Colletotrichum Lagenarium Research Articles

Synthesis and antifungal activity of benzamidine derivatives carrying 1,2,3-triazole moieties.

Eighteen novel benzamidine derivatives containing 1,2,3-triazole moieties were synthesized. The in vitro and in vivo fungicidal acitivities of the title compounds and the arylamidine intermediates against Colletotrichum lagenarium and Botrytis cinerea were tested. The synthesized benzamidines exhibited weak antifungal activities in vitro against the tested fungi, but some of the compounds showed excellent activities in vivo to the same strains. Among the compounds tested, 9b showed 79% efficacy in vivo against C. lagenarium at a concentration of 200 μg/mL, and the efficacy of compound 16d (90%) toward the same strain was even superior than that of the commercial fungicide carbendazim (85%).

Synthesis and fungicidal activities of novel benzothiophene-substituted oxime ether strobilurins

Twenty-one novel benzothiophene-substituted oxime ether strobilurins, which employed a benzothiophene group to stabilise the E-styryl group in Enoxastrobin (an unsaturated oxime strobilurin fungicide developed by Shenyang Research Institute of Chemical Industry, China) were designed and synthesised. The biological assay indicated that most compounds exhibited good or excellent fungicidal activities, especially against Colletotrichum lagenarium and Puccinia sorghi Schw. In addition, methyl 3-methoxypropenoate oxime ethers and N-methoxy-carbamic acid methyl esters exhibited good in vivo fungicidal activities against Erysiphe graminis, Colletotrichum lagenarium and Puccinia sorghi Schw. under the tested concentrations. Notably, (E,E)-methyl 3-methoxy-2-(2-((((6-chloro-1-(1H-benzo[b]thien-2-yl)ethylidene)amino)oxy)methyl)phenyl)propenoate (5E) exhibited more potent in vivo fungicidal activities against nearly all of the tested fungi at a concentration of 0.39mg/L compared to Enoxastrobin.

Functional analysis of a melanin biosynthetic gene using RNAi-mediated gene silencing in Rosellinia necatrix

Rosellinia necatrix causes white root rot in a wide range of fruit trees and persists for extended periods as pseudosclerotia on root debris. However, the pathogenesis of this disease has yet to be clarified. The functions of endogeneous target genes have not been determined because of the inefficiency in genetic transformation. In this study, the function of a melanin biosynthetic gene was determined to examine its role in morphology and virulence. A polyketide synthase gene (termed as RnPKS1) in the R. necatrix genome is homologous to the 1,8-dihydroxynaphthalene (DHN) melanin biosynthetic gene of Colletotrichum lagenarium. Melanin-deficient strains of R. necatrix were obtained by RNA interference-mediated knockdown of RnPKS1. The virulence of these strains was not significantly reduced compared with the parental melanin-producing strain. However, knockdown strains failed to develop pseudosclerotia and were degraded sooner in soil than the parental strain. Microscopic observations of albino conidiomata produced by knockdown strains revealed that melanization is involved in synnema integrity. These results suggest that melanin is not necessary for R. necatrix pathogenesis but is involved in survival through morphogenesis. This is the first report on the functional analysis of an endogenous target gene in R. necatrix.

Synthesis, Antifungal Activities and Qualitative Structure Activity Relationship of Carabrone Hydrazone Derivatives as Potential Antifungal Agents

Aimed at developing novel fungicides for relieving the ever-increasing pressure of agricultural production caused by phytopathogenic fungi, 28 new hydrazone derivatives of carabrone, a natural bioactive sesquisterpene, in three types were designed, synthesized and their antifungal activities against Botrytis cinerea and Colletotrichum lagenarium were evaluated. The result revealed that all the derivatives synthesized exhibited considerable antifungal activities in vitro and in vivo, which led to the improved activities for carabrone and its analogues and further confirmed their potential as antifungal agents.

Elevated expression of hydrolases, oxidase, and lyase in susceptible and resistant cucumber cultivars systemically induced with plant growth-promoting fungi against anthracnose

Susceptible and resistant cultivars of cucumber (cv. Suyo and cv. Shogoin fushinari, respectively) were evaluated for induction of systemic resistance by plant growth-promoting fungal isolates Phoma sp. GS8-1 and nonsporulating fungus GU21-2 against Colletotrichum orbiculare. Reduction in anthracnose disease was assessed at regular intervals of 0, 3, 6, and 9 days after challenge inoculation. Activities of endochitinase, β-1,3-endoglucanase, peroxidase (PO), polyphenol oxidase, and phenylalanine ammonia lyase (PAL) were assayed at the above intervals, while the activities of exochitinase and β-1,3-exogluconase were assayed at 9 days after challenge inoculation. The data showed that all the enzymes activities increased in plants treated with plant growth-promoting fungi (PGPF) compared with nontreated plants of both cultivars. The activities of endochitinase and β-1,3-endoglucanase were highly increased in PGPF-induced plants than in nontreated plants of both cultivars at different time points. Activities of PO, polyphenol oxidase, and PAL also increased between 3 and 6 days due to inoculation with PGPF and decreased thereafter. The activity of PAL at 9 days in PGPF-induced plants was at the same level as that of nontreated plants of both cultivars. Results of this investigation suggest that PGPF-induced systemic resistance is associated with not only high increases in the activities of chitinase and β-1,3-gluconases but also other plant defense-related enzymes such as PO, PPO, and PAL. Roles of other mechanisms rather than accumulation of defense-related enzymes in PGPF-mediated induced resistance in susceptible cultivars were demonstrated.

A new prenylated indole derivative from endophytic actinobacteria Streptomyces sp. neau-D50

A new prenylated indole derivative 3-acetonylidene-7-prenylindolin-2-one (1) was isolated from the endophytic actinobacterium Streptomyces sp. neau-D50, together with four known hybrid isoprenoids, 7-isoprenylindole-3-carboxylic acid (2), 3-cyanomethyl-6-prenylindole (3), 6-isoprenylindole-3-carboxylic acid (4) and 7,4′-dihydroxy-5-methoxy-8-(γ,γ-dimethylallyl)-flavanone (5). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with data from the literature. Compounds 1 and 2 demonstrated strong cytotoxic activities against human lung adenocarcinoma cell line A549 with an IC50 of 3.3 and 5.1 μg mL− 1, respectively, which are comparable to that of the positive control doxorubicin (4.2 μg mL− 1). Furthermore, compounds 1–4 exhibited potent antifungal activity against phytopathogenic fungi Colletotrichum orbiculare, Phytophthora capsici, Corynespora cassiicola and Fusarium oxysporum.

Durable and broad-spectrum disease protection measure against airborne phytopathogenic fungi by using the detachment action of gelatinolytic bacteria

We had previously obtained collagenolytic/gelatinolytic bacteria, which degrade the fungal extracellular matrix, to establish a novel biological control measure that inhibits germling adhesion of airborne phytopathogenic fungi on the host plant surface. By using barley-Magnaporthe oryzae pathosystem, Chryseobacterium sp. was most effective biocontrol agents as tested. The selected bacteria were evaluated for durable disease protection against M. oryzae on barley leaves by using chloramphenicol-resistant mutants. Chryseobacterium sp. from the soil was less likely to settle on leaf surfaces. Therefore, we tried to manipulate Chryseobacterium sp. to inhabit the leaf’s surface. The gelatin supplementation dramatically improved the settlement of gelatinolytic bacteria Chryseobacterium sp. from the soil, and the disease protection effect lasted for more than 2weeks on barley. Moreover, exploitation of Chryseobacterium sp. for disease protection was extended against other airborne pathogens, Alternaria alternata Japanese pear pathotype on Japanese pear and Colletotrichum orbiculare on cucumber.

ウリ類炭疽病菌の感染器官分化と病原性発現のダイナミックス

Colletotrichum orbiculare (syn. C. lagenarium) is the causal agent of anthracnose disease on cucurbit plants. This fungus forms dome-shaped, melanized appressoria as a host invasion structure. Strain 104-T (MAFF240422) of C. orbiculare, which was originally isolated from a cucumber plant in 1951 by Dr. Yasumori, Kyoto University, has proven to be an excellent experimental model for the study of fungal pathogenesis and morphogenesis because of its stable pathogenicity and synchronous infection-related morphogenesis. This review considers the discoveries made during 60 years of study on C. orbiculare. In particular, we focus on advances made in the last two decades, which have provided a basis for the molecular analysis not only of fungal morphogenesis, but also of plant–microbe interactions, including plant immunity to adapted and nonadapted Colletotrichum fungi. This substantial body of innovative research was originated by the Phytopathological Society of Japan and represents a major contribution to the international research communities working on plant pathology, plant–microbe interactions, and fungal molecular genetics. This review deals with the past achievements and future prospects in the study of Colletotrichum biology, focusing on the molecular genetics of C. orbiculare with regard to four aspects: (1) metabolic and functional development of infection structures, (2) signaling pathways required for fungal pathogenesis, (3) pathogen-associated molecular patterns (PAMPs) and host basal resistance, and (4) establishment of host specificity.

The Plant Growth-promoting Fungus Penicillium spp. GP15-1 Enhances Growth and Confers Protection against Damping-off and Anthracnose in the Cucumber

Plant growth-promoting fungi (PGPF) have the potential to confer several benefits to plants in terms of growth and protection against pests and pathogens. In the present study, we tested whether a PGPF isolate, Penicillium spp. GP15-1 (derived from zoysiagrass rhizospheres), stimulates growth and disease resistance in the cucumber plant. The use of the barley grain inoculum GP15-1 significantly enhanced root and shoot growth and biomass of cucumber plants. A root colonization study revealed that GP15-1 was a very rapid and efficient root colonizer and was isolated in significantly higher frequencies from the upper root parts than from the middle and lower root parts during the first 14 d of seedling growth. Inoculating the cucumber seedlings with GP15-1 significantly reduced the damping-off disease caused by Rhizoctonia solani, and the disease suppression effects of GP15-1 were considerably influenced by the inoculum potential of both GP15-1 and the pathogen. Treatment with the barley grain inoculum or a cell-free filtrate of GP15-1 increased systemic resistance against leaf infection by the anthracnose pathogen Colletotrichum orbiculare, resulting in a significant decrease in lesion number and size. Molecular and phylogenetic analyses of internal transcribed spacer sequences of the genomic DNA of GP15-1 revealed that the fungal isolate is a strain of either Penicillium neoechinulatum or Penicillium viridicatum.

Biocontrol Activity of Bacillus amyloliquefaciens CNU114001 against Fungal Plant Diseases

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

Characteristic symptoms of melon diseases caused by fungi in south western Nigeria

In a survey of farmers’ fields across four states of south western Nigeria, major diseases of egusi melon were evaluated and symptoms described. Pathogenicity tests of foliage and fruits were conducted in the laboratory and causal pathogens identified. Powdery mildew (Erysiphe cucurbitarum) appeared as round whitish spots on the lower surface which increased in size and later appeared as whitish talcum on the upper surface. Downy mildew (Peronospora cucurbitarum) appeared on the upper surface as small and pale green to yellow angular spot which became chlorotic and shriveled. Alternaria leaf spot (Alternaria cucumerina) appeared as small circular water soaked areas which turned dark brown to black; and Cercospora leaf spot (Cercospora citrullina) appeared as circular spot with white to tan centers having dark margins. Foliar spots which began as small yellowish water- soaked areas on the veins that later turned circular, dried up, broke and became shattered were symptoms observed for the Anthracnose disease (Colletotrichum lagenarium). Fruit anthracnose started as small, circular, black, sunken canker with raised margin. Leaf blight, stem blight and fruit rot (Didymella bryoaniae) disease symptoms were observed on leaves, stems and fruits respectively. Leaf symptoms began as light brown, irregular spots surrounded by yellow borders that developed from the tip of the leaves and gradually progressed backwards. Brown lesions were observed on the stem which split open and turned dark. Lesions observed on fruits appeared as small, almost circular water- soaked areas which enlarged, resulting in dark, firm and leathery depressed areas. Symptoms of vine wilt were observed as elongated brown lesions which developed on stems near the crown and extended as long, narrow, brown streaks causing stem to completely wilt. Wet rot of flower and fruit (Choanephora cucurbitarum) appeared as characteristic fungus growth resembling numerous pins stuck in a pin-cushion on the infected surface. The study will help to bridge the gap of information on the characteristic symptoms and causal pathogens of melon diseases in south western Nigeria Key words: “Egusi” melon, south western, field diseases, symptoms.

Design, synthesis, antifungal activities and 3D-QSAR of new N,N'-diacylhydrazines containing 2,4-dichlorophenoxy moiety.

A series of new N,N′-diacylhydrazine derivatives were designed and synthesized. Their structures were verified by 1H-NMR, mass spectra (MS) and elemental analysis. The antifungal activities of these N,N′-diacylhydrazines were evaluated. The bioassay results showed that most of these N,N′-diacylhydrazines showed excellent antifungal activities against Cladosporium cucumerinum, Corynespora cassiicola, Sclerotinia sclerotiorum, Erysiphe cichoracearum, and Colletotrichum orbiculare in vivo. The half maximal effective concentration (EC50) of one of the compounds was also determined, and found to be comparable with a commercial drug. To further investigate the structure–activity relationship, comparative molecular field analysis (CoMFA) was performed on the basis of antifungal activity data. Both the steric and electronic field distributions of CoMFA are in good agreement in this study.

Antimicrobial Constituents of the Leaves of Mikania micrantha H. B. K

BackgroundTo isolate plant-derived compounds with antimicrobial activity from the leaves of Mikania micrantha, to determine the compounds configuration, and to evaluate their antimicrobial activity against eight plant pathogenic fungi (Exserohilum turcicum, Colletotrichum lagenarium, Pseudoperonispora cubensis, Botrytis cirerea, Rhizoctonia solani, Phytophthora parasitica, Fusarium solani, and Pythium aphanidermatum,) and four plant pathogenic bacteria (gram negative bacteria: Ralstonia dolaanacearum, Xanthomonas oryzae pv. Oryzae, Xanthomonas Campestris pv. Vesicatoria, and Xanthomonas campestris pv. Citri), and four bacteria (gram positive bacteria: Staphyloccocus aureus, Bacillus subtilis, Micrococcus luteus, and Bacillus cereus).Methods and ResultsAntimicrobial constituents of the leaves of M. micrantha were isolated using bioactivity- guided fractionation. The antifungal activity of the isolated compounds was evaluated by the inhibit hypha growth method and inhibit spore germination method. Characterization of antibacterial activity was carried out using the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs). MIC and MBC were determined by the broth microdilution method. Six compounds – deoxymikanolide, scandenolide, dihydroscandenolide, mikanolide, dihydromikanolide, and m - methoxy benzoic acid – have been isolated from leaves of Mikania micrantha H. B. K. Deoxymikanolide, scandenolide, and dihydroscandenolide were new compounds. The result of bioassay showed that all of isolated compounds were effective against tested strains and deoxymikanolide showed the strongest activity.Conclusions and SignificanceThe leaves of M. micrantha may be a promising source in the search for new antimicrobial drugs due to its efficacy and the broadest range. Meanwhile, adverse impact of M. micrantha will be eliminated.

Essential Oil from Inula britannica Extraction with SF-CO2 and Its Antifungal Activity

The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide (SF-CO2) for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogenic fungi for its potential application as botanical fungicide. The effects of factors, including extraction temperature, extraction pressure, SF-CO2 flow rate, flower powder size, and time on the essential oil yield were studied using the single factor experiment. An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield. Adopting the optimum conditions, the maximum yield reached 10.01% at 40°C temperature, 30 MPa pressure, 60 mesh flower powder size, 20 L h−1 SF-CO2 flow rate, and 90 min extraction time. The antifungal activities of I. britannica essential oil using the SF-CO2 against the most important plant pathogenic fungi were also examined through in vitro and in vivo tests. Sixteen plant pathogenic fungi were inhibited to varying degrees at 1 mg mL−1 concentration of the essential oil. The mycelial growth of Gaeumannomyces graminis var. tritici was completely inhibited. The radial growths of Phytophthora capsici and Fusarium monilifome were also inhibited by 83.76 and 64.69%, respectively. In addition, the essential oil can inhibit the spore germination of Fusarium oxysporum f. sp. Vasinfectum, Phytophthora capsici, Colletotrichum orbiculare, and Pyricularia grisea, and the corresponding inhibition rates were 98.26, 96.54, 87.89, and 87.35% respectively. The present study has demonstrated that the essential oil of I. britannica flowers extracted through the SF-CO2 technique is one potential and promising antifungal agent that can be used as botanical fungicide to protect crops.

Disease suppression and growth promotion in cucumbers induced by integrating PGPR agent Bacillus subtilis strain B4 and chemical elicitor ASM

This study describes the combined use of the plant growth-promoting rhizobacteria (PGPR) agent, Bacillus subtilis strain B4 (B4) and acibenzolar-S-methyl [benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester; ASM], a commercial systemic acquired resistance (SAR) elicitor to increase the efficacy of the control of anthracnose disease in cucumber plants caused by Colletotrichum orbiculare (Berk. & Mont.) Arx. We evaluated populations of B4 bacterial cells and found them to be more numerous when cultured in a growth medium amended with ASM than when cultured alone. A spectrophotometer analysis revealed an increase in a broad range of compounds found in the culture filtrate from B4 + ASM compared with filtrate from B4 alone. An increased l-tryptophan utilization in the production of indole acetic acid (IAA) was observed when B4 was combined with ASM relative to when B4 was used alone. The application of B4 combined with ASM resulted in an additive effect, eliciting growth promotion and systemic resistance against anthracnose infection in cucumber plants. There was an increased growth as measured by plant height, leaf length, and leaf width for the combined application when compared to the individual applications of B4 or ASM or untreated control. Anthracnose disease in cucumbers was significantly suppressed by application of the combined B4 and ASM when compared with the individual applications. Thus, the integrated use of the chemical elicitor, ASM and the PGPR agent B4 might serve as an alternative management strategy against anthracnose disease in cucumbers.

Synthesis, characterization, and antifungal activity of novel inulin derivatives with chlorinated benzene

A group of novel inulin derivatives containing benzene or chlorinated benzene were synthesized by reaction of chloracetyl inulin (CAIL) with the Schiff bases of 4-amino-pyridine, including (2-pyridyl)acetyl inulin chloride (PAIL), 2-[4-(2-chlorobenzylideneamino)-pyridyl]acetyl inulin chloride (2CPAIL), 2-[4-(4-chlorobenzylideneamino)-pyridyl]acetyl inulin chloride (4CPAIL), and 2-[4-(2,4-dichlorobenzylideneamino)-pyridyl]acetyl inulin chloride (2,4DCPAIL). Their antifungal activity against three kinds of phytopathogens was estimated by hypha measurement in vitro. Of all the synthesized chitosan derivatives, 2,4DCPAIL inhibited the growth of the tested phytopathogens with inhibitory indices of 67%, 47%, and 43% against Colletotrichum lagenarium (Pass) Ell.et halst, Phomopsis asparagi (Sacc.) Bubak and Fusarium oxysporum (schl.) F.sp. niveum (F. oxysporum) respectively at 1.0mg/mL. The results indicate that all the inulin derivatives have better antifungal activity than inulin, and the inhibitory index is affected by the chlorine atom grafted to the inulin derivatives.

Differences in the Induction of Defence Responses in Resistant and Susceptible Muskmelon Plants Infected with Colletotrichum lagenarium

Defence reactions occurring in resistant (cv. Gankezaomi) and susceptible (cv. Ganmibao) muskmelon leaves were investigated after inoculating with Colletotrichum lagenarium. Lesion restriction in resistant cultivars was associated with the accumulation of hydrogen peroxide (H2O2). The activity of antioxidants catalase (CAT) and peroxidase (POD) significantly increased in both cultivars after inoculation, while levels of both CAT and POD activity were significantly higher in the resistant cultivar. Ascorbate peroxidase (APX) increased in both cultivars after inoculation, and level of APX activity was significantly higher in the resistant cultivar. Glutathione reductase (GR) activity significantly increased in both cultivars following inoculation, but was higher in the resistant cultivar, resulting in higher levels of ascorbic acid (AsA) and reduced glutathione (GSH). Phenylalanine ammonia lyase (PAL) significantly increased in inoculated leaves of both cultivars, resulting in higher levels of total phenolic compounds and flavonoids. The pathogenesis-related proteins chitinase (CHT) and β-1, 3-glucanase (GLU) significantly increased following inoculation with higher activity in the resistant cultivar. These findings show that resistance of muskmelon plants against C. lagenarium is associated with the rapid accumulation of H2O2, resulting in altered cellular redox status, accumulation of pathogenesis-related proteins, activation of phenylpropanoid pathway to accumulation of phenolic compounds and flavonoids.

In Vitro Control Of Five Pathogenic Fungi Isolated From Groundnut (Arachis Hypogaea L.)

Efficacy of five plant extracts namely, Allium cepa, Allium sativum, Azadirachta indica, Tagetes patula and Zingiber officinale was evaluated against five pathogenic species of fungi isolated from groundnut in vitro. These were Colletotrichum acutatum, Colletotrichum dematium, Colletotrichum orbiculare, Colletotrichum sp. and Fusarium semitectum. Colony growth of C. dematium was completely checked with Allium sativum at all the concentrations used (5, 10 and 20 %). Similarly A. cepa, A. sativum and A. indica completely inhibited the colony growth of C. orbiculare at the same concentrations used. T. patula and Z. officinale also showed appreciable inhibition in colony growth of five species of fungi at 10 and 20% concentrations. J. Asiat. Soc. Bangladesh, Sci. 39(1): 27-33, June 2013 DOI: http://dx.doi.org/10.3329/jasbs.v39i1.16030

The Colletotrichum orbiculare species complex: Important pathogens of field crops and weeds

Colletotrichum orbiculare causes anthracnose of Cucurbitaceae and is phylogenetically closely related to pathogens of several other herbaceous hosts belonging to the Asteraceae, Fabaceae and Malvaceae. Most of them are known for their hemibiotrophic infection strategy and as destructive pathogens either of field crops or weeds. In order to study the phylogenetic relationships of these fungi, a multilocus analysis (ITS, GAPDH, CHS-1, HIS3, ACT, TUB2, GS) of 42 strains of C. orbiculare and related species was conducted. The analysis resulted in nine clades that confirmed the four species previously known as belonging to this species complex, C. lindemuthianum, C. malvarum, C. orbiculare and C. trifolii, and recognised four new species from weeds, namely C. bidentis, C. sidae, C. spinosum and C. tebeestii. The name C. orbiculare itself is widely used in plant pathology and science, but is invalid according to current nomenclatural rules. Therefore we described a new species with the same epithet and a type specimen that agrees with our current understanding of this species, and is linked to a living culture. Following the recent epitypification of C. lindemuthianum, we chose appropriate specimens with associated strains to serve as epitypes of C. malvarum and C. trifolii, and selected an authentic specimen of C. trifolii as lectotype.

탄저병(Colletotrichum orbiculare)에 대한 박과작물의 저항성

Colletotrichum orbiculare에 의한 탄저병은 오이, 수박 및 멜론 등의 박과작물에 전세계적으로 발생하여 많은 피해를 주고 있다. 본 연구에서는 시판 중인 박과작물 112개 품종의 탄저병에 대한 저항성 정도를 조사하였다. 각 품종의 2-3엽기 유묘에 C. orbiculare KACC 40809의 포자 농도가 4.0 C <TEX>$40^5spores/mL$</TEX>인 포자현탁액을 분무하여 접종하였다. 실험한 36개 오이 품종 중 '아시아스트라이크', '통일백다다기', '대선', '청록맛짱', '녹야청청' 및 '아시아노각' 등 6품종은 중도저항성을 나타내었으며, 나머지 품종들은 감수성을 보였다. 멜론 및 참외 33개 품종과 수박 4개 품종들은 C. orbiculare에 대하여 모두 감수성을 나타내었다. 이와 달리 호박 품종들은 실험한 다른 박과작물에 비하여 낮은 감수성을 보였다. 호박 17개 품종 중 '감미락단호박'과 '텃밭풋호박'은 저항성을, 12개 품종은 중도저항성을 나타냈다. 박과작물을 위한 대목 22개 품종 중 '쯔야까EX', '눈부셔', '유니온', 'RS111', '강근토좌', '황제토좌', 'NO.8', '신토좌', '불패토좌' 및 '뉴타입' 등 10개 품종은 저항성을 보였고, 4개 품종은 중도저항성을 나타냈다. 이상의 결과로부터 선발된 저항성 품종들은 박과작물 탄저병 저항성 육종을 위한 유전자원으로 이용될 수 있으리라 생각되었다. Anthracnose disease caused by Colletotrichum orbiculare, induces severe damage to cucurbits worldwide. Resistance of 112 commercial cultivars of cucurbits to C. orbiculare was evaluated. Seedlings of each cultivar at 2- to 3-leaf stage were inoculated with C. orbiculare KACC 40809 by spraying spore suspension of the fungus at a concentration of <TEX>$4.0{\times}10^5$</TEX> spores/mL. Among the 36 cultivars of cucumber, 'Asiastrike', 'Tongilbaedadagi', 'Daeseon', 'Cheongrokmatjjang', 'Nokyacheongcheong', and 'Asianogak' were moderately resistant and the others were susceptible. All the tested cultivars of melon (33) and watermelon (4) showed highly susceptible response to C. orbiculare. On the other hand, the squash cultivars (17) represented less susceptibility to the fungus than the other cucurbits. Of the squash cultivars, 'Gammirak' and 'Teotbat' were resistant and 12 cultivars were moderately resistant. Among the rootstocks for cucurbits, ten cultivars including 'JjeuyakaEX', 'Nunbusyeo', 'Union', 'RS111', 'Ganggeuntoza', 'Hwangjaetoza', 'NO.8', 'Shintoza', 'Bulpaetoza', and 'Newtype' showed high resistance to the anthracnose pathogen. From the results, the resistant cultivars could be used as sources of resistance to cucurbits anthracnose (C. orbiculare) in the future breeding programs.