• The Plant Pathology Journal
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• v.37 no.2
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• pp.99-114
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• 2021

Tan spot of wheat, caused by Pyrenophora tritici-repentis (Ptr), results in a yield loss through chlorosis and necrosis of healthy leaf tissue. The major objective of this study was to compare gene expression in resistant and susceptible wheat cultivars after infection with Ptr ToxA-producing race 2 and direct infiltration with Ptr ToxA proteins. Greenhouse experiments included exposure of the wheat cultivars to pathogen inoculum or direct infiltration of leaf tissue with Ptr-ToxA protein isolate. Samples from the experiments were subjected to RNA sequencing. Results showed that ToxA RNA sequences were first detected in samples collected eight hours after treatments indicating that upon Ptr contact with wheat tissue, Ptr started expressing ToxA. The resistant wheat cultivar, in response to Ptr inoculum, expressed genes associated with plant resistance responses that were not expressed in the susceptible cultivar; genes of interest included five chitinases, eight transporters, five pathogen-detecting receptors, and multiple classes of signaling factors. Resistant and susceptible wheat cultivars therefore differed in their response in the expression of genes that encode chitinases, transporters, wall-associated kinases, permeases, and wound-induced proteins, among others. Plants exposed to Ptr inoculum expressed transcription factors, kinases, receptors, and peroxidases, which are not expressed as highly in the control samples or samples infiltrated with ToxA. Several of the differentially expressed genes between cultivars were found in the Ptr resistance QTLs on chromosomes 1A, 2D, 3B, and 5A. Future studies should elucidate the specific roles these genes play in the wheat response to Ptr.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.652-661
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• 2021

Xanthomonas citri pv. glycines (Xcg) is a major pathogen of soybean (Glycine max) in South Korea, despite the availability of soybean varieties with some resistance. We conducted a nationwide survey of the incidence and severity of bacterial pustule caused by Xcg. The percentage of infected fields was 7% to 17% between 2015 and 2017. We characterized the diversity of a nationwide collection of 106 Xcg isolates based on avrBs3 banding patterns. The isolates fell into 11 groups, each represented by a type strain; only two of these were similar to isolates collected from 1999 to 2002. The diversity of Xcg strains increased and the dominant strains changed between 1999 and 2017, with three new type strains comprising 44% of the isolates examined in 2012 to 2017. Pathogenicity tests did not show evidence for a shift in the races or aggressiveness of Xcg strains. Korean soybean cultivars, including the widely-grown Daewon cultivar, were susceptible to the 11 new type strains. The cultivar CNS, which carries the rxp resistance gene, was susceptible to most type strains, including two representing 83% of the Korean Xcg strains. In contrast, Williams 82, which also carries rxp, showed resistance to at least five type strains. Collectively, these results suggest that Williams 82 has resistance loci in addition to rxp. The widespread distribution of Xcg, the high virulence of the current endemic strains, and the low resistance of most Korean soybean cultivars collectively favor widespread disease in Korea in years that are favorable to pustule development.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.23-23
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• 2022

Rapeseed (Brassica napus L.) is one of the most valuable oilseed crop in the world. It is widely used in various industries, such as food, animal feed, energy and chemical industries. In order to improve the industrial requirements for rapeseed, useful agronomic characteristics (higher yields and disease resistance etc.) and modified oil traits (fatty acid composition and fat content) are important in rapeseed. However, Korea has limiting genetic resources of novel traits in rapeseed. In this research, novel rapeseed mutant genotypes by mutation breeding was developed. The mutant lines were generated by the treatment of the seeds of the original cultivar 'Tamra' with 700 Gy of gamma-ray (⁶⁰Co). Mutants showing varied in flowering time, crude fat content, seed yield and fatty acid content that exhibited stable inheritance of the mutated characteristics from M₅ to M₇ generations were selected. We investigated genetic variation using SNPs identified from GBS analysis in rapeseed mutant lines derived from the gamma-ray, and interactions between the major agronomic and the oil traits. Significantly associated SNP loci were explored along with candidate genes using SNPs obtained by GBS analysis. As a results of association mapping, a total of 322 SNPs were significantly associated with agronomic traits (155 SNPs) and oil traits (167 SNPs). A total of 70 genes were annotated from agronomic characteristics SNPs; among them 7 genes significantly enriched in developmental process, and a total of 70 genes were annotated from crude fat content and fatty acid compositions SNPs; among them, 11genes were significantly enriched in biosynthetic process. These results could be used for the selection of rapeseed cultivar with enhanced qualities and potential economic benefits.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.257-260
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• 1998

Anthocyanins pigments were isolated from the pigmented rice seeds (cultivar Killimhuk-mi) by a combination of Sephadex LH-20 and preparative high performance liquid chromatographies. Four anthocyanins were identified by their chromatographic, spectral and chemical properties. The major pigment was cyanidin 3-glucoside and cyanidin 3-oxalyl-glucoside was found in the rice for the first time.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.158-161
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• 2006

Main tobacco diseases were surveyed on major flue-cured leaf tobacco fields throughout South Korea in 2006. Mosaic caused by potato virus Y and bacterial wilt caused by Ralstonia solanacearum were most severe during harvest season. During last ten years, the damage by tobacco mosaic virus was reduced but the incidence of bacterial wilt increased. These changes of the disease incidences coincide with release time of the tobacco cultivar resistant to the tobacco mosaic virus but susceptible to bacterial wilt pathogen. Wild fire(Pseudomonas syringae pv. tabaci strain ungulate) occurred severely at Kangwon province, though the symptom of wild fire with yellow halo was not observed.

• Research in Plant Disease
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• v.10 no.2
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• pp.87-93
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• 2004

Rhizome rot of ginger, caused by Pythium myriotylum, a major limiting factor for its production, has occurred annually, but become severe, especially in hot and humid years with frequent rainfalls in Korea. Most studies on rhizome rot have been carried out since 1980s in the National Institute of Agricultural Sciences and Technology, Honam Crop Experimental Station and Choongnam Provincial Rural Development Administration. Many aspects of rhizome rot, such as survey of the disease incidence, taxonomy, pathogenicity and physiology of pathogen, and ecology of soilborne inocula have been studied in the researches. However, intensive studies have been concentrated on management technologies of the disease including seed-rhizome disinfection, soil sterilization, evaluation of cultivar resistance, and fungicide application, and most developed technologies have been used in commercial farmings. In future, development of resistant varieties and simple soil disinfection technologies applicable in Korean condition and economically feasible fungicide application technology have to be developed for better management.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.25-31
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• 2018

This study analyzed factors influencing cultivation area of two major apple cultivars, Fuji and Hongro, applying the panel SUR model to survey data from farms. Characteristics of farms, distribution factors, and weather factors were the independent variables of the model. The analysis indicated that characteristics of farms, distribution factors, and weather factors influence the cultivation area of Hongro and Fuji. The independent variables were also found to have different levels of influence on increase and decrease of the cultivated area. Helping predict changes in cultivation area of Hongro and Fuji, the research results can be used as primary data to support efforts to prevent price fluctuations due to changes in supply.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.381-384
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• 2006

This study was conducted to selected Korean black raspberry (Rubus coreanus Miq.) for high productivity. The eight major agronomic traits were investigated from 198 clones of the clone bank established in Korea Forest Research Institute, Suwon, Korea. The selection levels based on number of fruit per fructify lateral (NFFL) over 20, and fruit weight (FW) over 1.3g, and yield of individual per fructify lateral (YIFL) over 25g, were applied on 198 clones, resulted in 17 clones selected. The selected superior trees, 17 clones, appeared regional differences for amount of fruiting among 4 different test sites. When number of fruit per fruit petiole (NRFP), fruit weight (FW), yield of individual (YI) and sugar content were satisfied over 20, 1.4g, 6kg and 9.5 brix, respectively, as a select condition, 5 clones were reselected as the superior trees among 17 clones. for 3 years.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.39-44
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• 2002

This paper was studied on a strategy in rice production under New round system of WTO(World Trade Organization) in Korea. Under enactment of New round system in WTO rice will be opened at the world market and thus rice growers will compete with this marketing system. In this regard, rice industry in Korea would be "a theory of rice triangle" such as high quality, low cost, and environmental friendly system. High quality rice would be obtained through a cultivar, cultivation technology, and quality control(QC) to compete against oversea's dealer. Lower cost in rice production should be concentrated into rapid decrease in rural population and into introducing for young generation. Rice cultivation has been played major role in this peninsula in terms of a preservation of water resource, fresh air and prevention of soil erosion.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.611-615
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• 2011

'Manjong' is a new japonica rice cultivar developed in 2009 derived from a cross between 'Yeongdeog34' and 'Nampyeongbyeo' at the Department of Functional Crop, NICS, RDA. This cultivar is suitable for the double cropping system after the cash crop cultivation. Heading date of 'Manjong' is later than 'Keumobyeo' under the late transplanting cultivation on July 10. It has high grain fertility under cold conditions and low premature heading. One of the distinguishing characteristics of this variety is its resistance to major diseases like leaf blast and rice stripe virus disease. However, it shows susceptibility to major insect pests and bacterial blight disease. Milled rice kernels are translucent with non-glutinous endosperm and have 7.2% protein and 18.7% amylose contents. Ripening ratio and head rice ratio is very higher than those of 'Keumobyeo'. The palatability of cooked rice is also better than 'Keumobyeo'. The milled rice yield of 'Manjong' in local adaptability tests after harvest of the cash crop is $4.81MT\;ha^{-1}$. This cultivar is suitable for planting in the plain paddy fields of Honam and Yeonnam regions in Korea.