Cladosporium Cucumerinum Research Articles

Fungal membrane determinants affecting sensitivity to antifungal cyclic lipopeptides from Bacillus spp.

Bacillus spp. produce numerous antimicrobial metabolites. Among these metabolites, cyclic lipopeptides (CLP) including fengycins, iturins, and surfactins are known to have varying antifungal activity against phytopathogenic fungi. The differential activities of CLP have been attributed to diverse mechanisms of action on fungal membranes. However, the precise biochemical determinants driving their antifungal modes of action have not been conclusively identified. In this study, three plant pathogenic fungi of varying lipopeptide sensitivities, Alternaria solani, Cladosporium cucumerinum, and Fusarium sambucinum, were studied to determine how their cell membrane lipid compositions may confer sensitivity and/or tolerance to fengycin, iturin, and surfactin. Results indicated that sensitivity to all three lipopeptides correlated with lower ergosterol content and elevated phospholipid fatty acid unsaturation. Fungal sensitivity to surfactin was also notably different than fengycin and iturin, as surfactin was influenced more by lower phosphatidylethanolamine amounts, higher levels of phosphatidylinositol, and less by phospholipid fatty acyl chain length. Results from this study provide insight into the fungal membrane composition of A. solani, F. sambucinum, and C. cucumerinum and the specific membrane characteristics influencing the antifungal effectiveness of fengycin, iturin, and surfactin. Understanding of these determinants should enable more accurate prediction of sensitivity-tolerance outcomes for other fungal species exposed to these important CLP.

Effects of fire smoke on soil microorganisms: results of a modelling experiment

ABSTRACT Wildfires are widespread and have major effects on ecosystems. The sensitivity of soil microorganisms to smoke was studied in experimental conditions using smoke generated from burning pine sawdust. High concentrations of toxicants such as NO (40 mg/m3), NO2 (60 mg/m3), CO (3570 mg/m3), C2H4O (241 mg/m3), CH2O (9.5 mg/m3), C6H6O (4.4 mg/m3), and C6H14 (238 mg/m3) were measured in the smoke. Reduced abundance of Azotobacter chroococcum by 9–62% and of microscopic fungi by 25–57% was found when the soil was treated with smoke for 30–120 min. The abundance of soil microorganisms after exposure to smoke depended on time. Several species of soil fungi (Fusarium oxysporum, Venturia inaequalis, Fusarium moniliforme, Fusarium graminearum, Cladosporium cucumerinum, Penicillium chrysogenum, Rhodotorula rubra, Lipomyces starkeyi), and bacteria (Acinetobacter calcoaceticus, Streptomyces violaceus, Kocuria rosea) were studied. The lowest smoke exposure time at which growth inhibition was registered was 1–5 min. The effect of smoke on the enzymatic activity of Haplic Chernozem soils was also evaluated. Catalase activity was found to decrease by 25%, and peroxidase and polyphenol oxidase by 15% and 33%, respectively. High smoke toxicity contributed to changes in microbial abundance and enzymatic activity.

Genome Sequence Resource of Cladosporium velox Strain C4 Causing Cotton Boll Disease in Xinjiang, China.

Cladosporium spp., as one of the largest and most heterogeneous genera of hyphomycetes, are widely distributed worldwide. This genus is usually adaptable to a wide variety of extreme environments. However, only 11 genomes of Cladosporium genus have been publicly released. From 2017, we found for the first time that Cladosporium velox could cause cotton boll disease and lead to stiffness and cracking boll in Xinjiang, China. Herein, we provide a high-quality reference genome for the C. velox strain C4 isolated from cotton boll in Xinjiang, China. The genome size and encoding gene number of the C. velox strain C4 and C. cucumerinum strain CCNX2, which was recently released and caused the cucumber scab, showed minor differences. This resource will contribute to future research that aims to elucidate the genetic basis of C. velox pathogenicity and could expand our knowledge of Cladosporium spp. genomic characteristics that will be valuable for the development of Cladosporium disease control measures.

Новый пчелоопыляемый гибрид огурца селекции ФГБНУ ФНЦО Храбрец F1

Cucumber is an economically important vegetable crop, which grown in the open field and in various cultivation facilities; at the moment, the range of cucumber hybrids is large, but not all of them sufficiently meet the requirements of the market. The creation of competitive high-yielding hybrids that meet the requirements of the modern market with complex disease resistance for greenhouses, plastic shelters and open ground is the main focus of breeding research on cucumber culture. One of the important areas of breeding work with cucumber culture is the creation of highly productive bee-pollinated hybrids for open ground, temporary shelters and plastic shelters. Preference is given to hybrids of a mixed type of flowering with a high saturation of female flowers, resistant to major diseases and unfavorable growing conditions, with short tuberculate fruits of a universal type of use. As a result of the research, a heterotic hybrid Khrabrets F1 was obtained and included in the State Register of Breeding Achievements approved for use in 2022. Khrabrets F1 an early ripe bee-pollinated hybrid for growing in greenhouses, under temporary shelters and in open ground. The period from germination to the beginning of fruiting is 42-44 days. Fruit is 10-12 cm, cylindrical, medium-tuberous, white-spiked, saturated green color. Hybrid Khrabrets F1 has very good taste. The hybrid has resistant to Cladosporium cucumerinum (Ccu), powdery mildew (Px), and tolerant to pseudoperonospora cubensis (Pcu). A hybrid of universal purpose, intended for fresh consumption, pickling and canning.

Applying meta-data of soybean grain in origin trace and quarantine inspection

Soybean and derived products are among the most important food for both humans and animals. China is the world's largest importer of soybeans, with more than 100 million tons of annual imports, mainly from the United States of America (US), Brazil, and Argentina. However, there have been limited studies on the microbiota associated with imported soybean grains. Here, we reveal the soybean microbiota using amplicon sequencing based on samples from four countries on three continents of North America (US), South America (Argentina, Brazil), and Asia (China). Our results showed that the soybean-associated microbiota from different continents significantly separated, presenting strong geographic variations. The core microbial taxa and geographically specified taxa were defined, with Alternaria, Enterobacter, Plectosphaerella, Stenotrophomanas, and Xeromyces defined as the core microbiota for soybean from Asia; Amanita, Aspergillus, Fusarium, Nigrospora, Herbiconiux, Pseudomonas, Saccharopolyspora, and Schumannella from North America; and Bradyrhizobium, Colletotrichum, Filobasidium, Phialosimplex, Mycosphaerella, Septoria, Sphingomonas, and Weissalla, from South America. In addition, we build the Random Forest (RF) model to predict the source of imported soybean grains. We could accurately predict the original countries of imported soybean grains within the RF prediction models, with accuracies greater than 95 %. We constructed a database of soybean-related quarantine pathogens using full-length sequences of fungal ITS region and bacterial 16S rDNA region. Two phytopathogenic fungi, Diaporthe caulivora and Cladosporium cucumerinum, listed in the Chinese quarantine catalog, were intercepted through metabarcoding sequencing. The former was further confirmed using an available national standard protocol of qPCR diagnosis. In summary, our NGS-based approach revealed the microbiota associated with soybeans. It could provide comprehensive information and valuable method on the trace the origin of soybean and detection of quarantine pathogens at Customs and departments of inspection and quarantine.

Survey of cucumber target spot, in vitro sporulation and aggressiveness of Corynespora cassiicola

The objective was to carry out a survey of the occurrence of the target spot (Corynespora cassiicola) in cucumber crops in São Paulo State; to evaluate culture media for sporulation of the pathogen and the aggressiveness of isolates of the pathogen in cucumber plants. The target spot was found in nine municipalities, being the main disease in seven of the ten municipalities sampled, with leaf incidence above 50%, showing that the target spot of cucumber is widely distributed in São Paulo State. Other diseases found less frequently were scabies (Cladosporium cucumerinum), alternaria spot (Alternaria cucumerina), cercospora spot (Cercospora citrullina) and downy mildew (Pseudoperonospora cubensis), predominant in samples from one or two municipalities, but also found in most municipalities. The zoned spot (Leandria momordicae) was found to have a low incidence, in samples from three municipalities and with an incidence lower than 20%. Greater sporulation of the pathogen occurred in tomato juice and oat flour media, without scraping the surface of the colony maintained for 16 days at 25ºC, under continuous fluorescent light. The germination of C. cassiicola isolates used in the aggressiveness test was between 82.8 and 95.5%, with the 50 isolates separated into two groups. The isolates were separated into four groups within the range of 3.1 to 22.3% in severity, after ten days of inoculation of the pathogen, showing the genetic variability within the species, which should be considered in management studies, such as genetic improvement.

Evaluation of Antifungal Activity of Some Plant Extractives

In vitro antifungal activity of thirty two extractives of seven plants obtained using hexane, ethyl acetate and methanol were tested against the mycelial growth of Colletotrichum gloeosporioides. Among these extractives, ethyl acetate extractives of onion seeds, chilli seeds and chilli pericarps and methanol extractives of chilli seeds and chilli pericarps exhibited more than 20 % mycelial growth inhibition at a concentration of 0.5 % level. Methanol extractives of Solanum viarum berries and ethyl acetate extractive of soybean leaves exhibited more than 20 % mycelial growth inhibition at a concentration of 1.0 % level. Thin layer chromatographic bioautography showed that hexane and ethyl acetate extractives of onion seeds, chilli seeds and chilli pericarps exhibited spore germination inhibition of Cladosporium cucumerinum at a dose of 1.0 mg.

Fungi of quarantine concern for China I: Dothideomycetes.

The current list of Chinese quarantine pests includes 130 fungal species. However, recent changes in the taxonomy of fungi following the one fungus = one name initiative and the implementation of DNA phylogeny in taxonomic revisions, resulted in many changes of these species names, necessitating an update of the current list. In addition, many quarantine fungi lack modern morphological descriptions and authentic DNA sequences, posing significant challenges for the development of diagnostic protocols. The aim of the present study was to review the taxonomy and names of the 33 Chinese quarantine fungi in Dothideomycetes, and provide reliable DNA barcodes to facilitate rapid identification. Of these, 23 names were updated according to the single name nomenclature system, including one new combination, namely Cophinforma tumefaciens comb. nov. (syn. Sphaeropsis tumefaciens). On the basis of phylogenetic analyses and morphological comparisons, a new genus Xenosphaeropsis is introduced to accommodate the monotypic species Xenosphaeropsis pyriputrescens comb. nov. (syn. Sphaeropsis pyriputrescens), the causal agent of a post-harvest disease of pears. Furthermore, four lectotypes (Ascochyta petroselini, Mycosphaerella ligulicola, Physalospora laricina, Sphaeria lingam), three epitypes (Ascochyta petroselini, Phoma lycopersici, Sphaeria lingam), and two neotypes (Ascochyta pinodella, Deuterophoma tracheiphila) are designated to stabilise the use of these names. A further four reference strains are introduced for Cophinforma tumefaciens, Helminthosporium solani, Mycocentrospora acerina, and Septoria linicola. In addition, to assist future studies on these important pathogens, we sequenced and assembled whole genomes for 17 species, including Alternaria triticina, Boeremia foveata, B. lycopersici, Cladosporium cucumerinum, Didymella glomerata, Didymella pinodella, Diplodia mutila, Helminthosporium solani, Mycocentrospora acerina, Neofusicoccum laricinum, Parastagonospora pseudonodorum, Plenodomus libanotidis, Plenodomus lingam, Plenodomus tracheiphilus, Septoria petroselini, Stagonosporopsis chrysanthemi, and Xenosphaeropsis pyriputrescens. Citation: Zhao P, Crous PW, Hou LW, et al. 2021. Fungi of quarantine concern for China I: Dothideomycetes. Persoonia 47: 45-105. https://doi.org/10.3767/persoonia.2021.47.02.

Peptidyl prolyl cis/trans isomerase from Pseudomonas fluorescens encapsulated into biodegradable natural polymers: A potential plant protection agent inducing plant resistance to fungal pathogens

Intensive use of pesticides causes pollution of terrestrial and water ecosystems negatively influencing on the biodiversity and human health. Use of bioactive compounds, such as elicitors, able to boost non-specific plant immunity, is a promising alternative to chemical treatments of crops. MF3, a protein from Pseudomonas fluorescens , is able to induce resistance in various crops thus protecting them from a range of plant pathogens, but can be destroyed under field conditions by UV radiation and proteolytic enzymes of plant and microbial origin. MF3 encapsulation in biodegradable polymers, such as poly-3-hydroxybutyrate (PHB) and sodium alginate (ALG) has been shown earlier to shield it against adverse external factors. In this study, we examined the protecting efficiency of both MF3 complexes on three model plant–pathogen systems: “wheat – Parastagonospora nodorum ” (1), “rice – Magnaporthe oryzae ” (2), and “cucumber – Cladosporium cucumerinum ” (3). Both MF3-ALG and MF3-PHB complexes demonstrated a significant disease suppression level varying between 55–80 and 40–60 % in the models 1 and 3, respectively; in the model 2, they completely blocked disease development. A significant protective activity of ALG alone was observed in all three models. For the models 1 and 2, a synergistic interaction between MF3 and ALG in relation to the disease suppression was validated. In several cases (free and encapsulated MF3 in the model 1 and MF3-ALG complex in the model 2), a possible translaminar protective activity was shown. The obtained results confirmed a principal possibility to develop environmentally safe biopesticides based on the MF3 encapsulated in PHB or ALG. • MF3 protein encapsulation in sodium alginate and 3-PHB did not influence on its protecting activity. • Encapsulated MF3 protein improves resistance of wheat, rice, and cucumber against some fungi. • MF3 protein encapsulated in sodium alginate completely protect rice against rice blast. • MF3 and sodium alginate synergistically interacts in two model plant-pathogen systems. • For some cases, MF3 possesses a possible translaminar protecting activity.

Fungi of quarantine concern for China I: Dothideomycetes.

The current list of Chinese quarantine pests includes 130 fungal species. However, recent changes in the taxonomy of fungi following the one fungus = one name initiative and the implementation of DNA phylogeny in taxonomic revisions, resulted in many changes of these species names, necessitating an update of the current list. In addition, many quarantine fungi lack modern morphological descriptions and authentic DNA sequences, posing significant challenges for the development of diagnostic protocols. The aim of the present study was to review the taxonomy and names of the 33 Chinese quarantine fungi in Dothideomycetes, and provide reliable DNA barcodes to facilitate rapid identification. Of these, 23 names were updated according to the single name nomenclature system, including one new combination, namely Cophinforma tumefaciens comb. nov. (syn. Sphaeropsis tumefaciens). On the basis of phylogenetic analyses and morphological comparisons, a new genus Xenosphaeropsis is introduced to accommodate the monotypic species Xenosphaeropsis pyriputrescens comb. nov. (syn. Sphaeropsis pyriputrescens), the causal agent of a post-harvest disease of pears. Furthermore, four lectotypes (Ascochyta petroselini, Mycosphaerella ligulicola, Physalospora laricina, Sphaeria lingam), three epitypes (Ascochyta petroselini, Phoma lycopersici, Sphaeria lingam), and two neotypes (Ascochyta pinodella, Deuterophoma tracheiphila) are designated to stabilise the use of these names. A further four reference strains are introduced for Cophinforma tumefaciens, Helminthosporium solani, Mycocentrospora acerina, and Septoria linicola. In addition, to assist future studies on these important pathogens, we sequenced and assembled whole genomes for 17 species, including Alternaria triticina, Boeremia foveata, B. lycopersici, Cladosporium cucumerinum, Didymella glomerata, Didymella pinodella, Diplodia mutila, Helminthosporium solani, Mycocentrospora acerina, Neofusicoccum laricinum, Parastagonospora pseudonodorum, Plenodomus libanotidis, Plenodomus lingam, Plenodomus tracheiphilus, Septoria petroselini, Stagonosporopsis chrysanthemi, and Xenosphaeropsis pyriputrescens. Citation: Zhao P, Crous PW, Hou LW, et al. 2021. Fungi of quarantine concern for China I: Dothideomycetes. Persoonia 47: 45-105. https://doi.org/10.3767/persoonia.2021.47.02.

Identification of SCAR markers linked to the Foc gene governing resistance to Fusarium oxysporum f. sp. cucumerinum in cucumber cv. SMR-18

Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum (FOC) is an important soil-borne disease of cucumber in several parts of the world. In this study, we employed amplified fragment length polymorphic (AFLP) markers along with bulked segregant analysis (BSA), in order to identify structural markers linked to the Foc gene that governs resistance to FOC races 1, 2 and 3 in the resistant cv. SMR-18. From the four AFLP markers originally identified at the BSA level, only one (E12M50134 + T) maintained a linkage in coupling phase against the F2 mapping population. AFLP-mediated sequencing was employed in order to ensure the identification and sequencing of the truly linked AFLP fragment. This AFLP marker mapped at a distance of 6.0 cM from the Foc resistance locus and was successfully converted into two sequence-characterized amplified region (SCAR) co-dominant markers. SCAR marker SCE12M50B produced a single fragment linked to Foc and behaved as a dominant marker, while SCE12M50A amplified one strong fragment linked to Foc in parallel with a second faint fragment. The SCE12M50B fragment physically maps on chromosome 2 and lies 1.64 Mb (7,0 cM) away from the microsatellite marker SSR03084, which is closely linked to Ccu locus that controls resistance to scab, caused by Cladosporium cucumerinum in cv. SMR-18.

Inhibitors of Antioxidant Enzymes Systemically Protect Cucumber Plants from Scab

The study is aimed at the induction of systemic disease resistance by a local oxidative burst caused by inhibition of plant antioxidant enzymes. A possible involvement of ROS was ascertained. Inhibitors of superoxide dismutase and catalase, respectively, diethyldithiocarbamate (DDC) and aminotriazole (AT) were applied to the fist (local) true leaf of cucumber seedlings (Cucumis sativus L.). When the second and third (systemic) leaves developed, they were inoculated with spores of the virulent fungus Cladosporium cucumerinum Ell. et Arth. causing cucurbit scab. The inhibitors at concentrations nontoxic to leaves or spores greatly reduced the disease symptoms on the systemic leaves. The inhibition of both enzymes was confirmed, and increased superoxide production was found in the chemically treated local leaf. In case of a treatment with water, diffusates of the healthy systemic leaves stimulated spore germination, and those of infected systemic leaves were ineffective. Treatment of the local leaf with any compound systemically suppressed the aforementioned stimulation in the healthy counterpart and provided fungitoxicity in the infected one. Both antifungal effects were abolished by diffusate boiling, suggesting protein involvement. Meanwhile, the effects were insensitive to antioxidants and, apparently, independent of reactive oxygen. DDC and AT did not promote salicylic acid accumulation in infected systemic leaves; presumably, the disease control did not represent systemic acquired resistance. It is suggested that both inhibitors induce some kind of systemic resistance through the local oxidative burst caused by inhibition of antioxidant enzymes. The systemic implementation of the resistance may include antifungal effects.

Effect of Some Bioagents on Cladosporium cucumerinum Causing Cladosporium Leaf Spot: A New Challenge in Watermelon Production in Egypt.

Seven isolates of bioagents, Trichoderma harzianum, Pseudomonas fluorescens, Bacillus subtilis, Anabena oryzae, Nostoc muscorum, Chaetomium globosum and Gliocladium catenulatum were used to control cladosporium leaf spot. Nostoc muscorum mixed with Pseudomonas fluorescens successfully reduced the growth and spore germination of Cladosporium cucumerinum. The potentially of the bioagents significantly reduced the cladosporium leaf spot disease incidence and inhibiting its progress when used each alone or as mixtures under field conditions. The bioagents generally improved the watermelon plants and significantly increased the plant height, number of branches, fruit numbers and fruits weight due to treatment with the tested bioagents either each alone or in mixture compared to the untreated control.

Monoxenic rearing of Ditylenchus weischeri and D. dipsaci and microplot examination of the host suitability of yellow pea to D. weischeri

Ditylenchus weischeri was recently reported in the provinces of Manitoba and Saskatchewan, Canada. Populations of D. weischeri from creeping thistle (Cirsium arvense L.) in Manitoba and D. dipsaci from garlic (Allium cepa L.) in Ontario were examined for their potential to grow on callused carrot (Daucus carota subsp. sativus) disks, alfalfa (Medi-<br /> cago sativa L.) and creeping thistle callus tissues, and pure cultures of eight fungal species, Botrytis cinerea, Fusarium solani, Rhizoctonia solani, Verticillium dahliae, Sclerotinia sclerotiorum, Cladosporium cucumerinum, Colletotrichum gloeosporioides, and Chaetomium spp. Ditylenchus weischeri and D. dipsaci could not be reared on any of the fungal isolates nor in the callus tissues of creeping thistle. In contrast to D. weischeri, D. dipsaci was successfully reared on the alfalfa callus tissue. On the callused carrot disks, with no media, an increase of 54 and 244 times the initial density of 80 nematodes was obtained for D. weischeri and D. dipsaci, respectively. Monoxenic rearing was performed using callused carrot disks to provide sufficient D. weischeri inoculum for the microplot study. The effect of D. weischeri on yellow pea varieties Agassiz and Bronco was determined in a microplot trial using initial densities of 0, 100, 200, 400, 800, 1600, and 3200 nematodes/plant. While it had no impact on pea grain yield, D. weischeri slightly reduced plant height, aboveground biomass, and pod length at the population densities of 1600 and 3200 nematodes/plant. The final population densities at harvest were not significantly different from the initial densities indicating the pea varieties were poor hosts to D. weischeri. The results of the present study indicate that D. weischeri is unlikely to be a pest of yellow pea for weather conditions of the Canadian Prairies.

오이 검은별무늬병 방제에 효과적인 유기농업자재 선발

오이 검은별무늬병 방제에 효과적인 유기농업자재 선발

Additional Studies on the Antifungal Activity of a Methanol Extract of Ipomoea Carnea Subsp. Fistulosa and Octadecyl P-Coumarates

Background: Ipomoea carnea subsp. fistulosa is a plant native to South America, but sparsely distributed in India and Bangladesh. Aphrodisiac, purgative, cathartic and sore curing properties have been attributed to the plant. Although there were several papers on the antifungal and antibacterial activities of on the crude extractives of the plant, the first report on the bioassay monitored isolation and characterization of the chief antifungal compounds as a mixture of E and Z isomers of octadecyl p-coumarates was published from this Institute. Material and Methods: The methanol extractive of Ipomoea carnea subsp. fistulosa exhibited antifungal activity against the mycelial growth of Phytophthora nictotiana by poisoned food technique. This is in addition to the reported activity against Colletotrichum gloeosporioides. Results and Discussion: Octadecyl p-coumarates isolated from the plant by column chromatography followed by HPLC exhibited activity against the mycelial growth of Cercospora capsici. This is in addition to the reported activity of octadecyl p-coumarates against the spore germination of Alternaria alternata, Alternaria porri and Cladosporium cucumerinum. Conclusion: Additional studies conducted with the crude extractive of Ipomoea car nea subsp. fistulosa confirmed its antifungal activity against Phytoph thora nicotianae. Identification of octadecyl p-coumarates as antifungal active principles was confirmed by its activity against Cercospora capsici by modified mycelial growth inhibition study.

오이 유묘와 과실을 활용한 검은별무늬병에 대한 저항성 품종 검정 방법

본 연구는 ê²€ì€ë³„ë¬´ëŠ¬ë³‘ê· ì˜ ë°°ì–‘ì  및 병원학 특성을 êµ¬ëª í•˜ê³ , 81개 시판 오이 í’ˆì¢ ì˜ ì €í•­ì„± 여부를 ê²€ì •í•˜ê¸° 위해 수행되었다. ì‹œí—˜ê· ì€ 2015ë „ 3월 말 경기도 평택에 위치한 시설 오이 재배농가에서 채취한 ë³‘ë“ ê³¼ì‹¤ë¡œë¶€í„° ë¶„ë¦¬í•˜ì˜€ê³ PDA상에서 배양하면서 í˜•íƒœì ì¸ 특성에 근거하여 ê²€ì€ë³„ë¬´ëŠ¬ë³‘ê· (C. cucumerinum PT1)으로 ë™ì •ë˜ì—ˆë‹¤. 상처 ìœ ë¬´ì™€ 과실 크기가 검은별무늬병의 발생에 미치는 영향을 ê·œëª í•˜ê¸° 위해 과일 크기를 ìœ ê³¼(10 cm 미만), 중과(10-20 cm), 대과(20 cm 초과)로 êµ¬ë¶„í•˜ê³ ê³¼ì‹¤ 크기별로 상처와 무상처 조건으로 오이 과실표면에 1×105 포자/ml 농도의 ë³‘ì›ê· ì„ ì ‘ì¢ í•˜ì˜€ë‹¤. 작은 과실에서는 표면 상처 여부에 관계없이 심한 수침상의 병반과 ë¹ ë¥¸ ë³‘ì›ê· ìƒìž¥ì„ 보이면서 피해 ì •ë„ê°€ 매우 컸던 반면, 중과와 대과에서는 상처 부위와 무상처 표면 모두에서 경미한 수침상의 병반이 나타났지만 식물체 안쪽 조직으로 병이 ì§„ì „ëœ 것은 상처 낸 과실에서 뿐이었다. 오이 ìœ ë¬˜ì™€ ìœ ê³¼ì— ê²€ì€ë³„ë¬´ëŠ¬ë³‘ê· ì˜ 포자 현탁액을 ì ‘ì¢ í•˜ì—¬ 81개 시판 오이 í’ˆì¢ ì˜ 병 ì €í•­ì„±ì„ 평가한 ê²°ê³¼, 미니오이와 피클오이 í’ˆì¢ êµ°ì€ 대부분 ì €í•­ì„±ì´ì—ˆë‹¤. 특히 ‘처음처럼’ í’ˆì¢ ì€ 아무런 병징이 나타나지 않았으며 나머지 í’ˆì¢ ë“¤ì€ ì €í•­ì„±-ì¤‘ë„ì €í•­ì„±ìœ¼ë¡œ 나타났다. 반면, 다른 í’ˆì¢ êµ°ì˜ 오이 í’ˆì¢ ì€ 대부분 감수성 í’ˆì¢ ìœ¼ë¡œ íŒëª ë˜ì—ˆë‹¤. C. cucumerinum PT1에 대한 오이의 병 ì €í•­ì„±ì€ í’ˆì¢ ê°„ ìœ ì˜í•˜ê²Œ 차이를 보였으며 일부 í’ˆì¢ ì— 있어서 ìœ ë¬˜ ê²€ì •ê³¼ ìœ ê³¼ ê²€ì • 간에 차이를 보였다. 따라서 검은별무늬병에 대한 ì €í•­ì„± í’ˆì¢ ì„ ì„ ë°œí•˜ê¸° 위해서 오이 ìœ ë¬˜ ê²€ì •ê³¼ ìœ ê³¼ ê²€ì •ì„ 병행하여 ì‚¬ìš©í• í•„ìš”ê°€ ìžˆë‹¤ê³ ìƒê°í•œë‹¤. 이상의 결과를 í† ëŒ€ë¡œ ì„ ë°œëœ ì €í•­ì„± í’ˆì¢ ì„ 농가에 ì ìš©í•œë‹¤ë©´ 오이 검은별무늬병 ë°©ì œë¥¼ 위한 ì‹¤ì§ˆì ì¸ 방법이 ë ìˆ˜ 있을 ê²ƒì´ë¼ê³ ìƒê°ëœë‹¤.

Dry Heat Treatment Reduces the Occurrence of Cladosporium cucumerinum, Ascochyta citrullina, and Colletotrichum orbiculare on the Surface and Interior of Cucumber Seeds

Dry heat treatment has been identified as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber (Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight, and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significantly reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.

버섯 폐배지로부터 분리한 방선균 균주 CA-23과 AA-65균주의 키틴 분해능력과 항균력 검정

본 연구의 목적은 버섯폐배지로부터 분리한 방선균의 키틴 분해 능력과 항균활성능력을 검정하고 선발하기 위함이다. 5종류의 버섯폐배지(팽이버섯, 잎새버섯, 느타리버섯, 신령버섯, 양송이버섯) 중 신령버섯 > 양송이버섯 순으로 방선균이 분리되었다. 버섯 폐배지로부터 전체 91개의 키틴분해 방선균을 분리하였다. 분리한 91개의 균주는 키틴분해 능력과 Phytophthora capsici, Rhizoctonia solani, Sclerotinia sclerotiorum, Collectotrichum gloeosporioides, Cladosporium cucumerinum 에 대한 항균력에 따라 크게 3개의 그룹으로 분류하였다. CA-23균주는 강한 키틴 분해능력과 모든 식물병원균에 대해 항균력을 보이는 대표적인 균주로 선발하였고 반면에 AA-65 균주는 키틴 분해능력은 없지만 모든 식물 병원균에 대한 강한 항균력을 보이는 대표적인 균주로 선발하였다. 실내시험에서 CA-23 균주와 AA-65 균주는 오이 역병, 흰가루병, 검은별무늬병을 효과적으로 방제하였다. CA-23 균주는 높은 방제가를 보인 반면 AA-65 균주는 병 방제효과뿐만 아니라 식물생육과 수량을 지속적으로 증가시켰다. 비록 두 균주의 식물병 방제효과 유사하지만 두 균주 사이의 작용기작은 서로 다를 것으로 사료된다. 향후 작용기작과 적용방법에 대한 추가적인 연구가 필요할 것으로 사료된다. The purpose of this study was to estimate the chitinolytic and antifungal activity of Actinomycetes sp.isolated from waste mushroom media. In five kinds of waste mushroom media, Sinyeong mushroom and Yangsongi were the order of the population density of actinomycetes. Totally 91 chitinolytic isolates of Actinomycetes sp. were obtained from waste mushroom media. The isolates were categorized into 3 groups based on chitinolytic activity and antagonisms against Phytophthora capsici, Rhizoctonia solani, Sclerotinia sclerotiorum, Collectotrichum gloeosporioides, and Cladosporium cucumerinum in vitro. CA-23 was selected as a representative isolate of a group showing strong chitinolytic and antagonistic activities to all of the plant pathogens, while AA-65 was selected as a representative isolate showing no chitinolytic activities but strong antagonistic activities to the pathogens. CA-23 and AA-65 were highly effective on control of Phytophthora blight of hot-pepper, powdery mildew and scab of cucumber in a greenhouse tests. Among the isolates tested, CA-23 showed highest control efficacy, while AA-65 not only effectively controlled the diseases but also consistently increased plant growth and yield. Although the isolates are similarly affected on suppression of plant pathogens, the isolates could be differ from each other in modes of action. Further studies on mechanisms and practical applications are being progressed.

Sulfated steroid-amino acid conjugates from the Irish marine sponge Polymastia boletiformis.

Antifungal bioactivity-guided fractionation of the organic extract of the sponge Polymastia boletiformis, collected from the west coast of Ireland, led to the isolation of two new sulfated steroid-amino acid conjugates (1 and 2). Extensive 1D and 2D NMR analyses in combination with quantum mechanical calculations of the electronic circular dichroism (ECD) spectra, optical rotation, and 13C chemical shifts were used to establish the chemical structures of 1 and 2. Both compounds exhibited moderate antifungal activity against Cladosporium cucumerinum, while compound 2 was also active against Candida albicans. Marine natural products containing steroidal and amino acid constituents are extremely rare in nature.