Elimination of Aster Yellow Phytoplasma from Dendranthema grandiflorum by Application of Oxytetracycline as a Foliar Spray

정봉남,최국선 한국식물병리학회 2002 Plant Pathology Journal Vol.18 No.2

showing stunt, rosette, and excessive branching were treated with a foliar spray of 400 mg/l oxytetracycline at three-day interval for 1, 2, 3 and 4 months. Two months after the final treatment, new shoots from the recovered chrysanthemums showed the recurrence of the disease symptoms. However, cuttings from chrysanthemums treated with oxytetracycline did not express any phytoplasma infection symptoms for more than 10 months. Also, chrysanthemums dipped in 100 mg/l oxytetracycline solution combined with a foliar spray of 400 mg/l oxytetracycline for 4 weeks showed the same results. Using an electron microscope, ultrathin sections of leaf midribs of chrysanthemum cuttings treated with oxytetracycline for 4 months did not show phytoplasma bodies 10 months after treatment. Nucleic acids from chrysanthemums, which did not express phytoplasma infection symptoms for more than 10 months, did not amplify 16S rRNA gene of phytoplasma by polymerase chain reaction. These results may have implications in the propagation of phytoplasma-free healthy stocks for a wide range of plant species.

마음공부에 참여한 부부의 관계변화에 관한 질적연구 :전환학습을 중심으로

정봉남,이재준 인하대학교 교육연구소 2019 교육문화연구 Vol.25 No.5

본 연구에서는 마음공부에 참여한 부부들의 전환적 경험을 관계 변화라는 측면에서 이해하고, 전환학습의 관점에서마음공부를 통한 관계의 변화과정을 분석하고자 하였다. 이를 위해 마음공부로 매달 정기적인 모임을 가지는 부부3쌍을 대상으로 마음일기와 개별인터뷰를 통해 자료를 수집하여 사례연구를 진행하였다. 연구결과 연구참여자들은갈등상황을 경계로 인식하고 자기점검을 통한 감정의 안정화를 경험한다. 이어서 일기기재와 회화를 통한 거리두기와일상수행의 요법을 통해 비판적 성찰을 경험하며 자기이해를 시작한다. 자기이해의 시작은 과거 갈등의 원인을 상대방에게 찾던 습관적인 생각의 흐름을 멈추게 하며, 부부간 대화, 마음공부 과정에서 이성적 담론의 경험은 성숙한 대화를가능하게 하고 인식의 전환을 촉진한다. 이러한 경험 속에서 개인에 대한 이해가 심화된다. 전환의 과정을 거치며연구참여자들은 공감과 지지, 자기 확신이라는 변화의 추진력을 얻어 불편했던 상황의 변화를 시도하고 새로운 대안을탐색하기 시작한다. 새로운 역할과 새로운 관계 맺기를 실천하면서 자신의 다면성을 인정하게 되고, 부부 관계에서도배우자의 다면성을 수용하며 관계의 성장을 경험한다. 연구참여자들은 관점의 전환이 이어지도록 갈등과 화해를반복하는 학습을 계속하며 부부관계의 부적·정적인 양면성을 수용하고 기준과 전제에 묶이지 않는 가족관계를 형성한다. 또한 자신의 다양한 역할과 관계를 실천해 가는 과정에서 서로의 다름을 인정하고 타인을 이해하며 인정하게 되는사회적 관계의 확장을 보인다. The purpose of this study is to show the transitional experience of couples who participated in the study of mind in terms of relationship change and to analyze the process of change of relationship through the mind training from the perspective of transformative learning. To this end, a case study was conducted by collecting data through diaries and individual interviews of three couples who have regular meetings every month. The results of the study turned out that participants recognize the conflict as a boundary and experience the stabilization of emotion through self-examination. After that, they start to understand themselves by reflecting critically through distancing and daily practice with journal and conversation. The self-understanding. stops the habitual flow of thoughts that have led the other party to the causes of past conflicts. The experience of rational discourse in the process of marital dialogue and mind training enables mature dialogue, promotes a shift in perception, and leads to deepening individual understanding. Throughout the process of transformation, the research participants gained momentum such as empathy, support and self-confidence, attempting to change uncomfortable situations, and starting to explore new alternatives. The research participants will recognize their various facets by practicing new roles and new relationships. In a marital relationship, the spouse's various facets are embraced and the relationship grows. Participants continue learning to continue changing their perspectives while repeating conflict and reconciliation, accept two sides of marital relations, and form family relationships that are not tied to habitual standards and premises. In the course of practicing their various roles and relationships, they show the expansion of social relationships that recognize each other's differences and understand others.

Viral Infection of Tissue Cultured Orchids and Evaluation of Damages

정봉남,윤주연,김미선 한국식물병리학회 2010 Plant Pathology Journal Vol.26 No.2

Most orchids are propagated by tissue culture. To survey the viral infection of tissue cultured Orchids,total RNA was extracted from in vitro Cymbridium and Phalaenopsis spp. collected from companies producing tissue-cultured orchids, and RT-PCR analysis was conducted with primer pairs specific to Cymbidium mosaic virus (CymMV) and Odontoglossum ring spot virus (ORSV), which are infecting wide range of orchid genera. The bulb size of Cymbidium infected with CymMV and ORSV was compared with healthy one at 10 months after planting in vitro orchids in the glasshouse. The CymMV or ORSV infection in 97 Cymbidium and 55Phalaenopsis plants was 84.5 and 89.1%, respectively. Mixed infection was found in 52.6 and 47.3% of Cymbidium and Phalaenopsis tested, whereas virus-free orchids were 15.5 and 10.9%, respectively. The CymMV and ORSV reduced the bulb size by 2.7-50% depending on the cultivars of Cymbidium. The both viruses caused yellowing, mottle and mosaic with or without necrosis in 4 Cymbidium cultivars.

우리나라 화훼류 파이토플라스마병의 특성

정봉남,정명일,최국선 한국식물병리학회 2011 식물병연구 Vol.17 No.3

Seven phytoplasma diseases have been occurred on floricultural crops in Korea : Ph-ch1 and Ph-ch2 of chrysanthemum, Ph-lily of lily, petunia flat stem-Korean (PFS-K) of petunia, poinsettia branch inducing-Korean (PoiBI-K) of poinsettia, statis witches’ broom-Korean (SWB-K) of statis and azalea witches broom (AWB). Classification of the seven phytoplasmal diseases based on 16S ribosomal RNA (rRNA) sequences showed that floricultural crop phytoplasma disease were widespread in order of aster yellow (AY), stolbur and X-disease in Korea. In phenotypic characters, the fasciation was occurred in both monocotyledon plant of lily and dicotyledon plants of petunia and poinsettia. Besides, the fascination was occurred in Ph-lily of stolbur,petunia PFS-K of AY and PoiBI-K of X-disease. This result indicated that phytoplasma classification based on 16S rRNA and symptoms are not consistently related. The comparison of 16S rRNA sequence of the seven floricultural crop phytoplasma with five tree phytoplasmal diseases of jujube witches’ broom, paulownia witches’ broom, wild jujube witches’ broom, mulberry dwarf, golden rain phytoplasma occurred in Korea showed as high as 88.5−99.9% homology. Among them, especially mulberry dwarf showed the highest homology with the seven floricultural crop phytoplasms. Based on this result, floricultural crop phytoplasmas were assumed to be transmitted by insect vectors from tree phytoplasmas in Korea. 초록우리나라에서 화훼류에 7종류의 파이토플라스마병이 발생하였다. 국화의 Ph-ch1과 Ph-ch2, 나리의 Ph-lily, 페튜니아의 petunia flat stem(PFS-K), 포인세티아의 poinsettia branch inducing(PoiBI-K), 스타티스의 statis witches' broom (SWB-K)과 아잘레아의 azalea witches broom(AWB) 등이다. 16S rRNA 유전자 염기서열을 기본으로 화훼류 파이토플라스마를 분류한 결과 우리나라에는 aster yellow(AY), stolbur와 X-disease 순으로 많이 발생하였다. 파이토플라스마의 특징적인 병징 가운데 하나인 대화증상은 단자엽 식물인 나리와 페튜니아, 포인세티아와 같은 쌍자엽식물에서 모두 발생하였다. 또한 대화증상은 stolbur 그룹의 Ph-lily, AY 그룹의 petunia PFS-K와 X-disease의 포인세티아 PoiBI-K에서 모두 나타났다. 이 결과는 16S rRNA 유전자 염기서열에 기초를 둔 파이토플라스마 분류와 증상과는 일관성있게 일치하지 않는다는 것을 알 수 있다. 우리나라 화훼류에서 발생한 7종의 파이토플라스마를 대추나무빗자루, 오동나무빗자루, 묏대추나무빗자루, 뽕나무 오갈 및 모감주나무파이토플라스마 등 5종의 수목 파이 토플라스마와 16S rRNA 유전자의 염기서열을 비교한 결과 88.5-99.9%의 매우 높은 상동성을 나타내었다. 특히 뽕나무오갈병 파이토플라스마는 PoiBI-K를 제외한 6종의 화훼류 파이토플라스마와 96.3-99.9% 가장 높은 상동성을 나타내었다. 이 결과로 우리나라 화훼류에 발생한 파이토플라스마병은 매개충을 통하여 수목으로부터 전염되었을 것으로 추정되었다.

First Report on Carnation vein mottle virus in Dianthus barbatus in Korea

정봉남,B.D. Kim,G.S.Choi,J.S.Kim 한국식물병리학회 2004 Plant Pathology Journal Vol.20 No.3

A potyvirus causing chlorotic mottle and yellow spots on leaves of Dianthus barbatus was isolated and identified as an isolate of Carnation vein mottle virus (CVMV). Purified preparations of Chenopodium quinoa infected with CVMV-K showed filamentous particles between 695 and 785 nm long. Many cytoplasmic inclusions were observed, and these consisted of pinwheels, dense bands, loops, and circles. The coat protein of CVMV-K was about 32 KDa in western blot analysis using a CVMV antibody. The nucleotide sequence of coat protein gene showed 97.6% homology with a Japanese isolate. The genome size of CVMV-K was about 9.0 kb by dsRNA analysis. These results indicate that the virus is an isolate of CVMV. This is the first report on CVMV in Korea.

Tomato spotted wilt virus Isolates Giving Different Infection in Commercial Capsicum annuum Cultivars

정봉남,최학순,양은영,조점덕,조인숙,최국선,최승국 한국식물병리학회 2012 Plant Pathology Journal Vol.28 No.1

Tomato spotted wilt virus (TSWV)-infected Capsicum annuum plants were collected from open fields during June to July in 2010. The TSWV isolates were designated as Gneung, Ghang-Kjj, Gchang-Njc, Ghae, and Pap. The nucleotide sequence of the nucleocapsid protein (N) and movement protein (NSm) of the five isolates was determined. The pathogenicity of the five isolates was determined on 14 C. annuum cultivars two times by using mechanical inoculation. The five isolates induced different response: Both Gneung and Gchang-Kjj did not infect any of the cultivars in the 2nd trial, while Gchang-Njc, Ghae and Pap infected 11, 6 and 13 of 14cultivars, respectively. The five isolates also were tested on Solanum lycopersicum breeding line TGC09-71 and three Nicotiana species. S. lycopersicum showed a similar response to the five isolates as did C. annuum. Both Gchang-Njc and Ghae infected systemically all three Nicotiana species tested. While both Pap and Gneung did not infect any of the Nicotiana species tested. In conclusion, five TSWV isolates induced different infection spectra in C. annuum cultivars, Nicotiana species and an S. lycopersicum breeding line. Amino acid sequence analysis of the NSm gene could not support or explain the different infection spectra of the five isolates. This study indicated that various isolates must be used as virus inocula for evaluation of C. annuum and S. lycopersicum cultivars in breeding programs for TSWV resistance.

Occurrence of Chrysanthemum stunt viroid in Chrysanthemum in Korea

정봉남,임진희,Seong Youl Choi,Jeong Soo Kim,Eun Jung Lee 한국식물병리학회 2005 Plant Pathology Journal Vol.21 No.4

Infection rate of Chrysanthemum stunt viroid (CSVd) in 64 commercial chrysanthemum cultivars cultivated in Korea ranged from 9.7 to 66.8%. Symptoms on leaves of CSVd-infected chrysanthemum included yellow spots,chlorosis, vein clearing, vein bending and crumpling. CSVd induced flower malformation in ‘Scot’, color change in ‘Sharotte’, and color breaking in ‘Sharon’. CSVd caused reduction of plant height, leaf size, flower size and the flowers number by 32-50%, 26-35%, 14- 36% and 14-75%, respectively. In conclusion, CSVd affected plant height, leaf size and flower quality in chrysanthemum plants.

Detection and Molecular Characterization of a Stolbur Phytoplasma in Lilium Oriental Hybirds

정봉남,정명일 한국식물병리학회 2003 Plant Pathology Journal Vol.19 No.2

Stolbur phytoplasma was detected from Lilium Oriental hybrids showing flattened stem and flower clustering. The presence of phytoplasma was demonstrated using polymerase chain reaction (PCR) assays with phytoplasma- universal (P1/P6) and stolbur phytoplasma-specific 16F1/R1-S primer pairs amplifying phytoplasma 16S rDNA regions. Nucleotide sequences of the phytoplasma 16S rDNA were determined. Nucleic acid extracted from lily amplified 1.5 kb DNA with a phytoplasma universal primer pair. In nested PCR, 1.1 kb PCR product was obtained using specific primer pair, indicating an isolate of stolbur phytoplasma. Nucleotide sequence of phytoplasma 16S rDNA reported in this study showed 99.5% and 99.1% identities with two known stolbur phytoplasmas (16Sr XII-A). Also, it exhibited a sequence homology of 98.0% with phormium yellow leaf (16Sr XII-B), and 97.9% with Australian grapevine yellows (16Sr XII-B). Meanwhile, it showed 98.1% identity with strawberry green petal phytoplasma, (16SrI-C), and 94.7 % with American aster yellows (16SrI-B). Homology percentage of the 16S rDNA nucleotide sequence suggests that this phytoplasma could be classified into the stolbur phytoplasma, subgroup A (16Sr XII-A), as a type strain stolbur.

Occurrence of Petunia Flattened Stem Caused by Phytoplasma

정봉남,Kun Yang Huh 한국식물병리학회 2008 Plant Pathology Journal Vol.24 No.3

This study describes a phytoplasmal disease occurring in Petunia leaves grown in the glasshouse of the National Horticultural Research Institute, Suwon, Korea. Abnormal growth like flattened stem with flower malformation or phyllody was observed from the plant. The DNA extracted from the diseased leaves was amplified using a universal primer pair of P1/P6 derived from the conserved 16S rRNA gene of Mollicutes giving the expected polymerase chain reaction (PCR) product of 1.5 kb. In the nested PCR assays, the expected DNA fragment of 1.1 kb was amplified with the specific primer pair R16F1/R16R1 that was designed on the basis of aster yellows (AY) phytoplasma 16S rDNA sequences. The 1.1 kb PCR products were cloned and nucleotide sequences were determined, and the sequences of the cloned 16S rRNA gene were deposited in the GenBank database under the accession no. of EU267779. Analysis of the homology percent of the 16S rDNA of PFS-K showed the closest relationship with Hydrangea phyllody phytoplasma (AY265215), Brassica napus phytoplasma (EU123466) and AY phytoplasma CHRY (AY180956). Phytoplasma isolated from the diseased Petunia was designated as Petunia flat stem phytoplasma Korean isolate (PFS-K) in this study. Flattened stem occurring in Petunia was confirmed as infection of AY group of phytoplasma by determination of 16S rRNA gene sequences of phytoplasma and microscopic observation of phytoplasma bodies. This is the first report on the phytoplasmal disease in Petunia in Korea.

Incidence of Coleus blumei viroid 1 in Seeds of Commercial Coleus in Korea

정봉남,최국선 한국식물병리학회 2008 Plant Pathology Journal Vol.24 No.3

A viroid was detected from symptomless Coleus blumei cultivar ‘Kong Scarlet’. It consisted of 249 nucleotides (GenBank accession no. EU410620), which was 100% identical to a Coleus blumei viroid 1 (CbVd 1) reported from China (GenBank accession no. DQ178399), indicating that the viroid was an isolate of CbVd 1. Attempts were made to determine if commercial Coleus seeds were infected with CbVd. Infection rates in seedlings of the 14 commercial cultivars of Coleus ranged from 0 to 100%. CbVd 1 caused discoloration and growth retardation in some cultivars, but is symptomless in others. These results indicated that Coleus in commercial markets in Korea is highly infected with CbVd.