• The Plant Pathology Journal
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• 제19권6호
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• pp.274-279
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• 2003

Two Gymnosporangium species, G. japonicum and G. cornutum, causing cedar-apple rust, were newly identified in Korea, and a new aecial host for each fungus was found by artificial inoculation. Detailed descriptions of the species were made based on macroscopic features (symptoms and signs) and light and scanning electron microscopic observations of spores and peridial cells. G. japonicum from Juniperus chinensis var. horizontalis had Photinia villosa as its new aecial host G. cornutum from J. rigida showed its aecial stage on Sorbus alnifolia.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.133.2-134
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• 2003

Cedar-apple rust fungi had been collected at 36 sites throughout the country from 1984 to 2001 and deposited at the Herbarium of Korea Forest Research Institute (HKFRI). We conducted the morphological examination on the dried specimens by light and scanning electron microscopy and as results six Gymnosporangium species were identified. Three species, G. asiaticum, G. clavaritforme and G. yamadae, were previously described in Korea, while the other three species, G. cornutum, G. globosum, and G. japonicum were new to Korea. Here we present the detailed morphological descriptions, distribution, host ranges and keys to species in both aecial and telial stages of each species. Some morphological characteristics related with telial formation on trees were newly identified; witches brooms for G. asiaticum, small galls for G. yamadae and telial formations on trunk for G. japonicun Geographically G. asiaticum and G. yamadae distributed widely throughout Korea, while the others were collected only at the limited locations. Eight Juniperus species as telial hosts and fifteen Rosaceous plants as aecial hosts were confirmed to be new in Korea.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.324-330
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• 2021

Agriculture is one of the essential needs of human life on planet Earth. It is the source of food and earnings for many individuals around the world. The economy of many countries is associated with the agriculture sector. Lots of diseases exist that attack various fruits and crops. Apple Tree Leaves also suffer different types of pathological conditions that affect their production. These pathological conditions include apple scab, cedar apple rust, or multiple diseases, etc. In this paper, an automatic detection framework based on deep learning is investigated for apple leaves disease classification. Different pre-trained models, VGG16, ResNetV2, InceptionV3, and MobileNetV2, are considered for transfer learning. A combination of parameters like learning rate, batch size, and optimizer is analyzed, and the best combination of ResNetV2 with Adam optimizer provided the best classification accuracy of 94%.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.134.1-134
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• 2003

Aecial host ranges of four Gymnosporangium species causing cedar-apple rust diseases, G. asiaticum, G. cornutum, 5. japonicum and G. yamadae, were investigated through artificial inoculation. Thirteen species of nine genera among Rosaceous plants, which have been reported as social hosts in Korea, were inoculated with fresh teliospores spores in early days of May of 2000 and of 2001, respectively. In the results, we re-confirmed that there was highly specific relationship between the rust species and aecial hosts and report new aecial hosts of four Gymnosporangium species. Teliospores of G. cornutum collected from Juniperus rigida successively produced spermogonia and aecia only on Sorbus alntifolia, the first report on host alteration of G. cornutum in Korea. Positive responses by teliospores of G. japonicum from J. chinenis of Suwon and from J. chinenis var. horizontalis of Jeju island were obtained only on P. villosa. Crataegus pinnatifida was confirmed as a new aecial host of G. viatium. Until this time, G. ymadae was believed to have Malus as the aecial host. However, teliospores of G. yamadae collected from J. chinensis var. kaizuka successively formed spermogonia and aecia on the leaves of Chaenomeles lagenaria, C. sinensis, Pyrus pyrtifolia var, culta, P. ussuriensis, Malus pumila and M. sileboldii. The date for maturation of spermogonia and aecia, and symptom development varied according to the rust fungi and aecial host plants, respectively.

• 식물병연구
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• 제24권4호
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• pp.249-256
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• 2018

1992년부터 2010년까지 경북 군위를 비롯한 사과 주산지 8개 지역에서 사과의 잎에 발병하는 병의 발생상황을 조사하였다. 사과의 잎에 발병하는 주요 병은 붉은별무늬병, 잿빛곰팡이병, 점무늬낙엽병, 갈색무늬병이였다. 지난 19년간 사과 잎에 발병하는 병의 발생양상은 상당히 많이 변해왔는데, 1990년대 초반, 발생이 많아 문제가 되었던 붉은별무늬병, 검은별무늬병은 1990년대 후반 이후 발생이 감소하거나 발생하지 않았다. 잿빛곰팡이병은 일부 과원에 따라 발병이 관찰되었으며, 점무늬낙엽병과 갈색무늬병의 발병은 지속적으로 발병이 관찰되었다. 병해발생상황은 기상조건, 재배조건 및 방식, 약제 살포 체계 등 다양한 요인에 의해 변화한 것으로 판단된다. 이러한 병해들의 발생상황의 변화에 대한 조사는 장기적이고 지속적인 모니터링이 필요할 것으로 판단된다.

• The Plant Pathology Journal
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• 제21권4호
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• pp.310-316
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• 2005

The objectives of this study were to identify the aecial host ranges of four Korean Gymnosporangium species, G. asiaticum, G. cornutum, Gjaponicum and Gyamadae, and to verify the morphological characteristics of telia as diagnostic keys to the species. Thirteen Korean Rosaceous woody species were artificially inoculated with teliospores obtained from Juniperus species. There was high specificity between telial and aecial hosts and the fungal species, providing the first experimental proof on host alternation of these rust fungi in Korea. Telia on the witches' broom and on the small galls were identified as new telial characteristics in G asiaticum and in G. yamadae, respectively. Aecial hosts of G. asiaticum and G. yamadae showed varying responses in their susceptibility and in the days required for formation and duration of spermogonia and aecia after inoculation. Four telial host species in Juniperus were confirmed for the first time in Korea, which include J. chinensis var. kaizuka, J. chinensis var. horizontalis and J. chinensis var. globosa for G. asiaticum; and J. chinensis var. kaizuka for G. yamadae.