1.Occurrence of Sword bean Scab Caused by Cladosporium cucumerinum in Korea.
Jin Hyeuk KWON ; Soo Woong KANG ; Chang Seuk PARK
Mycobiology 2000;28(1):54-56
A black scab disease occurred on sword bean (Canavalia gladiata) in plastic film houses around Chinju area during the spring season of 1999. The disease started from flower bud, then moved to flower stalk, pod, petiole, cirrus, stem and leaves. The lesions started with small dark brown spots then were gradually expanded. Severely infected plants reached 37.4% of whole plant covered with scab. Numerous conidia were produced on the diseased flower disk, pod, floral axis, stem and leaves. Most of the conidia were appeared to be readily dispersed in the air, but the mycelia were not suggested causing of sooty mold by ectoparasitism. A fungus was isolated from the diseased stem, and inoculated to healthy plants to satisfy the Koch's postulates and proved the fungus was the causal agent of the disease. The isolated fungus grew on potato dextrose agar, forming greenish black to pale brown colonies. Conidia were ellipsoidal, fusiform or subspherical, mostly one-celled but occasionally septated. The conidia were 3.9~34.1x2.7~5.1microm in size and formed in long branched chains on the erected conidiophores which were pale olivaceous brown and variable in length between 7.2~210.7microm in size. Ramoconidia were 7.6~29.2x3.2~14.4microm in size. The fungus was identified as Cladosporium cucumerinum based on the above morphological characteristics. The optimum temperature for mycelial growth and conidial formation was about 15 to 25degrees C. Cladosporium scab of sword bean caused by the fungi has not been reported in Korea previously.
Agar
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Axis, Cervical Vertebra
;
Cladosporium*
;
Flowers
;
Fungi
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Glucose
;
Gyeongsangnam-do
;
Korea*
;
Plants
;
Plastics
;
Seasons
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Solanum tuberosum
;
Spores, Fungal
2.Occurrence of Rhizopus Soft Rot on Peach (Prunus persica var. vulgaris) Caused by Rhizopus nigricans in Korea.
Jin Hyeuk KWON ; Soo Woong KANG ; Chang Seuk PARK
Mycobiology 2000;28(4):177-179
A soft rot of fruits caused by Rhizopus nigricans occurred on peach (Prunus persica var. vulgaris ) in The Chinju City Agricultural Products Wholesale Marke during in summer season of 2000. The disease infection usually started from wounding after harvest fruits, and then moved to outside. At first, the lesions started with water soaked and rapidly softened and diseased area gradually expanded. In severely infected film house, the rate of infected fruits reached 65.2%. Numerous sporangiospores were produced on the diseased fruits. Most of the sporangiospores were appeared to be readily dispersed in the air. The mycelia grew surface of fruits and produced stolons. Colonies on potato dextrose agar at 25~30degrees C white cottony at first becoming heavily speckled by the presence of sporangia and the browinish black at maturity, spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were 85.3~243.5x53.4~219.2microm in size and were 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 over-hanging. Sporangiophores were 8.9~36.6microm in width, smooth-walled, non-septate, light brown, simple, long, arising in groups of 3~5 from stolons opposite rhizoids. Sporangiospores was 9.7~24.8x5.9~15.8microm, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was 70.2x149.7microm. brownish gray, and umberella-shaped when dehisced. The causal organism was identified as. Rhizopus nigricans Lind on the basis of the morphiogical characteristics of the fungus. Rhizopus soft rot on peach (Prunus persica ) caused by the fungi has not been reported in Korea. This is the first report of rhizopus soft rot on peach caused by Rhizopus nigricans in Korea.
Agar
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Fires
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Fruit
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Fungi
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Glucose
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Gyeongsangnam-do
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Korea*
;
Prunus persica*
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Rhizopus*
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Seasons
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Solanum tuberosum
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Sporangia
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Spores
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Water
;
Wounds and Injuries
3.Occurrence of Strawberry Scab Caused by Cladosporium herbarum in Korea.
Jin Hyeuk KWON ; Soo Woong KANG ; Jeong Soo KIM ; Chang Seuk PARK
Mycobiology 2001;29(2):110-112
A black scab was observed on strawberry(Fragaria ananassa) in plastic film houses around Jinju area during the winter of 2000. The disease started from leaves then moved to calyx and runner. At the beginning, the infected area started with small dark brown spots then gradually expanded. The pathogenic fungus was purely isolated from the diseased leaves, calyx and runner. The fungus was inoculated to test Koch's postulates and proved to be the causal agent of the disease. The isolated fungus grew readily on potato dextrose agar, forming dark green to dark gray colonies. The optimum temperature for mycelial growth was about 25degrees C. The diameter of growing hyphae was 3.8~5.6 microm. Conidia were ellipsoidal, ovoid or subspherical, mostly one-celled but occasionally septate. The size of conidia were 4.1~11.7x3.8~5.3 1-cell, 9.3~18.8x4.0~7.4 microm 2-cell and formed in long branched chains on the erected conidiophores which were dark brown and variable in length between 28.8~236.2x3.0~6.2 microm in size. The fungus was identified as Cladosporium herbarum on the basis of its morphological characteristics. The black scab disease of strawberry caused by C. herbarum has not been reported in Korea previously.
Agar
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Cladosporium*
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Fragaria*
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Fungi
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Glucose
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Gyeongsangnam-do
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Hyphae
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Korea*
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Plastics
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Solanum tuberosum
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Spores, Fungal
4.Occurrence of Stem Rot of Wild Aster (Aster koraiensis) Caused by Sclerotium rolfsii in Korea.
Jin Hyeuk KWON ; Soo Woong KANG ; Shun Shan SHEN ; Chang Seuk PARK
Mycobiology 2001;29(1):58-60
A destructive stem rot of wild aster (Aster koraiensis) occurred sporadically some farmers' fields in Guman-myon, Kosong-gun, Kyongsangnam-do in 2000. One of the most severely infected field in Kosong showed 28.6 percent of infection rate. The fungus also caused stem or crown rot and systemic wilt or blight of the plants. White mycelium spread over stems and petioles of infected plants and sclerotia formed on the old lesions and near the soil surface. The fungus showed maximum mycelial growth around 30degrees C and did not grow under 5degrees C and over 45degrees C and mycelial width were 4.3~10.2 microm. Colony was white, usually many narrow mycelial stand in the aerial mycelium and formed clamp connection. Numerous sclerotia were formed on PDA at 30degrees C. The shape sclerotia were globoid and 0.8~3.0x0.9~3.4 mm in size. The fungus was isolated repeatedly from the infected tissues and confirmed its pathogenecity to wild aster and identified as Sclerotium rolfsii. This is the first report on the stem rot of wild aster caused by S. rolfsii in Korea.
Crowns
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Fungi
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Gyeongsangnam-do
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Korea*
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Mycelium
;
Soil
5.Occurrence of Powdery Mildew on Safflower Caused by Sphaerotheca fuliginea in Korea.
Jin Hyeuk KWON ; Soo Woong KANG ; Heung Su LEE ; Chang Seuk PARK
Mycobiology 2000;28(1):51-53
The powdery mildew of safflower (Carthamus tinctorius L.) extensively occurred at 1999 at the experimental farm of Kyongsangnam-do Agricultural Research and Extension Services. Both sides of the leaves and the older stems were covered with the fungus, and then the leaves and stems turned yellow. The conidia, conidiophores and perithecia were observed on the leaf lesion. Perithecia were ellipsoidal, 80-117microm in diameter. Asci were subglobose and 84~99x59~73microm in size. Ascospore were ellipsoidal to ovoid, and 15~34x11~23microm in size. Conidia were ellipsoid to barrel-shaped, 25~37x11~22microm in size and formed in long chains. The causal organism was identified as Sphaerotheca fuliginea. This is the first report on powdery mildew of safflower caused by Sphaerotheca fuliginea in Korea.
Carthamus tinctorius*
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Fungi
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Gyeongsangnam-do
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Korea*
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Spores, Fungal
6.Stem Rot of Garlic (Allium sativum) Caused by Sclerotium rolfsii.
Mycobiology 2010;38(2):156-158
Stem rot disease was found in garlic (Allium sativum L.) cultivated from 2008 to 2010 in the vegetable gardens of some farmers in Geumsan-myon, Jinju City, Gyeongnam province in Korea. The initial symptoms of the disease were typical water-soaked spots, which progressed to rotting, wilting, blighting, and eventually death. White mycelial mats had spread over the lesions near the soil line, and sclerotia had formed over the mycelial mats on the stem. The sclerotia were globoid in shape, 1~3 mm in size, and tan to brown in color. The optimum temperature for growth and sclerotia formation on potato dextrose agar (PDA) medium was 30degrees C. The diameter of the hyphae ranged from approximately 4 to 8 microm. Typical clamp connection structures were observed in the hyphae of the fungus, which was grown on PDA medium for 4 days. On the basis of the mycological characteristics and pathogenicity of the fungus on the host plants, the causal agent was identified as Sclerotium rolfsii Saccardo. This is the first report of stem rot disease in garlic caused by S. rolfsii in Korea.
Agar
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Allyl Compounds
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Fungi
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Garlic
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Glucose
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Humans
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Hyphae
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Korea
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Soil
;
Solanum tuberosum
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Sulfides
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Triacetoneamine-N-Oxyl
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Vegetables
7.Soft Rot of Eggplant (Solanum melongena) Caused by Choanephora cucurbitarum in Korea.
Jin Hyeuk KWON ; Hyeong Jin JEE
Mycobiology 2005;33(3):163-165
In April 2002 and 2003, soft rot on fruit of eggplant (Solanum melongena) caused by Choanephora cucurbitarum was observed in the experimental fields at Gyeongnam Agricultural Research and Extension Services in Korea. The disease began with water-soaking and dark-green lesions, and then the infected tissues were rapidly rotten. Sporangium was subglobose in shape and sized 40~130 microm. Monosporous sporangiola were elliptic, fusiform or ovoid, brown in color, and measured as 12~20 x 6~14 microm. Sporangiospores having three or more appendages were elliptic, fusiform or ovoid in shape, dark brown or brown in color, and sized 14~20 x 7~16 microm. The fungus grew well on potato dextrose agar between 15 and 40degrees C and its optimum growth temperature was 30degrees C. Based on morphological characteristics, the causal fungus of the fruit soft rot of eggplant was identified as C. cucurbitarum. This is the first report on the soft rot of S. melongena caused by C. cucurbitarum in Korea.
Agar
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Fruit
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Fungi
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Glucose
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Korea*
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Solanum melongena*
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Solanum tuberosum
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Sporangia
8.Soft Rot of Tomato Caused by Mucor racemosus in Korea.
Jin Hyeuk KWON ; Seung Beom HONG
Mycobiology 2005;33(4):240-242
A soft rot of fruits caused by Mucor racemosus occurred on cherry tomato collected in Agricultural Products Wholesale Market in Jinju, Korea. The disease infection usually occurred wounded areas after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies were white to brownish to gray in color. Sporangia were 32~54 microm in size and globose in shape. Sporangiophores were 8~14 microm in width. Sporangiospores were 5~12 x 4~8 microm in size, ellipsoidal to subglobose in shape. Columella was 27~42 microm in size, obovoid, ellipsoidal, cylindrical-ellipsoidal, slightly pyriform in shape. Chlamydospores were numerous in sporangiophores and barrelshaped when young, subglobose in old cultures. Optimum growth temperature was about 25degrees C. The fungus was identified as M. racemosus Fres. This is the first report of soft rot on cherry tomato caused by M. racemosus in Korea.
Fruit
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Fungi
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Gyeongsangnam-do
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Korea*
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Lycopersicon esculentum*
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Mucor*
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Prunus
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Sporangia
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Water
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Wounds and Injuries
9.Leaf Spot of Cotton Rose Caused by Corynespora cassiicola in Korea.
Jin Hyeuk KWON ; Chang Seuk PARK
Mycobiology 2003;31(1):57-59
A leaf spot of cotton rose (Hibiscus mutabilis) occurred severely in the flower beds of cotton rose around Uiryeong-gun, Gyeongnam Province in Korea. The causal fungus was identified as Corynespora cassiicola on the basis of cultural and morphological characteristics of the fungus. The fungus grew well on potato dextrose agar and the colony color was gray to brown. Conidia were solitary or catenate, obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. They had 420 pseudosepta, and measured 35.2~173.6 x 8.8~19.9 microm. Conidia germinated as a bipolar type. Conidiophores were pale to mid brown in color, and measured 74.2~275.6 x 3.8~10.8 microm. Optimal temperature for mycelial growth was 30degrees C. The fungal isolate grown on PDA showed strong pathogenicity to cotton rose plant. This is the first report on the corynespora leaf spot of cotton rose (Hibiscus mutabilis) caused by Corynespora cassiicola in Korea.
Agar
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Flowers
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Fungi
;
Glucose
;
Korea*
;
Plants
;
Solanum tuberosum
;
Spores, Fungal
;
Virulence
10.Stem Rot of Tomato Caused by Sclerotium rolfsii in Korea.
Jin Hyeuk KWON ; Chang Seuk PARK
Mycobiology 2002;30(4):244-246
A destructive stem rot of tomato (Lycopersicon esculentum) occurred sporadically some farmers' fields in Jinju City, Gyeongnam province in Korea. The infected plants also showed stem, crown rot or whole plant blight. White mycelium spread over stems of infected plants and formed sclerotia on the old lesions nearby soil surface. The fungus showed maximum mycelial growth around 30degrees C. The fungus formed white colony on PDA, usually with many narrow mycelial strands in the aerial mycelium and the width were 4.0~9.8 microm. The typical clamp connections were formed on the mycelium. Numerous sclerotia was formed on PDA at 30degrees C. The shape of sclerotia was globoid and 1.0~3.0 mm in size. The fungus was isolated repeatedly from the infected tissues and the pathogenicity was confirmed to tomato and identified as Sclerotium rolfsii. This is the first report on the stem rot of tomato caused by S. rolfsii in Korea.
Crowns
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Fungi
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Gyeongsangnam-do
;
Korea*
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Lycopersicon esculentum*
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Mycelium
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Plants
;
Soil
;
Virulence