• 식물병연구
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• 제19권2호
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• pp.95-101
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• 2013

Xanthomonas campestris pv. campestris(Xcc)에 의한 검은썩음병은 세계적으로 배추과 작물에 발생하여 큰 피해를 주고 있는 주요 식물병이다. Xcc에 대한 양배추의 효율적인 저항성 검정법을 확립하기 위해, Xcc에 대한 저항성 정도가 서로 다른 '루비아', '오조라', '그린핫', 'Saint', 'Joeun-ACE', 'Wonderball' 및 'XCCR 500' 등 7개 양배추 품종을 대상으로 접종 방법, 접종 위치, 재배 기간 그리고 재배 온도에 따른 검은썩음병 발생을 조사하였다. 양배추 품종들의 저항성은 18핀이나 가위를 사용하여 접종하는 것보다 핀셋(mouth-tooth forceps)을 사용하여 접종하였을 때 가장 큰 차이를 보이며, 직접적으로 엽맥에 접종하는 것보다 엽맥 주변에 접종이 더 효과적이었다. 그리고 접종한 유묘를 $30^{\circ}C$ 보다 $22^{\circ}C$에서 재배하였을 때에 감수성과 저항성 반응이 더 분명하게 나타났다. 이상의 결과로부터 양배추 검은썩음병에 대한 효과적인 저항성 검정법으로 4주 재배한 유묘의 엽맥 주변을 핀셋(mouth-tooth forceps)으로 상처 접종한 후 $22^{\circ}C$ 생육상에서 재배하는 방법을 제안하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.785-793
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• 2019

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is the most damaging disease in Brassica crops around the world. In this study, we developed a molecular marker specific to Xcc race 5. To do this, the available whole genome sequences of Xcc races/strains and Xc subspecies were aligned and identified a highly variable genomic region (XccR5-89.2). Subsequently, a primer set covering the 'XccR5-89.2' region was designed and tested against the genomic DNA of Xcc races/strains, Xc subspecies and other plant-infecting bacterial strains (Pseudomonas syringae pv. maculicola and Erwinia carotovora subsp. carotovora). The results showed that the 'XccR5-89.2' primer pair amplified a 2,172-bp fragment specific to Xcc race 5. Moreover, they also amplified a 1,515-bp fragment for Xcc race 1 and an over 3,000-bp fragment for Xcc race 3. However, they did not amplify any fragments from the remaining Xcc races/strains, subspecies or other bacterial strains. The 'XccR5-89.2' primer pair was further PCR amplified from race-unknown Xcc strains and ICMP8 was identified as race 5 among nine race-unknown Xcc strains. Further cloning and sequencing of the bands amplified from race 5 and ICMP8 with 'XccR5-89.2' primers revealed both carrying identical sequences. The results showed that the 'XccR5-89.2' marker can effectively and proficiently detect, and identify Xcc race 5 from Xcc races/strains, subspecies and other plant-infecting bacteria. To our knowledge, this is the first report for an Xcc race 5-specific molecular marker.

• The Plant Pathology Journal
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• 제38권4호
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• pp.272-286
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• 2022

Black root rot (BRR) caused by Lasiodiplodia theobromae is an alarming disease of mulberry that causes tremendous economic losses to sericulture farmers in India and China. Successful control of this disease can be attained by screening germplasm and identifying resistant sources. Seventy four diseased root samples were collected from farmer's fields belonging to four major mulberry growing states of South India. Based on morpho-cultural and scanning electron microscopy studies, 57 fungal isolates were characterized and identified as L. theobromae. Phylogenetic analysis of concatenated internal transcribed spacer and β-tubulin sequences revealed variation of the representative 20 isolates of L. theobromae. Following the root dip method of inoculation, pathogenicity studies on susceptible mulberry genotypes (Victory-1 and Thailand male) recognized the virulent isolate MRR-142. Accordingly, MRR-142 isolate was used to evaluate resistance on a set of 45 diverse mulberry accessions. In the repeated experiments, the mulberry accession ME-0168 which is an Indonesian origin belonging to Morus latifolia was found to be highly resistant consistently against BRR. Eight accessions (G2, ME-0006, ME-0011, ME-0093, MI-0006, MI-0291, MI-0489, and MI-0501) were found to be resistant. These promising resistant resources may be exploited in mulberry breeding for developing BRR resistant varieties and to develop mapping populations which successively helps in the identification of molecular markers associated with BRR.

• The Plant Pathology Journal
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• 제24권2호
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• pp.118-124
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• 2008

Skin sooty dapple disease, a fungal disease that lowers Asian pear fruit quality, has emerged recently in Korea but has not yet been thoroughly characterized. This disease affects the surface of fruit, leaves, and young shoots of the Asian pear, typically appearing as a dark or pale black dapple on the fruit surface. The disease initiates on the fruit with small circular lesions that become bigger, eventually spreading to form large circular or indefinite lesions. Sparse dark or flourishing white-greyish aerial mycelia and appearance of a dark or pale black dapple on the fruit surface are typical signs of this disease. The disease was severe during cold storage of the Niitaka and Chuhwangbae varieties, but more limited on the Gamcheonbae and Hwangkeumbae varieties. To identify causal pathogens, 123 fungal isolates were obtained from lesions. The fungi that caused typical skin sooty dapple disease symptoms in our bioassay were identified. Based on their morphological characteristics, 74% of the isolates were Cladosporium sp. and 5-7 % of the isolates were Leptosphaerulina sp., Tripospermum sp., or Tilletiopsis sp. None of the isolates caused severe soft rot by injection to a wound plug, but some of the Cladosporium sp. isolates caused mild maceration. Therefore this microbiol complex cannot account for the soft rot also observed in stored fruits. The high frequency of isolation of Cladosporium sp. from disease tissues and bioassay on pear fruit surface suggest that Cladosporium sp. could be a major pathogen in the microbial complex associated with skin sooty dapple disease of the Asian pear in Korea.

• Mycobiology
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• 제32권2호
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• pp.98-101
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• 2004

A fruit soft rot caused by Mucor piriformis occurred on sweet persimmon storages in Jinju, Changwon and Gimhae, Gyeongnam province, Korea, 2003. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies on potato dextrose agar at $20^{\circ}C$ were whitish to olivaceous-buff Sporangia were globose, black and $96{\sim}153{\mu}m$ in size. Sporangiophores were $26{\sim}42{\mu}m$ in width. Sporangiospores were ellipsoid and $5.8{\sim}10.6{\times}4.3{\sim}7.6{\mu}m$ in size. Columella was obovoid, cylindrical-ellipsoidal, pyriform, subglobose and $80{\sim}125{\mu}m$ in size. Optimal temperature for mycelial growth was $20^{\circ}C$ on PDA. The causal organism was identified as M. piriformis. This is the first report of fruit soft rot on sweet persimmon caused by M. piriformis in Korea.

• 식물병연구
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• 제11권2호
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• pp.204-207
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• 2005

2003년부터 2005년까지 경남 창원시 대산면 북부마을 여주재배 농가에서 Rhizopus stolonifer에 의한 여주 무름병이 발생하였다. 병징은 처음 과실껍질 부분이 수침상으로 물러지면서 빠르게 부패되었다. 균사생육 적온은 $25^{\circ}C$ 내외로 처음 흰색에서 연한 갈색으로 되며 검은색의 포자낭을 많이 형성한다. 포자낭경은 처음 흰색에서 회색을 나타내며 포자낭을 균사 끝에 형성하고 폭은 $15\~30{\mu}m$ 이었다. 포자낭은 처음에 흰색에서 나중에 검은색으로 되었고 모양은 반구형으로 크기는 $90\~180{\mu}m$이었다. 주축의 모양은 반구형으로 크기는 $80\~150{\mu}m$이었다. 포자낭포자는 담갈색으로 단포이며 구형 또는 타원형으로 불규칙한 것이 많으며 크기는 $7\~18{\times}6\~12{\mu}m$이었다. 이상과 같은 병원균의 균학적 및 병원학적 특성조사 결과로 본 병해를 Rhizopus stolonifer (Ehrenberg ex. Fr.) Lind에 의한 여주 무름병으로 명명할 것을 제안한다.

• The Plant Pathology Journal
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• 제17권6호
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• pp.354-356
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• 2001

In August 2001, pod rot of cowpea caused by Choanephora cucurbitarum was found in the experimental fields of the Gyeongsangnam-do Agricultural Research and Extension Services, Korea. Initial symptoms of the disease were the appearance of water-soaked, dark-green lesions and followed by rapid rotting of the infected tissues. As the disease progressed, whitish mycelia and monosporous sporangiophore with monosporous sporangiola were produced on the lesions. The fungus produced white to pale yellowish brown mycelia with scattered monosporous sporangiophore and monosporous sporangia containing sporangiospores on potato dextrose agar (PDA). Monosporous sporangiophore was long, slender and branched at the apex, with each branch bearing a sporangiospore. Sporangium was subglobose in shape and 42.6-112.6 ㎛ in size. Monosporous sporangiola were elliptic, fusiform or ovoid, brown in color, and 9.8-23.4$\times$7.2-12.8 ㎛ in size. Sporangiospores were elliptic, fusiform or ovoid in shape, dark brown or brown in color, 12.9-24.6$\times$8.6-15.4 ㎛ in size, and had three or more appendages. Zygospores were black and 43.6-72.4 ㎛ in size. The fungus grew on PDA at 15-40$\^{C}$, and optimum temperature was 30$\^{C}$. This is the first report on pod rot of cowpea caused by C. cucurbitarum in Korea.

• 식물병연구
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• 제8권2호
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• pp.113-116
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• 2002

A sclerotinia rot of Leonurus sibiricus caused by Sclerotinia sclerotio겨m occurred severely in farmer's fields at Seosang-myon, Hamyang-gun, Gyeongnam Province, Korea in 2001. The typical symptoms of the disease were that leaves, stems or collar of the infected plants at first became darker green and then watery soft rotted, and white fluffy mycelia formed on the lesion developed into black sclerotia later, Sclerotia on the plant and PDA medium were globose to cylindrical or irregular in shape, and 0.8~10.3$\times$0.8~6.4 m in size. Aphothecia with numerous asci were cup-shape, and 0.6~1.2 cm in diameter, Asci with 8 spores were cylindrical, and 87~246$\times$4.6~21.6 $\mu\textrm{m}$ in size. Ascospores of one cell were hyaline, ellipsoid to ovoid in shape, and 10.2~14.6$\times$4.7~7.2 $\mu\textrm{m}$ in size. The range of temperature for mycelial growth was from 5 to 3$0^{\circ}C$, and the optimum was $25^{\circ}C$. This is the first report on the sclerotinia rot of L. sibiricus caused by Sclerotinia sclerotioum in Korea.

• 한국균학회지
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• 제30권2호
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• pp.166-169
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• 2002

2002년 진주시 농산물 도매시장에서 Rhizopus stolonifer에 의한 감귤 무름병이 발생하였다. 병징은 처음 과일 껍질 부분이 수침상으로 물러지면서 급속히 진전되어 썩었다. 균사는 처음 흰색에서 연한 갈색으로 되며 검은색의 포자낭을 형성한다. 포자낭병은 처음 무색에서 회색을 나타내며 포자낭을 끝에 만들고 길이는 $900{\sim}4300{\mu}m$였다. 포자낭은 처음에 무색에서 나중에 검은색이고 아구형으로 크기는 $98{\sim}346{\mu}m$이다. 추축은 아구형 또는 타원형으로 직경은 $60{\sim}216{\times}72{\sim}143{\mu}m$이다. 포자낭포자는 담갈색으로 단포이며 구형 또는 타원형으로 크기는 $8{\sim}18.3{\mu}m$였다. 균사생육 적온은 $25^{\circ}C$였다. 이상과 같이 병원균의 균학적 특징과 병원성을 검정한 결과 이병을 R. stolonifer에 의한 감귤 무름병으로 명명할 것을 제안하고자 한다.

• Mycobiology
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• 제29권3호
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• pp.176-178
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• 2001

A soft rot of fruits caused by Rhizopus stolonifer occurred on cherry tomato in Jinju City Agricultural Products Wholesale Market, Korea. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and were rapidly softened and diseased lesion gradually expanded. The mycelia grew vigorously on the surface of fruits and formed stolons. Colonies on potato dextrose agar at $25^{\circ}C$ were white cottony at first, becoming heavily speckled by the presence of sporangia and the browinish black, and spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were $82.7{\times}196.7{\mu}m$ in size and globose or sub-globose with somewhat flattened base. The color of sporangia was white at first and then turned black with many spores, and never overhanging. Sporangiophores were $2.6{\sim}5.8{\times}12.3{\sim}24.2{\mu}m$ in width, smooth-walled, non-septate, tight brown, simple, long, arising in groups of $3{\sim}5$ from stolons opposite rhizoids. Sporangiospores were $8.2{\sim}18.8{\mu}m$ long, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was $64.1{\times}136.3{\mu}m$. brownish gray, and umberella-shaped when dehisced. The causal organism was identified to be R. stolonifer. This is the first report of Rhizopus soft rot on cherry tomato caused by R. stolonifer in Korea.