• The Plant Pathology Journal
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• v.25 no.2
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• pp.113-120
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• 2009

Microscopic study of chili pepper (Capsicum annuum L.) infected with Phytophthora capsici, causing Phytophthora blight of chili pepper, was conducted to compare histological and cytological characteristics in the root and stem of susceptible (C. annuum cv. Bugang) and resistant (C. annuum cv. CM334) pepper cultivars. The susceptible pepper roots and stems were extensively penetrated and invaded by the pathogen initially into epidermal cells and later cortical and vascular cells. Host cell walls adjacent to and invaded by the infecting hyphae were partially dissolved and structurally loosened with fine fibrillar materials probably by cell wall-degrading enzymes of the pathogen. In the resistant pepper, the pathogen remained on root epidermal surface at one day after inoculation, embedded and captured in root exudation materials composed of proteins and polysaccharides. Also the pathogen appeared to be blocked in its progression at the early infection stages by thickened middle lamellae. At 3 days after inoculation, the oomycete hyphae were still confined to epidermal cells of the root and at most outer peripheral cortical cells of the stem, resulting from their invasion blocked by wound periderms formed underneath the infection sites and/or cell wall appositions bounding the hyphal protrusions. All of these aspects suggest that limitation of disease development in the resistant pepper may be due to the inhibition of the pathogen penetration, infection, invasion, and colonization by the defense structures such as root exudation materials, thickened middle lamellae, wound peridems and cell wall appositions.

• Korean Journal of Breeding Science
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• v.43 no.2
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• pp.139-144
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• 2011

Fifty-five sweet pepper (Capsicum annuum L.) germplasm from the Rural Development Administration (RDA) were analyzed for their fruit yield and fruit quality characters, including fruit weight, fruit size, pericarp thickness, total soluble content, fruit lobe, fruit shape, fruit surface and fruit color. Fruit yield per plot ranged from 200 g to 8150 g (average, 1884 g). Fruit fresh-weight per fruit ranged from 27.3 g to 200.0 g with an average of 97.2 g. Fruit length varied from 4.0 cm to 16.2 cm (average, 9.6 cm). Fruit length-to-width ratio ranged from 0.6 to 3.0 with an average 1.7. The fruit pericarp thickness ranged from 1.8 mm to 10.7 mm (average, 4.8 mm). Total soluble content was the highest ($8.5^{\circ}Brix$) in K156286 and the lowest ($5.3^{\circ}Brix$) in K156208 with the average value $6.7^{\circ}Brix$. Fruit lobes numbers varied from 2 to 4. Blocky, triangular, elongated, rectangular and round fruit shape identified among the sweet pepper accessions. Fruit surface varied from smooth to wrinkle and fruit color also varied. The presence of variability in fruit yield and quality traits within the sweet pepper genotypes can be utilized to develop high yielding sweet pepper variety with better fruit quality characters.

• Journal of Plant Biology
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• v.39 no.3
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• pp.167-172
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• 1996

Efficient plant regeneration has been achieved via organogenesis in the red pepper plant (Capsicum annum L.). Shoots were induced from seed explants of cultivar 'Friendship' on Murashige and Skoog's (MS) basal medium supplemetned with; NAA or IAA, and BAP or zeatin. Seed explants on the medium supplemented with 0.1-0.3 mg/L IAA and 2-5 mg/L zeatin for 2 weeks vigorously formed normal shoots in more than 90% of the explants. When these were transferred to MS medium containing 0.5-1.0 mg/L GA, 90-100% of the shoots have elongated within 1-2 weeks. The elongated shoots rooted in media supplemented with 0.3 mg/L NAA. It was revealed that this method is very rapid and efficient regeneration system for red pepper and regenerated plants can be obtained after only 5-6 weeks of culture.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.527-539
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• 2023

Pepper (Capsicum annuum L.) is an important vegetable and spice crop that has been cultivated worldwide. Pepper fruits have unique taste and aroma, providing a variety of antioxidants and compounds important for human health, which makes a high economic value. In addition, there is a high demand for new pepper varieties, according to consumer's preference. However, pepper is a recalcitrant plant for in vitro tissue and organ differentiation and plant regeneration, which makes it difficult to develop demanded varieties using newly developed technologies such as genetic engineering and gene editing. In this study, tissue culture and regeneration conditions were investigated using seven pepper varieties that were obtained from the core-collection of Seoul National University. We observed callus and bud induction and shoot formation using several media composition composed of different cytokinins and auxin concentrations. As a result, it was found that there were differences in callus induction and shoot formation of each variety depending on the hormone composition, and the highest regeneration was shown when the medium containing Zeatin Riboside and the petioles of seedlings were used. In particular, out of seven pepper varieties, CMV980 exhibited a higher regeneration efficiency (approximately 48%) than other varieties, followed by Yuwolcho. Therefore, this study provides CMV980 and Yuwolcho as good candidates that can be used for pepper transformation, which might contribute to the development of various varieties through gene editing technology in the future.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.10-19
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• 2012

This study investigated the distribution of endophytic fungi obtained from the surface sterilized tissues of leaves, stems and roots of chili pepper ($Capsicum$ $annuum$ L.) plants in seedling, flowering and fruiting stages in Korea and their antifungal activity. A total of 481 isolates were recovered and were identified using molecular techniques. Based on rDNA ITS gene sequence and phylogenetic analysis, 21 fungal genera were characterized, belonging to 16 Ascomycota and 5 Basidiomycota. $Penicillium$ in seedling stage, $Fusarium$ in flowering stage, $Colletotrichum$ followed by $Fusarium$, $Alternaria$ and $Xylaria$ in fruiting stage was predominant and $Alternaria$, $Cladosporium$ and $Fusarium$ were common in all growth stages. Among 481 endophytes 90 phenotypes were evaluated for the antimicrobial activity against three major pathogens ($Phytophthora$ $capsici$, $Colletotrichum$ $acutatum$ and $Fusarium$ $oxysporum$) of chili pepper. Among them 16 isolates inhibited the growth of at least one test microorganisms. Three strains showed a broad spectrum antifungal activity and displayed strong inhibition against chili pepper pathogenic fungi.

• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.143-149
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• 2000

An Efficient in vitro regeneration system and an optimized Agrobacterium mediated transformation protocol are described, based on the use of young seedling cotyledons of Capsicum annuum L. Optimal regeneration efficiency can be obtained by cultivating cotyledon explants on media containing 4 mg/L benzyladenine and 0.1 mg/L indolacetic acid. The effect of antibiotics used to eliminate Agrobacteria, as well as the toxic level of some generally used selection agents (kanamycin, geneticin, hygromycin, phosphinotricin and methotrexate) in regenerating pepper tissues were determined. To enable the comparison of different selection markers in identical vector background, a set of binary vectors containing the marker genes for NPTII, HPT, DHFR and BAR respectively, as well as the CaMV 35S promoter/enhancer-GUS chimaeric gene was constructed and introduced into four different Agrobacterium host strains.

• Plant Resources
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• v.4 no.1
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• pp.26-30
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• 2001

To improve the iron content of red pepper, we have transferred the entire coding sequence of the ferritin gene(Fpl) into Capsicum annuum (L. cv. Chungyang and Bukang) by Agrobacterium mediated transformation. Transformants were found to contain the Fp1 gene at up to three loci, increased distinct iron content changes. In transgenic plants, iron content was as much as 7-fold to 8-folds greater than that of their untransformed counterparts. Furthermore, the Rl progenies from transformant(A7, A8) co-segregated into a 15:1 ratio for both Kanamycin resistance and genotype of high iron.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.741-743
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• 1998

A bacterial disease of pepper (Capsicum annuum L.) that rooted the stem nodes to black was found in pepper plants which cultivated in plastic house at Chungdo, Kyungpook, Korea in March, 1998. Bacterial isolates derived from the diseased peppers were pathogenic to potato, eggplant and Chinese cabbage but, was not pathogenic to chrysanthemum by artificial inoculation. On the basis of bacteriological characteristics and pathogenicity test on host plants, the causal organism of the node soft rot of pepper is identified as Erwinia carotovora subsp. carotovora and the name of disease is proposed as bacterial node soft rot of pepper.

• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.92-96
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• 1999

To study the regulatory mechanism of isoprenoid (carotenoid) biosynthesis, we have compared the expression patterns of nine isoprenoid biosynthetic genes in Korean red pepper (Capsicum. annuum cv. NocKaung). The expression of geranylgeranyl pyrophosphate synthase gene was initially induced at early ripening stage (I1) and was rather slightly decreased during pepper fruit ripening. The ex-pression of phytoene synthase gene was strongly induced at semi-ripening stage (I2) and the phytoene desaturase transcript was maximally induced at the fully ripened stage (R). Our results suggest that genes encoding two 3-hydroxy-3-methylglutaryl-CoA reductase isozymes (HMGR1 and HMGR2) and farnesyl pyrophosphate synthase might be not so critical in pepper carotenoid biosynthesis but three genes encoding geranylgeranyl pyrophosphate synthase, phytoene synthase and phytoene desaturase were induced in a sequential manner and coordinately regulated during the ripening of pepper fruit.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.80.2-81
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• 2003

Since hot peppers (Capsicum annuum L.) are getting reputation as an important source of vitamins, medicine and many other areas, consumption and cultivation is being increased in the world. In spite of this usefulness, so little attention has been given to the hot pepper plants. To date, less than 500 nucleotide sequences including redundancy has been identified in NCBI database. Therefore we started to EST sequencing project for initial characterization of the genome, because of the large genome size of hot pepper (2.7 3.3 ${\times}$ 109 bp), To date, a set of 10,000 non-redundant genes were identified by EST sequencing for microarray-based gene expression studies. At present, cDNA microarrays containing 4,685 unigene clones are used for hybridization labeled targets derived from pathogen infected and uninoculated leaf tissues. Monitoring of gene expression profiles of hot pepper interactions with soybean pustule pathogen (Xag；Xanthomonas axonopodis pv. glycine) will be presented.