• 원예과학기술지
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• 제33권5호
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• pp.806-806
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• 2015

• The Plant Pathology Journal
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• 제36권6호
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• pp.600-607
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• 2020

Phytophthora capsici Leonian is a major pathogen of pepper worldwide and few resistance sources to this pathogen have been identified so far. The goals of this study were to identify new sources of resistance against P. capsici in Capsicum landraces and analyze the relationship between the resistance indicator of plant symptoms and some plant phenotype parameters of plant height, stem width, leaf length and leaf width. Thirty-two landraces of pepper were collected from fourteen states in Mexico. From each population, 36 plants were inoculated with 10,000 zoospores of P. capsici under controlled conditions. This experiment was repeated twice. Out of the 32 landraces, six showed high level of resistance, four showed intermediate resistance and five showed low level of resistance when compared with the susceptible control 'Bravo' and the resistant control 'CM334', indicating that these landraces are promising novel sources of resistance to P. capsici. There was no correlation between the symptoms and plant phenotype parameters. However, these parameters were not affected in the group classified as highly resistant, indicating that P. capsici does not affect the growing of these resistant pepper landraces. The other resistant groups were significantly affected in a differently manner regarding their phenotype, indicating that this pathogen reduce their growth in different ways. This study reports novel resistance sources with great potential that could be used in breeding programs to develop new pepper cultivars with durable resistance to P. capsici.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.12-12
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• 2017

Genetic improvement in potato can be carried out through several approaches, as sexual crosses, somatic hybridization, mutation and genetic engineering. Although the approach is different, but the goal is the same, to get a superior cultivar. Mutation and genetic engineering are very interesting methods for genetic improvement of potato plants. Mutation by gamma-ray irradiation have been performed to get some new potato cultivars which are more resistant to disease and have higher productivity. We have carried out a mutation of some potato cultivars and obtained some excellent clones to be potentially released as new superior cultivars. By the mutation method, we have released one potato cultivar for the French fries industry, and we registered one cultivar of potato for chips, and two cultivar for vegetable potatoes. Actually we are doing multi-location trial for three clones to be released as new cultivars. Through genetic engineering, several genes have been introduced into the potato plant, and we obtained several clones of transgenic potato plants. Transgenic potato plants containing FBPase gene encoding for fructose bisphosphatase, have a higher rate of photosynthesis and higher tuber productivity than non-transgenic plants. This result suggests that FBPase plays an important role in increasing the rate of photosynthesis and potato tuber productivity. Some transgenic potatoes containing the Hd3a gene are currently being evaluated for their productivity. Over expression of the Hd3a gene is expected to increase tuber productivity and induce flowering in potatoes. Transgenic potato plants containing MmPMA gene encoding for plasma membrane ATPse are more tolerant to low pH than non-transgenic plants, indicating that plasma membrane ATPase plays an important role in the potato plant tolerance to low pH stress. Transgenic potato plants containing c-lysozyme genes, are highly tolerant of bacterial wilt diseases caused by Ralstonia solanacearum and bacterial soft rot disease caused by Pectobacterium carotovorum. Expression of c-lyzozyme gene plays an important role in increasing the resistance of potato plants to bacterial diseases.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.10-18
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• 1998

For improvement of plants in disease resistance, it is most important to elucidate the mechanism to perceive and respond to the signal molecules of invaders. A model system with pea and its pathogen, Mycosphaerella pinodes, showed that the fungal elicitor induced defense responses in all plant species tested but that the suppressor of the fungus blocked or delayed the expression of defense responses and induced accessibility only in the host plant. In the world, many researchers believe that the pathogens` signals are recognized only on the receptors in the plasma membranes. Though we found that the ATPase and polyphosphoinositide metabolism in isolated plasma membranes responded to these fungal signals, we failed to detect specific actions of the suppressor in vitro on these plasma membrane functions. Recently, we found that ATPase (NTPases) and superoxide generating system in isolated cell wall were regulated by these fungal signals even in vitro, especially, by the suppressor in a strictly species-specific manner and also that the cell wall alone prepared an original defense system. The effects of both fungal signals on the isolated cell wall functions in vitro coincide perfectly with those on defense responses in vivo. In this treatise, we discuss the key role of the cell wall, which is plant-specific and the most exterior organelle, in determining host-parasite specificity and molecular target for improvement of plants.

• Journal of Ginseng Research
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• 제35권1호
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• pp.1-11
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• 2011

Korean ginseng is a medicinally important perennial herb from the family Araliaceae. It has been cultivated for its highly valued medicinal properties for over 1,000 years in east Asian countries such as China, Korea, and Japan. Due to its longtime cultivation in shady areas, ginseng is frequently exposed to pathogenic infections. Plants protect themselves from microbial pathogens using an array of defense mechanisms, some of which are constitutively active, while others are activated upon pathogen invasion. These induced defense responses, controlled by defense-related genes, require tradeoffs in terms of plant fitness. We hypothesize that ginseng, as with other plants, possesses regulatory mechanisms that coordinate the activation of attacker-specific defenses in order to minimize fitness costs while attaining optimal resistance. Several classes of defense-related genes are induced by infection, wounds, irradiation, and other abiotic stresses. Both salicylates and jasmonates have been shown to cause such responses, although their specific roles and interactions in signaling and development are not fully understood in ginseng. This review summarizes possible defense-related genes in ginseng based on their expression patterns against biotic and abiotic stresses and describes their functional roles.

• Journal of Microbiology
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• 제41권1호
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• pp.1-6
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• 2003

The genetic relatedness of multidrug-resistant pneumococcal isolates of serotypes 19F and 23F was investigated. The DNA fragments digested with Sma I were resolved by pulsed-field gel electrophoresis (PFGE). PFGE analysis of 365. pneumoniae isolates showed 13 different patterns. Among 22 isolates of serotype 19F, 9 different PFGE patterns were present and 14 isolates of serotype 23F isolates represented 5 distinct PFGE patterns. Two isolates of serotype 19F and six isolates of serotype 23F shared the same PFGE pattern (Pattern I). Based on the genetic relatedness within the strains (one genetic cluster was defined as having more than 85% homology), we divided the pneumococcal strains into genefic clusters (Ⅰ, II, III, IV, V, and VI). The 22 strains of serotype 19F belonged to five distinct genetic clusters (I, II, III, IV, V and VI) and 14 strains of serotype 23F represented two genetic clusters (I and II ). These results showed that strains of serotype 19F are genetically more diverse than those of serotype 23F, Serotype 19F isolates with PFGE patterns H and I appeared to be less related to those of the remaining PFCE patterns (A to G) (less than 60% genetic relatedness), but those strains were genetically closely related with serotype 23f. These results suggest that the latter isolates originated from horizontal transfer of the capsular type 19F gene locus to 23F pneumococcal genotypes. In conclusion, the multidrug-resistant pneumococcal isolates of serotype 19f and 23F isolated in Korea are the result of the spread of a limited number of resistant clones.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.43-43
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• 2019

The collection, evaluation and conservation of crop germplasm have been treated as one of the basics to breeding program. An understanding of genetic relationships among germplasm resources is vital for future breeding process like yield, quality, and resistance. In the present study, EST-SSR markers were employed to assess the polymorphism and genetic diversity of 192 accessions of Proso millet preserved in the National Agrobiodiversity Center of RDA. We evaluated the efficiency of EST-SSR markers developed for proso millet species. A total of 98 alleles were detected with an average allele number of 4.5 per locus among 192 proso millet millet accessions using 22 EST-SSR markers. The averaged values of gene diversity ($H_E$) and polymorphism information content (PIC) for each EST-SSR marker were 0.362 and 0.404 within populations, respectively. Our results showed the moderate level of the molecular diversity among the proso millet accessions from diverse countries. A phylogenetic tree revealed three major groups of accessions that did not correspond with geographical distribution patterns with a few exceptions. The less correlation between the clusters and their geographic location might be considered due to their type difference. Our study provided a better understanding of genetic relationships among various germplasm collections, and it could contribute to more efficient utilization of valuable genetic resources. The EST-SSR markers developed here will serve as a valuable resource for genetic studies, like linkage mapping, diversity analysis, quantitative trait locus/association mapping, and molecular breeding.

• The Plant Pathology Journal
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• 제39권6호
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• pp.575-583
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• 2023

Fusarium root rot is an increasingly severe problem in soybean cultivation. Although several Fusarium species have been reported to infect soybean roots in Heilongjiang province, their frequency and aggressiveness have not been systematically quantified in the region. This study aimed to investigate the diversity and distribution of Fusarium species that cause soybean root rot in Heilongjiang province over two years. A total of 485 isolates belonging to nine Fusarium species were identified, with F. oxysporum and F. solani being the most prevalent. Pot experiments were conducted to examine the relative aggressiveness of different Fusarium species on soybean roots, revealing that F. oxysporum and F. solani were the most aggressive pathogens, causing the most severe root rot symptoms. The study also assessed the susceptibility of different soybean cultivars to Fusarium root rot caused by F. oxysporum and F. solani. The results indicated that the soybean cultivar DN51 exhibited the most resistance to both pathogens, indicating that it may possess genetic traits that make it less susceptible to Fusarium root rot. These findings provide valuable insights into the diversity and distribution of Fusarium species that cause soybean root rot and could facilitate the development of effective management strategies for this disease.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.117.1-117
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• 2003

Phytophthora blight, caused by P. capsici, is very important disease of pepper. Many fungicides to control of Phytophthora blight have been developed, but most of fungicides disappeared in short periods. Nowadays dimethomorph was known as one of the most effective to control of this disease. P. capsici isolates from pepper fields were collected and surveyed their growth in dimethomorph amended V8 medium in order to evaluate their fungicides resistance. The fungicide resistant isolates were not founded among them. Most of the sensitive isolates were inhibited perfectly in V8 medium amended with 10ppm dimethomorph. Mutants of P. capsici by dimethomorph, was grown very well in 250ppm. The difference of pathogenicity, colony morphology, drug response, RT-PCR results was identified between sensitive and resistance isolates. This study should be provided a basic information about the occurrence of dimethomorph resistant isolates and genetic changes in P. capsici population.

• 한국환경보건학회지
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• 제30권1호
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• pp.15-21
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• 2004

In an attempt to analyze the characteristics of domestic pathogenic strains of S. pneumoniae, the basic epidemiological charactristics of pathogenic strains such as their serotypes and frequency of penicillin resistance, and pattern of chromosomal DNA from PFGE(pulsed-field gel electrophoresis) were observed. For this study,56 strains of S. pneumoniae isolated from inpatients and outpatients in the four domestic university hospitals were collected from January to December in 1998. Among those strains, a total of 56 pathogenic strains from blood(39 isolates), cerebrospinal fluid(8 isolates) and other specimen(9 isolates) were selected and isolated. The penicillin resistance frequency of those 56 strains was identified with disk diffusion method with 66.1％. From the invasive strains, predominant serotypes were isolated in the order of 19F(12.5％), 23F(10.7%), 14(10.7%) and 9V(10.7％), totalling 45 percent. This experiment also used PFGE patterns to compare the correlations among genetic subtypes in several serotypes. The DNA fragments digested with Sma I and Apa I were resolved by PFGE. The PFGE patterns digested with Sma I were better than Apa I for analysis. In the DNA fragments digested with Sma 1, PFGE analysis of 56 S. pneumoniae isolates showed 25 different patterns. As a result, serotype was on the whole correlated to PFGE pattern on the ground that each different PFGE pattern by serotype was observed. This study can be utilized not only fur the study of incidence trend of domestic pneumococcal diseases but also as a useful basic data for the development of identification tool and treatment.