National Academy of Agricultural Science

This study is based on academic literature rather than empirical analysis due to the absence of empirical data related to Bitcoin demand (currency vs. assets). This paper investigates Bitcoin's function as a financial asset (speculation, distribution, hedging, and safe assets) in the asset portfolio in terms of four aspects. First, some studies that show that Bitcoin cannot be recognized as a currency due to its lack of basic function as a currency, but many studies suggest the possibility of Bitcoin developing as a currency in the future. In order to monetize Bitcoin, tasks such as spreading adoption as a means of payment and settlement, establishing a legal system, and agreements between countries are placed. On the other hand, from an asset portfolio perspective, studies that refuse to recognize Bitcoin as a currency classify Bitcoin as a highly volatile profit-seeking speculative asset. Second, in terms of asset portfolios, Bitcoin is recognized as having a distributed function in correlation with other assets. Third, economic uncertainty indices recognize that Bitcoin has a hedge function against rapidly changing market volatility. Finally, Bitcoin is going to evolve like gold, although it is hitting the market, it has been found that it lacks functions as a safe asset such as gold. According to the literature review, Bitcoin's characteristics as an asset are not mutually exclusive with the financial asset characteristics of currency, raw materials, and stocks, and these characteristics mean that it can perform multiple financial asset functions of variance and hedge within the asset portfolio.

Tractor fuel consumption has typically been predicted using indoor test results under specific conditions. This study analyzes the factors affecting fuel consumption during rotary tillage in actual fields and develops a prediction model. The test field was divided into sections using a grid method, and rotary tillage operations were performed to measure various parameters, including soil strength, tractor’s transmission and PTO gear stages, tillage pitch, travel speed, engine and PTO shaft torque and speed, and fuel consumption. Pearson correlation identified variables affecting specific fuel consumption, and regression analysis was used to develop a prediction model. The model’s accuracy was analyzed using the coefficient of determination (R2) and root mean square error (RMSE), and it was compared with the ASABE’s fuel consumption prediction model. The test results showed that higher transmission and PTO gear stages, and tillage pitch decreased specific fuel consumption, while soil strength had no significant effect. Thus, operating at higher gear and PTO stages within suitable conditions enhances energy efficiency in rotary tillage. Statistical analysis showed that specific fuel consumption significantly correlated with tractor travel speed, PTO shaft power, and PTO shaft speed. The prediction model, including these variables, had the highest accuracy with R2 of 0.91 and RMSE of 0.011 L/kW·h. The developed prediction model showed significantly improved accuracy compared to the ASABE model, indicating that it can predict specific fuel consumption based on key operational variables in actual rotary tillage operations.

Anthracnose, a destructive fungal disease, poses a significant threat to chili pepper (Capsicum annuum L.) production worldwide (de Silva et al. 2019). In South Korea, anthracnose outbreaks have traditionally been attributed to several Colletotrichum species such as C. gloeosporioides and C. acutatum. About 10% of the yield (chili production) is lost annually in South Korea due to chili anthracnose (Oo et al. 2020). During field surveys conducted in August 2017, symptomatic lesions resembling anthracnose were observed on chili pepper in two farmer's fields (Gochang and Cheongyang) in South Korea. Affected fruits exhibited characteristic symptoms, including circular sunken lesions with dark margins and abundant orange spore masses on the surface. About 20% of chili pepper fruit were affected in each field with an area of about 0.2 ha. Five putative Colletotrichum spp. isolates were obtained from six affected fruits (three from each field) following the procedure described by Cai et el. (2009). Three isolates (C01049, C01111, and C01115), representing each location, were selected to identify at the species level. Colonies on potato dextrose agar (incubated at 25°C in the dark for 7 days) were cottony with entire margins, white aerial mycelium and dark gray in the center. Conidia were hyaline, aseptate, cylindrical with bothnds round, and 17.8 - 30.5 × 6.0 -10.0 µm (mean 23.8 ×7.9 μm, n = 30). Appressoria were dark brown, irregular but mostly ovoid with smooth walls. These morphological features align with those of Colletotrichum spp. within the Colletotrichum gigasporum species (Liu et al. 2014). The identity of the pathogen was further confirmed through multi-locus phylogenetic analysis. The target genes including ITS, ACT, CHS-1, GAPDH, TUB2, and GS were amplified and sequenced using the primer sets ITS1/ITS4, ACT 512F/ ACT-783R, CHS-79F/ CHS-345R, GDF/GDR, T1/Bt2b, and GSF1/GSR1, respectively (Weir et al. 2012; Liu et al. 2014). The resulting sequences were deposited in GenBank (accession no: ITS: MT605261, MT605262, LC823714; ACT: MT612991, MT612992, LC823718; CHS-1: MT612993, MT612994, LC823717; GAPDH: LC811375, LC811376, LC823716; TUB2: MT612997, MT612998, LC823715; GS: LC811377, LC811378, LC823719). The constructed Bayesian and maximum likelihood tree based on combined sequences of ITS, ACT, CHS-1, GAPDH, TUB2, and GS confirmed the identification of the isolates (C01049, C01111, C01115) as C. gigasporum. Pathogenicity tests were conducted by inoculating healthy chili fruit with 70 µL of a conidial suspension (1×106 conidia /mL) of pure cultures of the isolates. The conidial suspension was applied on 10 wounded or 10 non-wounded fruit. The same number of fruit were treated with sterile distilled water as controls. Within 5 days of inoculation, symptoms consistent with anthracnose developed on the inoculated wounded fruit, whereas non-wounded and control fruit remained asymptomatic. This experiment was repeated twice. Colletotrichum gigasporum was re-isolated from diseased tissue of inoculated fruit. Colletotrichum gigasporum has been identified as the cause of anthracnose on Dalbergia odorifera, Carica papaya in China, and Brassica oleracea in India (Wan et al., 2018; Saini et al. 2022; He et al. 2023). To the best of our knowledge, this report marks the first documented instance of C. gigasporum causing anthracnose of chili pepper in South Korea. These results indicate that various species of Colletotrichum can be the fungi causing chili pepper anthracnose. The findings of this study emphasize the need for effective disease management strategies to mitigate impact of C. gigasporum on chili pepper cultivation in the region.

Key messageBulked segregant RNA seq of pools of pepper accessions that are susceptible or resistant to Broad bean wilt virus 2 identifies a gene that might confer resistance to this devastating pathogen.The single-stranded positive-sense RNA virus Broad bean wilt virus 2 (BBWV2) causes substantial damage to pepper (Capsicum annuum) cultivation. Here, we describe mapping the BBWV2 resistance locus bwvr using a F7:8 recombinant inbred line (RIL) population constructed by crossing the BBWV2-resistant pepper accession ‘SNU-C’ with the susceptible pepper accession ‘ECW30R.’ All F1 plants infected with the BBWV2 strain PAP1 were susceptible to the virus, and the RIL population showed a 1:1 ratio of resistance to susceptibility, indicating that this trait is controlled by a single recessive gene. To map bwvr, we performed bulked segregant RNA-seq (BSR-seq). We sequenced pools of resistant and susceptible lines from the RILs and aligned the reads to the high-quality ‘Dempsey’ reference genome to identify variants between the pools. This analysis identified 519,887 variants and selected the region from 245.9–250.8 Mb of the Dempsey reference genome as the quantitative trait locus region for bwvr. To finely map bwvr, we used newly designed high-resolution melting (HRM) and Kompetitive allele specific PCR (KASP) markers based on variants obtained from the BSR-seq reads and the PepperSNP16K array. Comparative analysis identified 11 SNU-C-specific SNPs within the bwvr locus. Using markers derived from these variants, we mapped the candidate bwvr locus to the region from 246.833–246.949 kb. SNU-C-specific variants clustered near DEM.v1.00035533 within the bwvr locus. DEM.v1.00035533 encodes the nitrate transporter NPF1.2 and contains a SNP within its 5′ untranslated region. The bwvr locus, which contains four genes including DEM.v1.00035533, could represent a valuable resource for global pepper breeding programs.

Juvenile hormones (JHs) play a central role in insect development, reproduction, and various physiological functions. Curcuminoids generally exhibit a wide range of biological activities, such as antioxidant, anti-inflammatory, antibacterial, and insecticidal, and they exhibit insect growth inhibitory effects. However, research on insecticidal properties of curcuminoids has been limited. Moreover, to the best of our knowledge, studies on JHs of insects and curcuminoids are lacking. Therefore, this study aimed to identify the substances that act as JH disruptors (JHDs) from edible plants. Demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), two curcuminoids from the turmeric plant Curcuma longa L. inhibited the formation of a methoprene-tolerant (Met)-Taiman (Tai) heterodimer complex in Drosophila melanogaster, as shown through in vitro yeast two-hybrid assays. An artificial diet containing 1% (w/v) DMC or BDMC significantly reduced the number of D. melanogaster larvae in a concentration-dependent manner; larval development was disrupted, preventing the progression of larvae to pupal stages, resulting in an absence of adults. Building on the results obtained in this study on curcuminoids, researchers can use our study as a reference to develop eco-friendly pesticides.

In this study, we confirmed the binding of M13KO7 to Potato virus Y (PVY) using enzyme-linked immunosorbent assay. M13KO7 is a "bald" bacteriophage in which no recombinant antibody is displayed. M13KO7 is easy to propagate by using Escherichia coli, making this method more reasonable in economic perspective. Based on this study, we suggest that M13KO7 detection system has applicability as a novel biological tool for the detection of PVY.

To investigate the incidence status of viruses in major cultivated areas of watermelon and melon in Chungbuk Province, samples were collected from 2020 to 2021 in vinyl greenhouse of Jincheon and Eumseong and examined for virus infection using reverse transcription polymerase chain reaction. Of the six viruses on watermelon that was analyzed in this study, watermelons were infected with cucumber mosaic virus (CMV), watermelon mosaic virus (WMV), cucumber green mottle mosaic virus (CGMMV), and cucurbit aphid-borne yellows virus (CABYV). The incidence rate of CMV was 20.9–35.0%, WMV 0.4–15.8%, CGMMV 1.6–38.5%, and CABYV was 3.5–3.7% from 2020 to 2021. But strangely, there were no incidence of zucchini yellow mosaic virus and cucurbit chlorotic yellows virus (CCYV) during investigation. From this result, we knew the major virus was CGMMV on watermelon in Chungbuk Province. Molecular diagnosis assays of the two melon viruses, showed that melons were infected with CABYV and CCYV from 2020 to 2021. The incidence rate of CABYV was 53.9–92.2% and CCYV was 2.7–20.8%. The incidence of CABYV was high in melon cultivation of Jincheon and Eumseong, Chungbuk. Afterwards, it is necessary to establish a control management strategy for reduce the incidence of CABYV. Furthermore, we must pay attention that of CCYV even if the incidence was low.

Rice is a source of food for the majority of the global population. Currently, the rice yield is declining owing to extreme climate change. Farmers use nitrogen fertilizers to increase the yield; however, excessive nitrogen fertilizer application has a negative impact on plants and the environment. Nitrogen fertilizer is necessary for the growth of rice, but it is an important cause of environ-mental pollution. Carbon monoxide (CO) emitted from rice fields due to nitrogen fertilizer reacts with greenhouse gases such as carbon dioxide or methane, affecting global warming. Although CO does not directly affect global warming, it is a gas that needs attention because it reacts with various other gases. In this study, a chamber was designed and manufactured to collect the CO emitted from the paddy field after nitrogen fertilizer application in 2021 and 2022. In paddy fields, nitrogen fertilizer treatment affected the pH, EC, and soil temperature, and affected various agricultural traits. Various agricultural characteristics and the number of spikes, number of tillers, and chlorophyll content increased with nitrogen fertilizer application, whereas the amylose content decreased. Adequate nitrogen fertilizer should be applied to increase the rice yield; however, excessive nitrogen fertilizer application has a serious negative effect on grain quality and can accelerate global warming by releasing CO from paddy fields. The appropriate application of nitrogen fertilizer can have a positive effect on farmers by increasing yield. However, caution should be exercised in the application of excessive nitrogen fertilizers, as excessive nitrogen fertilizers increase the emission of CO, which affects greenhouse gases.