• The Plant Pathology Journal
• /
• 제15권1호
• /
• pp.76-78
• /
• 1999

A Phloeospora leaf spot disease on Spiraea prunifolia var. simpliciflora was noticed to commonly occur in Korea. The causal organism of the disease was identified as Phloeospora spiraeicola based on the morphological characteristics of conidiomata and conidia. Pathogenicity of the fungus was proved by artificial inoculation. This is the first record of Phloeospora leaf spot in Korea.

• 농약과학회지
• /
• 제6권2호
• /
• pp.87-95
• /
• 2002

야외에서 채집한 27종 식물의 메탄올 추출물의 벼 도열병, 벼 잎집무늬마름병, 토마토 잿빛곰팡이병, 토마토 역병, 밀 녹병 및 보리 흰가루병에 대한 방제효과를 실험하였다. 벼 도열병에 대하여는 환삼덩굴, 비비추, 맥문동, 황기 추출물이, 잿빛곰팡이병에 대해서는 닭의장풀 추출물이, 보리 흰가루병에 대하여는 황기 추출물이 그리고 밀 녹병에 대하여는 비비추, 맥문동, 까마중 그리고 황기 추출물이 우수한 방제효과를 보였다. 이들 중 밀 녹병에 대하여 방제효과가 우수한 4종 시료를 선발하여 이들의 방제 특성을 조사하였나. 맥문동과 까마중 추출물은 밀 녹병에 대한 예방효과가 다른 추출물에 비하여 우수하였으며, 치료효과는 황기 추출물은 우수하였으나 까마중 추출물은 다소 미약한 치료활성이 있었다. 식물 추출물의 침투이행성은 엽육이행과 엽간이행으로 실험하였는데, 4종 추출물 모두 엽간이행은 거의 없었으나, 엽육이행은 우수하였다. 식물추출물의 약효지속성은 대부분 좋았으며 특히 비비추와 까마중 추출물은 약제처리 7일 후에도 95% 이상의 방제가를 보였다. 이들 결과를 종합해 보면 4종 식물 추출물 특히 까마중 추출물은 포장에서 밀 녹병에 대하여 우수한 방제효과를 보이리라 생각된다.

• The Plant Pathology Journal
• /
• 제28권2호
• /
• pp.212-215
• /
• 2012

Pyrenophora graminea, the causal agent of leaf stripe disease, is an economically important pathogen of barley found worldwide. It is critical to clearly define and standardize the leaf stripe assessment methods to avoid subjectivity and variability between assessors. Therefore, in this study, a comparison between the proportion of diseased plants (DP) and the proportion of diseased leaves (DL) per plant was investigated. Disease assessments were made visually at multiple sample sites in artificially and naturally inoculated research and production fields during four growing seasons. There were significant differences (P = 0.001) among cultivars in mean DP and DL averages, which are consistently higher in susceptible barley. However, DP values increased linearly as DL increased. The slopes and intercepts of the DP-DL relationship were consistent over the four growing seasons. This result might make a significant contribution for leaf stripe assessment in barley breeding programme.

• 원예과학기술지
• /
• 제30권2호
• /
• pp.137-143
• /
• 2012

Chinese cabbage plant was grown hydroponically for 4 weeks in order to examine the temporal relationship of calcium concentration of the nutrient solution with calcium content in the leaf tissue and susceptibility of the tissue to soft rot disease by $Pectobacterium$ $carotovorum$ ssp. $carotovorum$ (Pcc). Calcium concentration from 0.5 to 32.0 mM was maintained for 1 week using Hoagland & Arnon solution. The calcium content of the leaf was proportionally increased to the concentration of the nutrient in the solution (r = 0.912). In contrast, the severity of soft rot symptom in the young leaves was inversely related with the amount of calcium supplied to the nutrient solution (r = 0.899). Water-soluble chitosan, prepared by hollow fiber filtration (> 100 kDa) was applied into the nutrient solution from 0.0 to 5,000 ppm. The chitosan of 10 ppm was the most effective to promote calcium uptake of the leaf, showing 155% of the control. The same chitosan solution prohibited most soft rot development of the leaf by Pcc, exhibiting only 53% of the control. Among different molecular weight fractions, chitosan fraction obtained from 30-100 kDa molecular weight cut-off promoted calcium uptake the most up to 163% of the control, and reduced the development of soft rot disease recording merely 36% of the control of the leaf tissue. The results obtained in the present study suggest that large scale production of water-soluble chitosan with an optimum molecular weight and its commercial application to Chinese cabbage production will be important to improve yield and quality of the crop.

• The Plant Pathology Journal
• /
• 제25권4호
• /
• pp.328-332
• /
• 2009

Diseases caused by Pepper yellow leaf curl virus infection is considered to be emerging plant diseases in Indonesia in the last five years. One key factor for disease management is the availability of accurate detection of the virus in plants. Polyclonal antibody for Pepper yellow leaf curl Indonesia virus-Bogor (PYLCIV-Bgr) was produced for detection of the virus using I-ELISA and DIBA methods. The antibody was able to detect PYLCIV-Bgr from infected plants up to dilution 1/16,384 and cross reaction was not observed with Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV), and Chilli veinal mottle virus (ChiVMV). Positive reaction was readily detected in membrane containing Begomovirus samples from Yogyakarta (Kaliurang and Kulonprogo) and West Java (Bogor and Segunung). Infection of PYLCIV-Bgr in chillipepper, tomato, and Ageratum conyzoides was also confirmed using polyclonal antibody for PYLCIV-Bgr in DIBA. Polyclonal antibody for PYLCIV-Bgr is suggested to be included in disease management approach due to its good detection level.

• 한국식물병리학회지
• /
• 제11권3호
• /
• pp.224-229
• /
• 1995

Occurrence and incidences of major diseases of peach (Prunus persicae pv. vulgaris), leaf curl caused by Taphrina deformans, bacterial shot hole caused by Xanthomonas campestris pv. pruni, brown rot caused by Monilinia fructicola, and anthracnose caused by Glomerella cingulata in peach orchards in Cheongdo and Kyungsan areas of Gyeongbuk province, Korea, were investigated for four years from 1990 to 1993. In leaf curl and bacterial shot hole which mainly occurred on leaves, frist disease occurrences were dated from late April to early May. The maximum leaf curl incidence was dated in mid May, while dates of the maximum bacterial shot hole incidence varied from mid May to mid August depending on the years surveyed. In brown rot and anthracnose on fruit, the first disease occurrence dates ranged from early June to early August; however, the maximum disease incidences for both were invariably dated in late August. The disease incidences on the dates of the maximum incidences differed year by year, and the averages for the 4 years were 13.2%, 10.5%, 10.9% and 3.8% for leaf curl, bacterial shot hole, brown rot and anthracnose, respectively. Especially in the leaf curl disease, the first disease occurrence dates and the maximum disease incidences matched with the amounts of precipitation of rain up to April, suggesting that the disease occurrence may be related to the precipitation during the early season. The occurrence of leaf curl was somewhat higher in cultivar“Baekmi”than other cultivars. All of the major disease occurred more in hilly orchards than in plain ones.

• 농업생명과학연구
• /
• 제50권4호
• /
• pp.249-253
• /
• 2016

Aster glehni Franchet et Schmidt is a compositae plant and has been known as a native specie in Ulleung Island, Korea. It is officially recognized as a regional specialty that grows only in this region. In 2014, brown and dark spots were observed on aster leaves in a forest research field, Jinju, Korea. A causal agent was isolated from the disease symptomatic leaves and identified as fungus Alternaria solani. Fungal morphological characteristics and molecular identification with internal transcribed spacer sequences were synchronized as A. solani. The isolated fungi reproduced the same disease symptoms when the fungus was artificially inoculated on healthy aster leaves. This is the first report that A. solani caused leaf blight disease in Aster glehni in Korea.

• The Plant Pathology Journal
• /
• 제19권4호
• /
• pp.189-194
• /
• 2003

The effects of prochloraz on membrane permeability and germination of uredospores of Puccinia recondita were investigated to determine its potential mode of action on wheat leaf rust control activity. Disease control activity of ergosterol biosynthesis inhibitors (EBIs) and their activities on uredospore membrane permeability and germination were examined with wheat leaf rust pathogen, both in vitro and in vivo. While wheat leaf rust was not controlled by prochloraz, electrolytic leakage and spore germination of P. recondita uredospore was the highest with the use of prochloraz among the eight fungicides tested. Prochloraz stimulated uredospore of P. recondita to germinate at a higher ratio. Although certain EBIs, such as hexaconazole, showed excellent control activity, their effects on uredospore membrane permeability and germination was much inferior to prochloraz. Therefore, results of this study suggest that effects of EBIs on membrane permeability and germination of uredospore are not always correlated with their disease control activity.

• 한국식물병리학회지
• /
• 제11권3호
• /
• pp.217-223
• /
• 1995

Nature of graft transmissibility of pear abnormal leaf spot disease was examined by various grafting methods in the greenhouse and field. When the diseased and symptomless twigs were collected in winter and grafted in the next spring to the seed-originated healthy root stock, the abnormal leaf spot was developed only in the case of the diseased twigs. Double grafting on a seed-originated healthy root stock, where the diseased and the symptomless twigs were used as 1st and 2nd scions, respectively, developed abnormal leaf spot lesions without exception on the 2nd scions. Tongue-graft with the diseased and the symptomless trees also incited abnormal leaf spots on the both trees. Abnormal leaf spots of were also developed on HN-39, an indicator pear tree, used as a 2nd scion in a double graft test, where the diseased twig and a seed-originated healthy tree were used as the 1st scion and the root stock, respectively. When the diseased twig was top-grafted to the healthy root stock, lesion development of abnormal spot was limited to the grafted twig itself in the 1st year, but expanded to the main branches in the 2nd year, and spread over the whole tree in the 3rd year. This result indicates that the causal agent of abnormal leaf spot disease is transmitted by graft.

• Mycobiology
• /
• 제46권2호
• /
• pp.168-171
• /
• 2018

In 2016, a severe leaf spot disease was found on Iris ensata Thumb. in Nanjing, China. The symptom was elliptical, fusiform, or irregularly necrotic lesion surrounded by a yellow halo, from which a small-spored Alternaria species was isolated. The fungus was identified as Alternaria iridiaustralis based on morphological characteristics. The pathogenicity tests revealed that the fungus was the causal pathogen of the disease. Phylogenic analyses using sequences of ITS, gpd, endoPG, and RPB2 genes confirmed the morphological identification. This study is the first report of A. iridiaustralis causing leaf spots on I. ensata in China.