seed paper are made of synthetic non-woven sheet. Therefore, it is very difficult to bio-degrade in soil and is very hard to have some special function, for example keeping herbicide and/or insecticide activity because of its lack of chemical acceptability. The purpose of this research is manufacture of seedling paper which have a function of herbicide activity from waste paper. The fiber properties from waste paper were remarkably improved by fine removal with washing and/or flotation process. The paper-making ability for seed paper was enhanced with enzyme treatment of secondary fibers. The paper for seedling must have a good bio-degradation ability in soils. The absorption amount of chemical like as dithiopyr was increased remarkably in enzyme treated base paper. The embossing treatment of base paper was very effective for seed attachment and chemicals retention. And also, the developed seed paper showed a good penetration property of young root through embossed paper.

• Mycobiology
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• 제51권3호
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• pp.186-194
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• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.

• 한국작물학회지
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• 제60권1호
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• pp.23-28
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• 2015

최근 웰빙 건강식품으로 용도가 다양한 조, 기장, 수수작물의 잡곡육성을 위한 연구개발 및 정책지원이 활발히 추진되고 있다. 조는 생육기간이 90~130일 정도로 짧고 생육온도에 대한 변이가 커서 넓은 지역에 적응할 수 있고 기상재해에 대한 내성도 크다. 본 연구는 남부지방 조 생력재배 기술을 개발하고 육묘방법과 이식방법의 현장적용 가능성을 평가하기 위해 수행하였으며 주요결과는 다음과 같다. 조 육묘방법의 폿트종류별 이식 당시 모소질은 406구, 200구, 162구간에 유의성이 없었으며 본포 활착률은 모두 94~95%를 나타내었다. 수량은 10a당 406구 305 kg > 162구 303 kg > 200구 302 kg을 나타내어 처리간 유의성이 없는 것으로 나타났다. 육묘이식재배시 폿트를 이용할 경우 406구 폿트가 200구 대비 상토 63%, 폿트 50%, 작업시간 18%가 절감되었다. 조 이식방법별 이식 당시 모소질은 이식본수가 적을수록 건조중은 높은 경향이었고 본포 활착률은 모두 95% 이상을 나타내었다. 10a당 수량은 2본 육묘이식 315 kg > 3본 육묘이식 304 kg > 1본 육묘이식 256 kg/10a 순으로 나타났다. 조 육묘이식재배시 폿트종류별 소요경비는 10a당 406구 폿트가 76,230원으로 200구에 비해 40%가 절감되는 것으로 나타나 406구폿트에 2본씩 육묘이식재배 하는 것이 생력화에 적당한 것으로 판단되었다.

• 한국산림과학회지
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• 제110권2호
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• pp.198-209
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• 2021

본 연구는 졸참나무, 물푸레나무, 느티나무를 대상으로 용기 규격이 시설양묘 과정에 질소 양분 특성에 미치는 영향을 구명하기 위해 수행되었다. 16 종류의 용기[4 생육밀도(100, 144, 196, 256본/m²) × 4 용적(220, 300, 380, 460 cm³/구)]에서 생산된 묘목의 질소 양분 특성을 조사·분석하였다. 생육밀도와 용적에 따른 용기묘의 질소 양분 농도 및 함량 변화를 알아보기 위해 이원분산분석 및 다중회귀분석을 이용하였다. 세 수종 모두 용기 규격에 따라 묘목의 질소 양분 특성은 유의적 차이를 보였으며, 생육밀도와 용적 두 요인간의 상호작용이 질소 농도 및 함량에서 확인되었다. 세 수종 모두 질소 함량과 용적은 정의 상관관계를 보였지만, 물푸레나무의 질소 함량은 생육밀도와 부의 상관관계를 나타냈다. 추가적으로 양분벡터분석을 실시하여, 용기 규격에 따른 시비 효과 차이로 양분결핍, 과량집적 등의 양분저장능력이 다르다는 것을 확인하였다. 묘목 질소 함량을 기준으로 다중회귀분석기법을 적용한 결과, 졸참나무는 180~210본/m²과 410~460 cm³/구, 물푸레나무는 100~120본/m²과 350~420 cm³/구, 느티나무는 190~220본/m²과 380~430 cm³/구가 최적 용기 규격으로 최종 도출되었다. 수종별 적정 용기 적용으로 시설양묘 과정에서 양분저장능력이 높은 묘목 생산과 함께 조림 후에도 우수한 생장을 기대할 수 있을 것이다.

• The Plant Pathology Journal
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• 제35권2호
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• pp.112-124
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• 2019

Barley worldwide is affected seriously by Fusarium seedling blight (FSB) and Fusarium head blight (FHB) diseases caused by the Fusarium species. The objective of this study was to facilitate the resistance of hulled and hull-less barley at different growth stages to F. culmorum according to direct parameters: disease rating (DR), fresh weight of leaves and roots, kernel weight per spike, kernel number per spike, plump kernels, and indirect parameters - chlorophyll a fluorescence (CF). Plate assay, greenhouse and field tests were performed on 30 spring barley doubled haploid (DH) lines and their parents infected with Fusarium culmorum. Direct parameters proved that hulled genotypes show less symptoms. Most studied chlorophyll a fluorescence (CF) parameters (apart from DIo/CS - amount of energy dissipated from PSII for laboratory test, TRo/CS - amount of excitation energy trapped in PSII reaction centers, ETo/CS - amount of energy used for electron transport and RC/CS - number of active reaction centres in the state of fully reduced PSII reaction center in field experiment) were significantly affected by F. culmorum infection. In all experiments, hulled genotypes had higher values of CF parameters compared to hull-less ones. Significant correlations were detected between direct and indirect parameters and also between various environments. It was revealed that ABS/CS, TRo/CS, and RC/CS have significant positive correlation in greenhouse test and field experiment. Significant correlations suggest the possibility of applying the CF parameters in selection of barley DH lines resistant to F. culmorum infection.