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•Trichoderma spp. were screened for anti-Phytophthora activity.•Trichoderma atroviride/petersenii (KACC 40557) showed the best anti-Phytophthora activity.•Trichoderma metabolite ...treatment caused plant hormonal and transcriptional changes.
Trichoderma species are well-known biological control agents. In this study, metabolites from 128 Trichoderma isolates were extracted from liquid cultures using ethyl acetate and tested for their activities against seven Phytophthora isolates. Following preliminary analysis, eight Trichoderma isolates were selected for further tests. Among them, the metabolites from Trichoderma atroviride/petersenii (KACC, Korea Agricultural Culture Collection, 40557) and Trichoderma virens (KACC 40929) showed the strongest inhibitory activities against Phytophthora isolates. Treatment with KACC 40557 extract inhibited Phytophthora growth, induced defense-related genes, and caused plant hormonal changes during Phytophthora infection in the detached leaves of pepper and tomato plants. Our results showed the potential for use of Trichoderma metabolites as biological control agents against Phytophthora pathogens.
The main purpose of this study was to compare the prediction accuracies of various seismic vulnerability assessment and mapping methods. We applied the frequency ratio (FR), decision tree (DT), and ...random forest (RF) methods to seismic data for Gyeongju, South Korea. A magnitude 5.8 earthquake occurred in Gyeongju on 12 September 2016. Buildings damaged during the earthquake were used as dependent variables, and 18 sub-indicators related to seismic vulnerability were used as independent variables. Seismic data were used to construct a model for each method, and the models’ results and prediction accuracies were validated using receiver operating characteristic (ROC) curves. The success rates of the FR, DT, and RF models were 0.661, 0.899, and 1.000, and their prediction rates were 0.655, 0.851, and 0.949, respectively. The importance of each indicator was determined, and the peak ground acceleration (PGA) and distance to epicenter were found to have the greatest impact on seismic vulnerability in the DT and RF models. The constructed models were applied to all buildings in Gyeongju to derive prediction values, which were then normalized to between 0 and 1, and then divided into five classes at equal intervals to create seismic vulnerability maps. An analysis of the class distribution of building damage in each of the 23 administrative districts showed that district 15 (Wolseong) was the most vulnerable area and districts 2 (Gangdong), 18 (Yangbuk), and 23 (Yangnam) were the safest areas.
Recently, the occurrence of "Cenangium-dieback" has been frequent and devastating. Cenangium-dieback is caused by an endophytic fungus Cenangium ferruginosum in stressed pine trees. Progression of ...the disease in terms of molecular interaction between host and pathogen is not well studied and there is a need to develop preventive strategies. Thus, we simulated disease conditions and studied the associated transcriptomics, metabolomics, and hormonal changes. Pinus koraiensis seedlings inoculated with C. ferruginosum were analyzed both under drought and well-watered conditions. Transcriptomic analysis suggested decreased expression of defense-related genes in C. ferruginosum-infected seedlings experiencing water-deficit. Further, metabolomic analysis indicated a decrease in the key antimicrobial terpenoids, flavonoids, and phenolic acids. Hormonal analysis revealed a drought-induced accumulation of abscisic acid and a corresponding decline in the defense-associated jasmonic acid levels. Pathogen-associated changes were also studied by treating C. ferruginosum with metabolic extracts from pine seedlings (with and without drought) and polyethylene glycol to simulate the effects of direct drought. From RNA sequencing and metabolomic analysis it was determined that drought did not directly induce pathogenicity of C. ferruginosum. Collectively, we propose that drought weakens pine immunity, which facilitates increased C. ferruginosum growth and results in conversion of the endophyte into the phytopathogen causing dieback.
Schw. is a microcyclic rust fungus, first found on
Lour in North Carolina, the United States. This rust fungus is native to the continental United States, Hawaii, Mexico, and the West Indies (Arthur ...1934). It has become notoriously invasive and is now distributed in the Europe (Bulgaria, France, Hungary, Italy, Romania, Spain, and the former Yugoslavia), India, Indonesia, Australia, and South Africa (Parmelee 1969; Alcorn 1976; Wahyuno 2012). In East Asia, the fungus has been reported in Japan (Hiratsuka et al. 1992) and China (Zhao et al. 2014) but not in Korea. It has been reported mainly on the invasive weeds
and
species. In addition, it rarely occurs on sunflowers (
spp.) in Australia (Alcorn 1976), South Africa (Pretorius et al. 2000), and North America (Gulya and Charlet 2002). In Korea, rust disease symptoms caused by a
fungus were first found on
L. at the roadside of Okcheon-gun, Chungcheongbuk-do (36 27'95.428"N 127 66'26.378"E) in October 2021 and were repeatedly observed in the same site in 2022. The similar symptom was additionally found on
in Yesan-gun, Oct. 2022. The symptoms were brown spots on round chlorotic haloes on the adaxial leaf surface and dark brown pustules on the abaxial leaf surface. Telia were brown to dark brown, round, mostly grouped, 0.28-0.61 mm in diameter, and mainly formed on the abaxial leaf surface but sometimes on the adaxial leaf surface. Teliospores were two-celled, pedicellate, and measured 37.6-110 × 12.4-21.5 μm in size; the wall was yellowish or almost colorless, smooth, 1.2-2.6 μm thick at the sides, and up to 7.4 μm thick at the apex. The morphological characteristics of the teliospores were identical to those of
described by Arthur (1934) and Parmelee (1969). Based on phylogenetic analyses (e-Xtra 2) of the internal transcribed spacer (ITS) and partial large subunit (LSU) rDNA extracted from the teliospores, they were identified as
. BLAST analysis showed that the sequences had high homologies (over 99.82%) with the reference strains of
(EF635903 and KX999896). The representative specimens were preserved at the Animal and Plant Quarantine Agency Herbarium (PQK211005 for Okcheon-gun isolate and PQK220913 for Yesan-gun) and the sequences were deposited in GenBank (OR958716 and OR958692). A pathogenicity test was performed by dropping a suspension of germinating teliospores and basidiospores onto the adaxial leaf surfaces of apparently healthy
plants in Oct. 2022, using the isolate PQK220913 (OR958692). The three inoculated plants were placed together with three controls treated with only distilled water, in the dark at saturated humidity for 24 hours in an isolated greenhouse. After two weeks, typical rust symptoms were observed in the three infected plants, whereas no symptoms appeared in the control plants (e-Xtra 1). The causal fungus was identified as
based on host relationships, successful experimental inoculation, morphological characteristics, and sequence similarity of partial DNA fragments. To our knowledge, this is the first report of
on
in Korea.
was additionally confirmed on
in Gumi-si, Boeun-gun, Seongju-gun, Naju-si, and Gunsan-si in 2023, indicating its wide distribution in Korea. It is expected that
could be a candidate as a biological agent for controlling the invasive weed,
.
Mill is a deciduous broad-leaved shrub belonging to the Solanaceae family and, is widely distributed throughout Korea. This plant is native to, or cultivated for various oriental medicinal purposes ...in, multiple regions of Asia, including Korea, China, and Japan (Lee 1982; Kim et al. 1994). Eleven
species have been reported to infect
species (Otálora et al. 2018). In May and October 2022, symptoms of rust disease caused by
sp. were observed on almost all the leaves of about 60 sprawling stems of
plants on the seashore of Jeju island, Korea (33°14'15.0835″N, 126°30'53.40E). Brownish red (uredinium) or blackish brown (telium) pustules were observed on upper and lower surfaces of infected leaves. These symptoms were observed on about 40
plants, barely growing between rocks on the seashore of Ulsan Metropolitan City, and on the about 20
plants on a small home garden of Jindo-gun, Korea, in June and October 2023, respectively. Uredinia were amphigenous, individually scattered, but sometimes formed groups of two or three on leaves and sepals, ferruginous, pulverulent, and surrounded by a ruptured epidermis, often developing into blackish telia. Urediniospores were either ellipsoid or ovoid, approximately 29.3-34.9 × 17-24.3 μm, with yellowish walls, 1-2 μm thick. The germ pores were bizonate, and each band contained four pores covered by low papillae. Blackish-brown telia were observed on both leaf surfaces. Teliospores were broadly ellipsoidal, and rounded at the apex and towards the base. They were measured approximately 37.1-53.4 × 25-34.5 μm. The walls were light chestnut-brown and 2-3.7 μm thick, apically up to 5-9 μm thick. The swollen pedicel was persistent, basal, hyaline, smooth, and similar in length to the spores (Fig. 1). These morphological characteristics were similar to those of
, as described by Otálora et al. (2018). The representative specimens were preserved at the Animal and Plant Quarantine Agency Herbarium (PQK220531, -230605, and -231026). The fungal internal transcribed spacer (ITS2) and cytochrome oxidase subunit 3(CO3) regions were amplified from the total DNA of the isolates, using the primer pairs ITS5, ITS4, CO3F1, and CO3R1 for phylogenetic analysis (White et al. 1990; Vialle et al. 2009). PCR products were sequenced (Celemics, Seoul, Korea), and deposited in GenBank (Accession numbers are shown in Fig. 2.). The combined ITS2 and CO3 sequences were grouped with those of other isolates of
in the phylogenetic tree (Fig. 2). In November 2022, three pathogenicity tests were conducted using a urediniospore suspension made with the PQK220531 isolate in sterile distilled water. The suspension was smeared onto the upper surface of healthy
leaves. The three inoculated plants were kept in the dark at saturated moisture levels for 24 hours and placed in an isolated glasshouse together with the three control plants. After two weeks, uredinia of
were observed on the leaves of the inoculated plants, but not on the control plants. Although no spermogonial or aecial stage has been observed in Korea, our study has proven that
is the causal fungus of rust disease in
. This result is also the first discovery of the New-World
in Asia, showing this fungus is not limitedly distributed in America and suggesting further surveys be done on its exact geographical distribution.
(Malvaceae), known as common mallow, is native to Europe, western Asia, and northern Africa. It was intentionally introduced to Korea as an ornamental plant in the early 20th century, and has become ...partly naturalized in several areas including the woods (Jung et al. 2017). Among nine microcylic
species attacking the Malvaceae plants, three species of
, and
have been reported on
(Classen et al. 2000, Colenso 1885, McKenzie 1998 and Melo et al. 2012). Only
has been found on
and
, and not
in Korea (Lee et al. 2022; Ryu et al. 2022). In August 2022, rust disease symptoms of a
fungus were observed on some overgrown seedlings of
, which were neglected in containers after sales at a wholesale nursery (36°50'19.8″N, 128°55'28.7″E) in Bonghwa, Korea. Typical rust spots were observed around 60% (on 111 seedlings of the 186 seedlings of
). The brown spots were produced on round chlorotic haloes on the adaxial leaf surface, and brown to dark brown pustules on the abaxial. Subepidermal spermogonia on the adaxial, were obovoid, and 112.1-160.0 × 88.7-149.3 μm in size. Telia were golden-brown to dark brown, round, mostly grouped, and 0.30-0.72 mm in diameter, and mainly hypophyllus. Fusoid teliospores were two-celled, rarely one- or three-celled, 36.2-92.3 × 10.6-19.3 μm in size, with many anomalies appearing notched at apex; wall was yellowish or almost colorless, smooth, 1.0-2.6 μm thick at the sides, and up to 6.8 μm thick at the apex; pedicel was hyaline, thick wall, persistent, and (39.3-)60.4-154.6(-189.9) μm long. Based on these morphological features together with the results of the phylogenetic analyses (e-Xtra 2) using internal transcribed spacer (ITS) and partial large subunit (LSU) sequences according to the method described by Ryu et al. (2022), the fungus was identified as an autoecious
, recently reported on
and
in Korea (Lee et al. 2022; Ryu et al. 2022). A representative sample was deposited in the Animal and Plant Quarantine Agency Herbarium (PQK220818). Pathogenicity tests were done using three host plants:
and
. Three to four leaf discs with basidiospore-bearing telia were placed on the upper surfaces of healthy young leaves of the seedlings. Three replicates of each host plant set including an untreated control were tested. The plants were kept in an isolated glass house. At ten to twelve days after inoculation, typical telial spots of
were recovered, but not in the control plants, showing all three tested species were highly susceptible (e-Xtra 1). The ITS and LSU sequences obtained from the genomic DNAs of each newly recovered rust spot were consistent with that of the inoculum (accession no. OQ542745). The previous
isolate (OP369290 by Ryu et al. 2022) also showed the pathogenesis on
and
by the same tests, mentioned above (e-Xtra 1). To date, only one collection of
on
has been reported in Louisiana, the United States (Aime and Abbasi 2018). The results of this study show that
is firstly confirmed as the causal rust fungus of
and the same causal agent of
and
rust disease, recently reported in Korea.
, in the family Malvaceae, is a biennial plant native to China and is grown typically for gardening in Korea (Lee 2003). Seven microcyclic
species have been reported on
(Demers et al. 2015; Aime and ...Abbasi 2018). In early May 2022, characteristic symptoms of rust were observed on four of ten seedlings of
purchased at a wholesale nursery (36°50'19.8″N, 128°55'28.7″E) in Bonghwa, Korea. Rust spots were present on almost 90% of the 1,000 seedlings of
in that nursery during our survey in late May. Through a distribution survey from June to July 2022, similar symptomatic leaves were additionally collected from the leaves of
grown in gardens at five sites in Gimcheon (two sites), Gumi (one), Seongju (one), and Busan (one). Spots were yellow-orange the center surrounded by chlorotic haloes on the adaxial leaf surface, and reddish-brown or dark brown pustules on the abaxial leaf surface. Over time, the spots enlarged and coalesced, causing the decay of large sections of the leaves, and heavily infected leaves fell early. Spermogonia, produced at the center of the chlorotic spot on the adaxial leaf surface, were subepidermal, obovoid, and 113.2-164.5 × 97.6-153.3 μm in size. Telia were reddish-brown to dark brown, round, mostly grouped, 0.28-0.61 mm in diameter, and mainly formed on the abaxial leaf surface but sometimes on the adaxial leaf surface also. Teliospores were two-celled, but rarely one- or three-celled, and were fusoid and 37. 6-110 × 12.4-21.5 μm in size; the wall was yellowish or almost colorless, smooth, 1.2-2.6 μm thick at the sides, and up to 7.4 μm thick at the apex. The morphological characteristics were similar to those of P. modiolae, although the teliospores in our study were longer than those observed by Aime and Abbasi (2018). For phylogenetic analysis, genomic DNA was extracted from the teliospores of each regional specimen. Partial 18S, internal transcribed spacer (ITS), and partial 28S sequences were amplified using primers NS1, ITS4, ITS5, and LR11. The PCR products were sequenced (Celemics, Seoul, Korea) and deposited in GenBank. The ITS-partial large subunit (LSU) sequence and 28S sequences had 100% homology with other
sequences deposited in GenBank (accession numbers are shown in Fig. 2). In the phylogenetic trees of the ITS and LSU sequences, the isolates collected in this study were grouped with the reference sequences of
, including the Korean isolate (ON631218) recently reported on
by Lee et al. (2022). For the pathogenicity test, the teliospores with germinating basidiospores were suspended in sterile distilled water and smeared on the upper surface of asymptomatic
leaves in August. The inoculated plants were sprayed with distilled water and kept in the dark with saturated moisture for 24 h in an isolated glass house of the Animal & Plant Quarantine Agent. After 2 weeks, typical rust spots and telia of
were observed on the leaves of the inoculated plants, but not in the control plants, which were only sprayed with distilled, sterilized water and otherwise treated similarly to the inoculated plants. The results of this study show that the casual fungus is
, which has been commonly found in
in Korea. To the best of our knowledge, this is the first report of
in
in Korea.
In this study, we classified land cover using SegNet, a deep-learning model, and we assessed its classification accuracy in comparison with the support-vector-machine (SVM) and random-forest (RF) ...machine-learning models. The land-cover classification was based on aerial orthoimagery with a spatial resolution of 1 m for the input dataset, and Level-3 land-use and land-cover (LULC) maps with a spatial resolution of 1 m as the reference dataset. The study areas were the Namhan and Bukhan River Basins, where significant urbanization occurred between 2010 and 2012. The hyperparameters were selected by comparing the validation accuracy of the models based on the parameter changes, and they were then used to classify four LU types (urban, crops, forests, and water). The results indicated that SegNet had the highest accuracy (91.54%), followed by the RF (52.96%) and SVM (50.27%) algorithms. Both machine-learning models showed lower accuracy than SegNet in classifying all land-cover types, except forests, with an overall-accuracy (OA) improvement of approximately 40% for SegNet. Next, we applied SegNet to detect land-cover changes according to aerial orthoimagery of Namyangju city, obtained in 2010 and 2012; the resulting OA values were 86.42% and 78.09%, respectively. The reference dataset showed that urbanization increased significantly between 2010 and 2012, whereas the area of land used for forests and agriculture decreased. Similar changes in the land-cover types in the reference dataset suggest that urbanization is in progress. Together, these results indicate that aerial orthoimagery and the SegNet model can be used to efficiently detect land-cover changes, such as urbanization, and can be applied for LULC monitoring to promote sustainable land management.
Two placentas in singleton pregnancy with fused umbilical cord which has its own placental insertion site forming 3-vessel cord at fetal end is an extremely rare case. This present case describes two ...placentas with fused umbilical cord with an episode of vanishing twin syndrome and there seems to be a strong relationship between these two events. A 37-year-old woman, gravid 0,para 0, visited emergency room with an episode of vaginal bleeding without pelvic cramps at 8 weeks and 5 days of gestation and repeated ultrasonic exams revealed reabsorption of vanishing twin and two separate placentas on anterior and posterior body of uterus. At 40 weeks and 4 days, the patient delivered a viable female infant weighing 3,900 g via Cesarean section and postpartum examination of the placentas and membranes confi rmed two placentas with fused umbilical cord. Two placentas were almost equal in size and there were 2 cord insertions, 1 into each placenta. The cord at each of the placental disc had marginal insertion site and main placental disc cord had 2 arteries with one vein (3 vessel-cord) whereas side placental disc cord had one artery with one vein (2vessel-cord). Several hypothesis for this two placentas with fused umbilical cord in singleton pregnancy, were proposed including placenta abnormalities after in vitro fertilization-embryo transfer procedure, succenturiate lobes and fetus in fetus, however, further evaluation is need. KCI Citation Count: 0
Multiplicative and additive theoretical models have been proposed to explain how job demands and job resources (e.g., job control, social support) relate to strain. However, there has been mixed ...support for the multiplicative model, and there are questions about the generalizability of both models to strains varying in severity and type, and to different types of demands. Thus, we conducted a meta-analysis of regression coefficients testing the multiplicative and additive models from 77 unique samples and over 141,505 participants, using raw data or correlation matrices supplied by study authors. Overall, we found weak support for the multiplicative model and some support for the additive model. We found that job demands and job control/social support were all weakly to moderately related to employee strain. However, neither the job demands-control nor job demands-social support interactions were meaningfully related to strain in almost all cases. The components of the additive model were more strongly related to primary and tertiary strain indicators than secondary indicators and were more strongly related to psychological strain than to physical or behavioral strain. Both the additive and multiplicative models were more strongly related to strain when demands are conceptualized as hindrances rather than challenges. Meta-analyses of the simple slopes showed that job control and social support generally buffered the effects of job demands on strain, but the effects were weak and not significantly different across different levels of control and support. Theoretical and practical implications, as well as future research directions, are discussed.
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