Pseudocercospora dendrobii에 의한 덴드로비움 검은잎마름병

권진혁,박창석 한국균학회 2002 韓國菌學會誌 Vol.30 No.2

2001년 경상남도 창녕군 남지읍 덴드로비움 재배포장에서 잎에 검은 잎마름 증상이 심하게 발생하였다. 병징은 아래 잎에 원형 또는 부정형의 점무늬가 생기며 표면은 옅은 갈색의 작은 함몰된 병반이 차차 증가하여 검게 변하면서 썩고 나중에 회색을 띤 검은색으로 말라죽으면서 낙엽이 된다. 조사한 포장에서 발생율은 64.8%이었다. 균사의 색깔은 짙은 올리브색이고, 분생자병은 옅은 회갈색을 띠며 5∼10개의 격벽을 가지고 분지하며 끝 부분이 가늘고 둔하다. 크기는 63∼164×3.2∼4.9㎛이었다. 분생포자는 옅은 올리브색이며 가늘고 긴 곤봉모양이며 곧거나 약간 굽으로 1∼5개 격벽을 가지며, 크기는 46∼98×3.2∼3.9㎛이었다. 균사 생육적온은 20℃이었다. 이 병원균의 병징 및 균학적 특징, 병원성을 검정한 결과, P. dendrobii에 의한 덴드로비움 검은잎마름병으로 명명하고자 제안한다. Sooty leaf blight was found on Dendrobium sp. in several farmers' fields located in Namji-eup, Changnyeong-gun, Gyeongnam province Korea in 2001. Symptoms of the disease appeared on leaves. Sooty leaf spots were started with amphigenous, subcircular to irregular spots, with light grayish brown to black color with definite margin lines on the upper surface of leaves. Infected leaves became defoliated and whole plants eventually were died. The infection rates of the disease in the surveyed area reached up to 64.8% in the early September. Conidiophores of the causal fungus were dark grayish brown in color, densely fasciculate, straight, curved to sinuous, branched, 5∼10 septate and 63∼164×3.2∼4.9 ㎛ in size. Conidia were pale to olivaceous in color, obclavatecylindric, straight to slightly curved in shape, 1∼5 septate and 46∼98×3.2∼3.9 ㎛ in size. The optimum temperature for mycelial growth of the fungus was 25℃. The fungus was identified as Pseudocercospora dendrobii on the basis of its mycological characteristics. This is the first report on sooty leaf light of Dendrobium sp. caused by Pseudocercospora dendrobii in Korea.

Scab of Tea (Thea sinensis) Caused by Cladosporium herbarum in Korea

Kwon, Jin-Hyeuk,Kang, Soo-Woong,Kim, Jeong-Soo,Park, Chang-Seuk The Korean Society of Plant Pathology 2001 Plant Pathology Journal Vol.17 No.6

In 2001, a black scab disease was observed in tea plant (Thea sinensis) cultivated in the hillsides of Hwngaemyon and Hadong-gun, Gyeongnam province, Korea. The disease symptoms initially appeared on leaves, green twigs and stems, showing small dark brown spots on the infected areas, which gradually expanded. A fungus was isolated from diseased leaves and green twigs. It grew readily on potato dextrose agar, forming dark green to dark gray colonies. The optimum temperature for mycelial growth was about 20$^{\circ}C$. The diameter of growing hyphae was 3.5-5.8 $\mu\textrm{m}$. Conidia were ellipsoidal, ovoid or subspherical, and mostly one-celled but occasionally septate. The size of one-celled and septate conidia were 3.7-12.4${\times}$3.4-5.2 $\mu\textrm{m}$ and 9.3-18.7${\times}$3.8-7.2 $\mu\textrm{m}$, respectively. Conidia were formed in long branched chains on the erected conidiophores, which were dark brown in color and 28.9-218.3${\times}$3.0-6.1 $\mu\textrm{m}$ in length. The fungus was identified as Cladosporium herbarum on the basis of its morphological characteristics. The black scab disease occurring in tea caused by Cladosporium herbarum has not been previously reported in Korea.

Pod Rot of Cowpea (Vigna sinensis) Caused by Choanephora cucurbitarum

Kwon, Jin-Hyeuk,Shen, Shun-Shan,Park, Chang-Seuk The Korean Society of Plant Pathology 2001 Plant Pathology Journal Vol.17 No.6

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.

Stem Rot of Strawberry Caused by Sclerotium rolfsii in Korea

Kwon, Jin-Hyeuk,Shen, Shun-Shan,Park, Chang-Seuk The Korean Society of Plant Pathology 2004 Plant Pathology Journal Vol.20 No.2

A destructive stem rot of strawberry (Fragaria x ananassa cv. Akihime) sporadically occurred in farmers' fields in Daegok-myon, Jinju city, Gyeongnam province in Korea. The infected plants showed stem and crown rot, with occasional blighting of the whole plant. White mycelia appeared on stems of infected clones and sclerotia formed on the old lesions near soil surface. The fungus formed white colony on PDA and showed maximum mycelial growth and sclerotial formation at $30^{\circ}C$. The fungus usually have many narrow hyphal strands, 2.6-10.0 $\mu\textrm{m}$ in width, in the aerial mycelium. Typical clamp connections were formed on the mycelium. Sclerotia were spherical and 1.0-2.4 mm in size. The fungus was repeatedly isolated from infected tissues and identified as Sclerotium rolfsii. Its patho-genicity was confirmed when inoculated onto straw-berry. This is the first report on the stem rot of strawberry caused by S. rolfsii in Korea.

Occurrence of Stem Rot of Disporum smilacinum Caused by Sclerotium rolfsii in Korea

Kwon, Jin-Hyeuk,Jee, Hyeong-Jin The Korean Society of Plant Pathology 2007 Plant Pathology Journal Vol.23 No.3

In 2005 and 2007, a basal stem rot of Disporum smilacinum caused by Sclerotium rolfsii occurred sporadically in a herb farm at Hamyang, Korea. The symptom initiated with water-soaking lesion and progressed into stem rot and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the lesion at early stage and a number of sclerotia were formed on the stem near the soil line. The sclerotia were globoid in shape, 1-3 mm in size and white to brown in color. The optimum temperature for the growth and sclerotia formation was 30 on PDA and the hyphal width was measured $3-8{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of symptom, mycological characteristics and pathogenicity to the host plant, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of D. smilacinum caused by S. rolfsii in Korea.

Corynespora Leaf Spot of Balsam Pear Caused by Corynespora cassiicola in Korea

Kwon, Jin-Hyeuk,Jee, Hyeong-Jin,Park, Chang-Seuk The Korean Society of Plant Pathology 2005 Plant Pathology Journal Vol.21 No.2

Corynespora leaf spot occurred severely on balsam pear (Momordica charantia) at Changwon, Gyeongnam province in Korea in November and December 2003. The causal fungus isolated from infected leaves of the plants grew well on potato dextrose agar showing gray to brown color. Solitary or catenary conidia of the fungus were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. The number of isthmus pseudosepta ranged from 4 to 20 and measured 36~186${\times}$8~19 ${\mu}m$ in size. Conidiophores were pale to light brown in color and measured 94~648${\times}$3~8 ${\mu}m$ in size. Optimal temperature for mycelial growth was $30{\circ}C$. On the basis of mycological characteristics and pathogenicity, the fungus was identified as Corynespora cassiicola (Berk. & Curt.) Wei. This is the first report on the corynespora leaf spot of M. charantia caused by C. cassiicola in Korea.

Occurrence of sclerotium rot of onion and garlic caused by Sclerotium rolfsii

Jin-Hyeuk Kwon,Jong-Tae Lee,Jin-Seong Moon,Seok-Han Yoon,Ju-Hee Baek,Mi-Jin Lee,Kwang-Pyo Hong 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Occurrence of Powdery Mildew on Safflower Caused by Sphaerotheca fuliginea in Korea

(Jin Hyeuk Kwon),(Soo Woong Kang),(Heung Su Lee),(Chang Seuk Park) 한국균학회 2000 Mycobiology Vol.28 No.1

N/A N/A

Occurrence of Sword bean Scab Caused by Cladosporium cucumerinum in Korea

(Jin Hyeuk Kwon),(Soo Woong Kang),(Chang Seuk Park) 한국균학회 2000 Mycobiology Vol.28 No.1

N/A N/A

First Report of Corynespora Leaf Spot in Pepper Caused by Corynespora cassicola in Korea

Kwon, Jin-Hyeuk,Kang, Soo-Woong,Kim, Jeong-Soo,Park, Chang-Seuk The Korean Society of Plant Pathology 2001 Plant Pathology Journal Vol.17 No.3

A corynespora leaf spot of pepper, which has not been reported previously in Korea, occurred severely at the major pepper cultivation area of Chinju, Gyeongnam province in 2001. Infection rate ranged from 48.2 to 84.7% in eight fields surveyed. The causal fungus was identified as Corynespora cassicola based on the following cultural and morphological characteristics. The fungi grew well on potato dextrose agar, showing gray to brown color with cultural age. Conidia formed solitary or catenary were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. They had 420 pseudoseptate and isthmus, and measured 42.7-197.6 x 9.3-$23.5\mu\textrm{m}$. Septate conidiophores were pale to light brown in color, and measured 116.5-836.0 x 4.2-$11.0\mu\textrm{m}$. Conidia germinated as a bi-polar type. Optimal temperature for mycelial growth and conidial germination was $30^{\circ}$ and 25-$30^{\circ}$, respectively. The fungus showed strong pathogenicity to pepper plant, and the symtoms on pepper by the artificial inoculation were similar to those observed in the field. This is the first report on the corynespora leaf spot on pepper (Capsium annuum) caused by Corynespora cassicola in Korea.