• Korean journal of applied entomology
• /
• v.31 no.3
• /
• pp.205-240
• /
• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• Microbiology and Biotechnology Letters
• /
• v.51 no.4
• /
• pp.555-558
• /
• 2023

Staphylococcus aureus is a prominent multidrug-resistant pathogen known for its resistance to a variety of antibiotics. To combat this, a wide range of antibiotics, including quinolones, is utilized. While the efficacy of quinolones against S. aureus has been established, the rise in quinolone-resistant strains, particularly in methicillin-resistant S. aureus (MRSA), has necessitated a shift in their usage patterns. Genomic sequencing plays a crucial role as it offers insights into the genetic mechanisms of resistance. Thus, we report the complete genome sequence of an oxolinic acid-resistant strain of S. aureus isolated from sweet potato leaves, a crop commonly cultivated in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.4
• /
• pp.439-451
• /
• 1982

In fact, rice cultivation technique from 1962 to 1970 was very slight, but this technique from 1970 to now was remarkably developed in Korea, it was due to development of high fretilizer responsive and lodging resistant variety, Tongil; ie. Ind. ${\times}$ Japonica remote-cross rice variety. The main factors of this development is as follow: Firstly the most farmer (more than 90%) used newly developed seedling growth method; polyethylene film covered protected nursery bed. Secondly date of transplanting (middle or late part. of May) was earlier 10-15days than before 1970. Thirdly new varieties were highly lodging resistant at high fertilizer level $(N-P_2O_5-K_2O:15-9-11 kg/l0a)$. However, this level is 50% increased one than it for Japonica varieties. At forth planting density increased up to 75-80 hills per $3.3m^2$. Added to these factors, farm labor shortage and wage increase due to economic development gave a chance for introduction of transplanting machine to farmer in 1977. It's use increased for 100, 800 ha in 1981. The most of farmers are using herbicides and weed control system dependoing on wood composition has been established and disseminated to farmer.

• Journal of Korea Foundry Society
• /
• v.33 no.3
• /
• pp.122-126
• /
• 2013

Recently, heat-resistant aluminum alloy has been re-focused as a downsizing materials for the internal combustion engines. Heat-resistant Al alloy development and many researches are still ongoing for the purpose of improving thermal stability, high-temperature mechanical strength and fatigue properties. The conventional principle of heat-resistant Al alloy is the precipitation of intermetallic compounds by adding a variety of elements is generally used to improve the mechanical properties of Al alloys. Heat resistant aluminum alloys have been produced by CrW homogeneous solid solution to overcome the limit of conventional heat resistant aluminum alloy. From EPMA, it is found that CrW homogeneous soild solution phases with the size of $50-100{\mu}m$ have been dispersed uniformly, and there is no reaction between aluminum and CrW alloy. In addition, after maintaining at high temperature of 573 K, there is no growth of hardening phase, nor desolved, but CrW still exists as a homogeneous solid solution.

• Korean Journal of Medicinal Crop Science
• /
• v.11 no.2
• /
• pp.167-170
• /
• 2003

'Jinsun', a new variety of safflower(Carthamus tinctoris L.), was developed by Kyonggi-do Agricultural Research and Extension Services in 2000. It was bred with pure line selection from Namwon local variety population. Jinsun is relatively resistant to Gleosporium carthami and has more flower head and higher ripened grain ratio. Its flowering date was June 22 in Hwaseong, Gyeonggido and contains more protein and linoleic acid relatively in grain compared with Cheongsu, check variety. Grain yield of Jinsun was 11% higher than Cheongsu.

• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.37-37
• /
• 2015

Kimchi cabbage (Chinese cabbage), radish and Cabbage are major Brassicaceae vegetables in Korea. Especially, we can easily develop whole plant from one microspore in Kimchi cabbage. To develop clubroot resistant doubled-haploid (DH) inbred lines, we pollinated a clubroot resistant turnip of 'IT 033820' with a Kimchi cabbage (Chinese cabbage) inbred of 'BP 079'. More than 85 DH inbred lines were developed from this combination. We screened about 400 materials including these DH inbred lines, commercial cultivars and breeding materials during 3 years using hydroponic system after inoculating single spore isolation race 4(SSI-04) inoculate. One inbred line derived from this combination selected as clubroot resistant and registered as 'Wonkyo20036ho'. We inoculated 26 DH inbred lines derived from 'Zoong-baek 2ho' using SSI-4, the percent of resistant plants varied from 0 to 83%. However the horticultural traits of highly resistant DH inbred line was poor. Thus we selected one DH line showing 77% resistant with yellow inner leaf and maid good head, was registered as 'Wonkyo20034ho'. Another DH inbred line derived from Korean variety of 'Wol-dong' showing 86% resistant was registered as 'Wonkyo20037ho'. Other DH inbred lines were derived from Chinese cultivar of 'Choon-hi-go-hang-wang' and 'Hwang-shim-zo48' showed 80 and 71% resistant, respectively, was also selected for registration. Even though DH inbred lines derived from turnip showed highly resistant to SSI-04 and provincial inoculate, they showed poor characteristics in horticultural traits. However, commercial seed companies showed interesting for adapting these DH inbred lines in commercial breeding.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.92-92
• /
• 2017

Bakanae disease is one of the most serious and oldest problems of rice production, which was first described in 1828 in Japan. This disease has also been identified in Asia, Africa, North America, and Italy. Germinating rice seeds in seed boxes for mechanical transplantation has caused many problems associated with diseases, including bakanae disease. Bakanae disease has become a serious problem in the breeding of hybrid rice, which involves the increased use of raising plants in seed beds. The indica rice variety Shingwang was selected as resistant donor to bakanae disease. One hundred sixty nine NILs, YR28297 ($BC_6F_4$) generated by five backcrosses of Shingwang with the genetic background of susceptible japonica variety, Ilpum were used for QTL analysis. Rice bakanae disease pathogen, CF283, was mainly used in this study and inoculation and evaluation of bakanae disease was performed with the method of the large-scale screening method developed by Kim et al. (2014). SSR markers evenly distributed in the entire rice chromosomes were selected from the Gramene database (http://www.gramene.org), and the polymorphic markers were used for frame mapping of a $BC_5F_5$ resistant line. Here, we developed 168 near-isogenic rice lines (NILs, $BC_6F_4$) to locate a QTL for resistance against bakanae disease. The lines were derived from a cross between Shingwang, a highly resistant variety (indica), and Ilpum, a highly susceptible variety (japonica). The 24 markers representing the Shingwang allele in a bakanae disease-resistant NIL, YR24982-9-1 (parental line of the $BC_6F_4$ NILs), were located on chromosome 1, 2, 7, 8, 10, 11, and 12. Single marker analysis using an SSR marker, RM9, showed that a major QTL was located on chromosome 1. The QTL explained 65 % of the total phenotype variation in $BC_6F_4$ NILs. The major QTL designated qBK1 was mapped in 91 kb region between InDel15 and InDel21. The identification of qBK1 and the closely linked SSR marker, InDel18, could be useful for improving rice bakanae disease resistance in marker-assisted breeding.

• Korean journal of applied entomology
• /
• v.14 no.4 s.25
• /
• pp.214-214
• /
• 1975

This study was conducted to evaluated the nature of the variety Tongil(Suweon 213-1) in resistance to the striped rice borer, Chilo suppressalis Walker, comparing with those of Rexoro(susceptible check) and TKM-6(resistant check) selected at IRRI. 1. The striped rice borer moths much more preferred the variety Tongil for oviposition than the varieties Rexoro and TKM-6. The variety Tongil and more egg masses and number of eggs than the varieties Rexoro and TKM-6, while TKM-6 having more egg masses and more number of eggs than Rexoro. This reaction was consistent throughout the test regardless of the number of tillers per hill. 2. In laboratory, preference of larvae for feeding was studied with 5cm of stem pieces of the varieties. The results showed, in contrast to the case of ovipositional preference, that the striped rice borer larvae least preferred the stems of Tongil among the test varieties, while larvae much more preferred the stems of Rexoro than those of TKM-6. 3. The larval weights at 20 days later infested on the 40 day-old plants were the lowest on Tongil among the test varieties. On the variety Rexoro the larvae had heavier body weights(43.0mg), higher pupation(64.9%) and higher adult emergence(83.3%) than those on Tongil(larval weights 30.3mg, pupation 60%, adult emergence 60.7%) and TKM-6(larval weights 35.7mg, pupation 56.3%, adult emergence 51.9%). The pupal weights, however, were not consistent among the test varieties and/or sexes in comparison with the larval weights, pupation and adult emergence above mentioned. 4. Field experiments indicated that the incidence of dead hearts at 70 days after transplanting was relatively higher on the variety Tongil(11.1%) than those on Rexoro(8.9%) and TKM-6(8.4%), and the incidence of white heads at harvest was, in contrast to the dead hearts, lower on Tongil(9.8%) than those on Rexoro(27.4%) and TKM-6(13.9%). At harvest lower larval survival observed on Tongil (49 larvae/40 hills) than those on the susceptible variety Rexoro(104 larvae/40 hills) and on the resistant variety TKM-6(70 larvae/40 hills). The average larval weights collected from three test varieties at harvest were 80.5mg from Tongil, 83.7mg from TKM-6 and 99.6mg from Rexoro. 5. Increased nitrogen fertilizer application to the variety Tongil, the striped rice borer damage was increased. Also, preference of larvae for feeding significantly increased with the increase of nitrogen fertilizer application. 6. Any specific association between the plant characters and striped rice borer resistance could not be found. The variety Tongil even having large number of tillers, short plant height, large stem, broad leaf, etc, had still high preference of moths for oviposition, low preference of larvae for feeding, low damage, and relatively high antibiosis. 7. Resistance of the variety Tongil to the striped rice borers seemed to be associated with the low feeding preference and the relatively high antibiosis, not associated directly with the ovipositional preference.

• Korean journal of applied entomology
• /
• v.1
• /
• pp.37-41
• /
• 1962

Fifty three varieties of potatoes were planted at Alpine Potato Research station at Takwalyong Kangwando Province since in 1962. The varieties planted were introduced front Japan, the United States and Germany. The varietal reaction was divided into five classes, and the results were following. Immune : Kennebec, Isola, Cherokee, Merrimack, Yoraku, Lisili. Cosima. Highly Resistant : Antze, Ragis Isola, Hessenkrone, Plymouth, Sebago, Pungo, Sieglinde, Anco, Essex. Resistant : Tawa, B-605-10, Sequoia, Grata, Concordia, Onaway, Holing 1. Nisego. Susceptible: Nordak, Pontiac, Benimaru, Early Gem, Chippewa, Chitose, Ohjiro, Red Bake, Norland, Katahdin. Highly Susceptible: Russet Burbunk, May Queen, Earlaine, Irish Cobbler, Feldeslohn, Red Warba, Chisago, Osseo, Paunee. Warba, Norgleam, Red Beauty, Red Burt, Danshaku, Namchak (Native variety), In general the verieties introduced from the United States and Germany were more resistant to late blight than those introduced from Japan. Especially the German varieties were immune or highly resistant to the disease except Feldeslohn. Early maturing varieties were more susceptible to late blight than the late maturing varieties in southern Korea.

• Journal of the Korean Society of Tobacco Science
• /
• v.19 no.1
• /
• pp.11-17
• /
• 1997

A flue-cured tobacco variety (Nicotiana tabacum cv. Wisconsin) was used for Plant transformation with the complementary DNA (cDNA) of potato virus Y-necrosis strain (PVY-VN) replicase gone (Nb) which was synthesized through reverse-transcription Primed with oligo(dT) and Polymerization using RNase H-digested template. The cDNA was cloned into Plant expression vector Plasmid (PMBP2), and introduced into tobacco plants by co-culturing tobacco leaf disks with Agrobacterium tumefaciens LBA4404 containing the plasmid before Plant regeneration. Eight Plants, in which the inserted cDNA fragment was detected by Polymerase chain reaction (PCR), out of 70 putative transformants inserted with sense-oriented Mb cDNA showed no symptom at 3 weeks after inoculation, while the other 62 plants, and all plants with vector gone only and antisense-oriented NIb cDNA had susceptible vein-necrosis symptoms. However, only 2 of the 8 resistant plants were highly resistant, which remained symptomless up to 10 weeks after inoculation. Among the first progenies (T1) from self-fertilized seeds of the two resistant transgenic plants, less than 10 % of 71 plants appeared highly resistant (with no symptom), 70% moderately resistant (with mild symptoms on 1 - 2 leaves), and about 20% susceptible (with susceptible symptoms on 3 or more leaves) at 3 weeks after inoculation. These results suggest that the PVY resistance was inherited in the 71 generation. Key words : potato virus Y. viral replicase gene, transgenic tobacco Plants, resistance.