• The Plant Pathology Journal
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• 제26권2호
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• pp.149-153
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• 2010

Biological and structural mechanisms of the nematode disease development in chili pepper caused by the root-knot nematode, Meloidogyne incognita, were investigated. Out of 39 chili pepper cultivars/lines tested, six were found resistant, while 33 were susceptible to M. incognita, of which a susceptible cultivar Chilseongcho and three resistant cultivar/lines CM334, 02G132 and 03G53 with different resistance degrees were selected for microscopic studies on the disease development. Gall formation was greatly reduced in the resistant cultivars/lines. Nematode penetration occurred both in the susceptible and resistant chili pepper roots; however, the penetration rates were significantly lowered in the three resistant peppers compared to the susceptible pepper cv. Chilseongcho. In the susceptible pepper, giant cells were extensively formed with no discernible necrosis around the nematode feeding sites. In the highly resistant pepper cultivar CM334, no giant cell was formed, but extensive necrosis formation was observed around the penetrating nematodes. In the other two resistant pepper lines (02G132 and 03G53), both giant cells and prominent necroses were formed, and the necrotic responses appeared to inhibit the further development of giant cells or accelerate their early degeneration. Although the nematode penetration was retarded significantly in the resistant cultivar/lines, all of the above results suggest that the disease resistance of pepper may be related to post-infectional defense mechanisms (nematode growth and development) more than pre-infectional ones (penetration and establishment). Variations in structural modifications in the resistant cultivar/lines may reflect their genetic differences related to the nematode resistance.

• 한국균학회지
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• 제40권4호
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• pp.277-281
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• 2012

고추포장의 토양에서 분리한 Bacillus sp. NAAS-1 Colletotrichum acutatum에 대한 생물학적 방제 활성을 검정 하였다 이 분리균주를 일종의 작물보호제인 카밴다짐 가스가마이신 수화제와 비교하여 검정한 결과, 기준사용량 농도(50 ${\mu}L/mL$)와 비슷한 항진균 활성을 나타냈다. 또한 생물 검정 결과, 공시 작물보호제의 기준사용량 농도(50 ${\mu}L/mL$)에서 보다 고추 탄저병균의 발병억제효과가 높게 나타나내었다.

• The Plant Pathology Journal
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• 제25권2호
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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.

• The Plant Pathology Journal
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• 제34권1호
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• pp.1-10
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• 2018

A previously unreported bacterial disease on chili pepper (Capsicum annuum L.) seedlings affecting as many as 4% of seedlings was observed in greenhouses in Chihuahua, Mexico (Delicias and Meoqui counties). Initial lesions appeared as irregular small spots on leaves and brown necrosis at margins tips were observed. Later, the spots became necrotic with a chlorotic halo. Advanced disease was associated with defoliation. A Gram negative, rod-shaped bacterium was isolated from diseased chili pepper seedlings. Three inoculation methods revealed that isolated strains produce foliage symptoms, similar to those observed in naturally infected seedlings. Pathogenic strains that caused symptoms in inoculated seedlings were re-isolated and identified to fulfill koch's postulate. Polyphasic approaches for identification including biochemical assays (API 20E and 50CH), carbon source utilization profiling (Biolog) and 16S rDNA, hsp60 and rpoB sequence analysis were done. Enterobacter cloacae was identified as the causal agent of this outbreak on chili pepper seedlings.

• The Plant Pathology Journal
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• 제28권1호
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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.

• 한국응용곤충학회지
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• 제49권1호
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• pp.23-29
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• 2010

토마토나 고추 등의 유용작물에 자주 발생하여 생산량을 저하시키는 오이모자이크병에 대한 저항성을 높여 생산량을 증대시키기 위하여 개발된 CMVP0-CP (Cucumber mosaic virus-coat protein) gene이 삽입된 유전자 변형 CMVP0-CP 고추 (line 7)에 대한 환경위해성을 평가하였다. 2007년 고추의 생육기간 동안 절지동물의 군집구조를 3회(6월 19일, 7월30일, 8월 31일)에 걸쳐 조사를 하였다. 두 가시의 고추, 즉 모본(P915, nTR)고추와 유전자변형 고추(CMVP0-CP (line 7), TR)의 꽃과 잎에 서식하는 곤충을 포함한 절지동물의 군집구조를 파악하기 위하여 곤충을 포획할 수 있는 곤충진공포획기를 사용하여 절지동물을 정량적으로 채집하였다. 절지동물의 군집은 채집 시기별로 출현 종과 빈도수에 차이는 있었지만 두 작물간의 군집 구조는 통계학적으로 차이를 나타내지 않았다. 지금까지 수행된 본 연구결과를 근거로 판단하여 볼 때, 유전자 변형 고추로 인한 비표적 생물체의 군집구조가 모본 고추의 군집구조와 차이가 나타나지 않아 환경 위해서도 없는 것으로 볼 수 있지만, 좀더 확실한 유전자변형생물체인 고추의 환경위해성이 없다는 결론을 얻기 위해서는 추가적인 연구가 수행되어져야 할 것이다.

• The Plant Pathology Journal
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• 제32권4호
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• pp.311-320
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• 2016

Xanthomonas axonopodis pv. glycines (Xag) is a necrotrophic bacterial pathogen of the soybean that causes bacterial pustules and is a nonhost pathogen of the chili pepper. In the current study, chili pepper fruit wound inoculated in planta with Xag 8ra formed necrotic lesions on the fruit surface and induced several structural and chemical barriers systemically in the fruit tissue. The initial defense response included programmed cell death of necrotizing and necrotized cells, which was characterized by nuclear DNA cleavage, as detected by TUNEL-confocal laser scanning microscopy (CLSM), and phosphatidylserine exposure on cell walls distal to the infection site, as detected by Annexin V FLUOS-CLSM. These two responses may facilitate cell killing and enhance transportation of cell wall materials used for cell wall thickening, respectively. The cells beneath the necrotic tissue were enlarged and divided to form periclinal cell walls, resulting in extensive formation of several parallel boundary layers at the later stages of infection, accompanying the deposition of wall fortification materials for strengthening structural defenses. These results suggest that nonhost resistance of chili pepper fruit against the nonhost necrotrophic pathogen Xag 8ra is activated systematically from the initial infection until termination of the infection cycle, resulting in complete inhibition of bacterial pathogenesis by utilizing organspecific in situ physiological events governed by the expression of genes in the plant fruit organ.

• 식물병연구
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• 제23권4호
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• pp.334-347
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• 2017

Ralstonia solanacearum에 의한 고추 풋마름병은 고추의 생산량 감소에 영향을 미치는 주요 병해 중 하나이다. 그리고 병 저항성 작물을 재배하는 것은 고추의 풋마름병 방제에 가장 효과적인 방제 방법이다. 본 연구는 고추의 풋마름병 저항성을 효율적으로 검정하기 위한 방법을 개발하기 위하여 수행되었다. 풋마름병에 대한 저항성 및 감수성 6개 고추 품종을 선발하고, 다양한 조건에서 이들 품종의 풋마름병 발생을 조사하였다. 접종 방법에 따른 고추 품종들의 풋마름병 발생 정도를 실험한 결과, 상처없이 토양관주하는 방법과 접종원에 뿌리를 침지하는 방법보다 뿌리 절단 후 접종원을 관주하는 방법이 더 간단하고 효율적이었다. 풋마름병 저항성 계통인 'MC4'는 파종 후 21일부터 28일 재배한 고추 유묘에 $1{\times}10^8cfu/ml$ 농도의 세균 현탁액을 포트 당 20 ml 접종하였을 때 가장 높은 저항성을 나타냈다. 한편 감수성 품종들은 이들 조건에서 높은 감수성을 보였다. 이들 결과는 우리가 고추 품종의 풋마름병에 대한 효율적인 저항성 검정방법을 개발하였다는 것을 나타낸다. 그리고 선발한 발병조건을 사용하여 시판중인 140개 고추 품종의 풋마름병에 대한 저항성 정도를 평가하였다.

• Mycobiology
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• 제41권1호
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• pp.18-24
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• 2013

Two new species of endophytic fungi were encountered during a diversity study of healthy tissues of chili pepper plants in Korea. The species were identified as Paecilomyces inflatus and Bionectria ochroleuca based on molecular and morphological analyses. Morphological descriptions of these endophytic isolates matched well with their molecular analysis. In the present study, detailed descriptions of internal transcribed spacer regions and morphological observations of these two fungi are presented.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2006년도 한국육종학회 공동심포지엄 및 학술대회
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• pp.17.1-17.1
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• 2006