• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.522-528
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• 2018

Saemimyeon, a Tongil type, medium-late maturing rice variety, is especially used for preparing rice noodles. Its high amylose content was developed to fit market demands and to be affordable for rice processing industries. One of the high yielding lines, Milyang181 (Hanareum), was used in the final three-way cross of $IR50^*2$/YR18241-B-B-115-1-1 for yield improvement and cultivation stabilization, including disease resistance. YR24235-10-1-3, a high yielding and compact plant type, was selected and named Milyang278 after yield test at NICS (RDA, Miryang) in 2010. It was subjected to regional yield test at six sites in the middle and southern plain areas of South Korea. Saemimyeon heading occurs on August 12 and is a mid-late maturing cultivar, with resistance to leaf blast, rice stripe virus, and bacterial blight (K1-K3a), but it is susceptible to major diseases and insect pest infestation. Saemimyeon showed a high amylose content of 26.7%, with a relatively low KOH digestion value of 3.5, which are key factors in rice noodles and pasta processing. In the local adaptability tests, the yield of Saemimyeon was 7.08 MT/ha-an increase of approximately 106% compared to that of Dasan. Thus, Saemimyeon is suitable for cultivation in the southern and middle plain areas of South Korea.

• Korean Journal of Medicinal Crop Science
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• v.23 no.5
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• pp.385-394
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• 2015

Background : Dibenzocyclooctadiene lignans are secondary metabolites present abundantly in the fruits belonging to the genus Schisandra. According to previous studies, Schisandra lignans exhibit anti-inflammatory, anti-cancer and anti-diabetic properties, as well as an inhibitory effect on platelet aggregation. Therefore, establishing the Korean "Omija" (Schisandra chinensis) as a lignan-rich source, in addition to identifying and quantifying the lignans, is extremely valuable. Methods and Results : Dibenzocyclooctadiene lignans were analyzed with liquid chromatography using diode array detection/mass spectrometry, from methanol extracts subsequently identified by a constructed chemical library of 50 lignans. A total of 27 components of lignan including gomisin S were identified, of which schisandrin, gomisin A, gomisin N, deoxyschisandrin, ${\gamma}$-schisandrin, and schisandrin C were identified as the major components in the Korean Omija, Schisandra chinensis. These compounds were divided into two groups, S-biphenyl and R-biphenyl based on the configurations of the stereoisomers structures with contents of 661.7 and 1350.1mg per 100 g dry weight, respectively. The total lignan content averaged 2011.4mg per 100 g dry weight, of which schisandrin and gomisin N comprised the majority (771.8 and 420.5mg per 100 g dry weight respectively). Conclusions : Lignans which are present in high quantities in the ripe fruit of Schisandra chinensis are important functional compounds that play a major role in the prevention and treatment of human diseases.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.199-202
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• 2007

This study was carried out to provide pest control information for the cultivation of Eleutherococcus senticosus Max. As a result of investigation of the diseases and insect pests, three pathogens and three insect pests were identified from the field sample, respectively. The identified insects pests were aphids, stinkbugs and Bothrogonia japonica. Occurrenre peaks of aphids were occurred on June and August, and generally young leaves and flower buds were injured mainly. The identified diseases were black ring spot caused by Phoma sp., gray mold caused by Botrytis cinerea and leaf blights caused by Rhizoctonia solani. The black ring spot was the most severe disease and was investigated from the beginning of June, and the incidence of the disease was 30% higher than that on September. As a result of growth test under different temperature conditions on PDA, these pathogens showed the best mycelial growth rate between 25 $^{\circ}$C and 30 $^{\circ}$C, and these results indicate that these diseases occur on hat summer season.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.407-415
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• 2014

Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.212-226
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• 2002

North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.413-421
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• 2011

The main objective of this study was to develop the multi-resistance lines to insects(brown planthopper; BPH, rice green leafhopper; GRH) and disease(blast; BL, bacterial blight; BB and rice stripe virus disease;RSV) with good grain quality and plant type by combining conventional breeding and marker assisted selection(MAS) and to eliminate the linkage drag effects between Bph1 gene and culm length, we conducted MAS of Bph1 gene in advanced backcross and double cross progenies. 'Nampyeong', 'Junam' and 'Milyang220' were used as the parent in this study. 'Milyang220' was used as the donor of brown planthopper resistance gene Bph1 with tall culm length. Two backcross progenies were developed using two recipients 'Nampyeong' carrying GRH resistance gene Grh3(t) with good grain appearance and 'Junam' harboring bacterial blight resistance gene Xa3 with short culm length. Two $BC_1$ generations were resulted from the backcrossing of the $F_1$ plants with recurrent parents 'Nampyeong' and 'Junam'. The second rounds of backcrossing($BC_2$) were derived from the cross of selected resistant $BC_1F_1$ plants based on heterozygous genotype of RM28493 linked to Bph1 gene. The double crossed population was constructed from the cross of between each heterozygous $BC_2F_1$ plants at RM28493 locus of '$Nampyeong^*3$ / Milyang220' and '$Junam^*3$ / Milyang220'., The homozygous alleles in Bph1 gene were selected using co-dominant DNA marker RM28493 in double crossed population. Eighty-five lines with multi-resistance to BL, BB, RSV, GRH and BPH were selected by bio-assay and MAS in generation of double crossing. The culm length, head rice ratio and yield of the selected multi resistance lines was ranged from 71 to 88 cm, from 51 to 93%, from 449 to 629 kg/10a. respectively. We can select a promising multi resistance line similar with 'Nampyeong' of major agronomic traits such as culm legnth, head rice ratio and yield. It was designated as Milyang265. Finally this study was developed the multi resistant varieties against to insects and diseases with the good grain quality 'Milyang265' by the advanced backcross and double cross combining MAS and it can be used as genetic resources of multi-resistance to insect and diseases in rice breeding programs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.339-349
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• 2021

In recent years, the occurrence of bacterial diseases of soybean has been increasing due to the continuous rise in spring temperature and the humid weather as a result of rain concentrated at the middle and late stages of crop growth. The resulting severe economic damage is also a concern. Unfortunately, there are no precise data on the occurrence and damage to lay the foundation for bacterial disease control in soybean in the Chungbuk Province. Therefore, the present study investigated the occurrence of major bacterial diseases, namely bacterial pustules, bacterial blight, and wildfire, in different soybean varieties in 410 fields in the Chungbuk Province in 2017. The incidence rate of bacterial pustules in the affected fields was 76.6%, and the incidence rate of infected plants was 29.3%. The incidence rate of bacterial blight in the affected fields was 13.9%, and the incidence rate of infected plants was 4.6%. The incidence rate of wildfire in the affected fields was 23.2%, and the incidence rate of infected plants was 10.1%. The overall incidence rate of bacterial diseases in the soybean fields where the diseases originated was 37.9% for bacterial pustules, 21.0% for bacterial blight, and 25.0% for wildfire, indicating that the disease incidence rate in fields where the disease originated was generally high. Among different varieties, the incidence rate of bacterial pustules was the highest in sprout soybean (88.9%), followed by Seoritae (84.0%) and Daewon (81.2%). The incidence rate of bacterial blight was the highest in the Daewon (19.6%), followed by Seoritae (15.2%) and sprout soybean (12.5%). The incidence rate of wildfire was the highest in sprout soybean (25.0%), followed by Daewon (24.7%) and Seoritae (5.4%). Meanwhile, in Uram, the incidence rate of bacterial pustules (7.1%) was the lowest, and this variety was not affected by bacterial blight or wildfire.

• Research in Plant Disease
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• v.28 no.4
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• pp.195-203
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• 2022

Zea mays, known as maize or corn, is a major staple crop and an important source of energy for humans and animals, thus ensuring global food security. Approximately 9.4% of the loss of total annual corn production is caused by pathogens including fungi, bacteria, and viruses, resulting in economic losses. Although the use of fungicides is one of the most common strategies to control corn diseases, the frequent use of fungicides causes various health problems in humans and animals. In order to overcome this problem, an eco-friendly control strategy has recently emerged as an alternative way. One such eco-friendly control strategy is the use of beneficial microorganisms in the control of plant pathogens. The beneficial microorganisms can control the plant pathogens in various ways, such as spatial competition with plant pathogens, inhibition of fungal or bacterial growth via the production of secondary metabolites or antibiotics, and direct attack to plant pathogens via enzyme activity. Here, we reviewed microorganisms as biocontrol agents against corn diseases.

• Research in Plant Disease
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• v.12 no.3
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• pp.153-157
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• 2006

In 2005, average temperature was lower, and average rainfall was less than those of previous year. The diseases of rice, barley, pepper, chinese melon, apple and oriental pear were surveyed. Bacterial blight, bacterial grain rot, and panicle disease of rice, black rot of pear, and white rot and bitter rot of apple were severe. Especially, brown rot of rice occurred four times higher than those of previous year. Panicle blight of rice increased about 3 times, compared with the previous year, presumed that the higher rainy days, rainfall and RH promoted spread of the fungal pathogens to panicles of rice. The diseases of rice leaf blast, sudden wilt syndrome, downy mildew and powdery mildew of chinese melon in plastic greenhouse, and virus diseases of hot pepper occurred distinctly less than those of the previous year. Another diseases surveyed occurred similar or less.

• The Plant Pathology Journal
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• v.34 no.3
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• pp.191-198
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• 2018

Fast and accurate diagnosis is needed to eradicate and manage economically important and invasive diseases like fire blight. Loop-mediated isothermal amplification (LAMP) is known as the best on-site diagnostic, because it is fast, highly specific to a target, and less sensitive to inhibitors in samples. In this study, LAMP assay that gives more consistent results for on-site diagnosis of fire blight than the previous developed LAMP assays was developed. Primers for new LAMP assay (named as DS-LAMP) were designed from a histidine-tRNA ligase gene (EAMY_RS32025) of E. amylovora CFBP1430 genome. The DS-LAMP amplified DNA (positive detection) only from genomic DNA of E. amylovora strains, not from either E. pyrifoliae (causing black shoot blight) or from Pseudomonas syringae pv. syringae (causing shoot blight on apple trees). The detection limit of DS-LAMP was 10 cells per LAMP reaction, equivalent to $10^4$ cells per ml of the sample extract. DS-LAMP successfully diagnosed the pathogens on four fire-blight infected apple and pear orchards. In addition, it could distinguish black shoot blight from fire blight. The $B{\ddot{u}}hlmann$-LAMP, developed previously for on-site diagnosis of fire blight, did not give consistent results for specificity to E. amylovora and on-site diagnosis; it gave positive reactions to three strains of E. pyrifoliae and two strains of P. syringae pv. syringae. It also, gave positive reactions to some healthy sample extracts. DS-LAMP, developed in this study, would give more accurate on-site diagnosis of fire blight, especially in the Republic of Korea, where fire blight and black shoot blight coexist.