Curvularia sp. Jamur Patogen Baru Penyebab Penyakit Bercak Daun pada Tanaman Sawi

ABSTRACTCurvularia sp. a new fungal pathogen causing leaf spot on the leaf of mustard greenA new diseases symptom as small spots of 1.5 - 1 mm diameter has been found on mustard green's leaf of farmer's field at Tanjungsari Regency of Sumedang. This symptom is different from those previously known incited by Alternaria brassicae and A. brassicola, Pseudocercosporella capsellae as well as by Myscosphaerella brassicicola. Although the spots are small, they are abundant and accompanied with yellowing, making these symptoms detrimental to mustard green production which has to be green and healthy. A Koch Postulate has been performed and successfully identified that the fungal causal agent was of the genera of Curvularia. Previously, curvularia leaf spot disease has never been reported on mustard green in Indonesia.Keywords: Curvularia, Leaf spots, Mustard green, Brassica junceaABSTRAKGejala penyakit baru, berupa bercak hitam berukuran diameter 0,5 - 1 mm ditemukan pada daun tanaman sawi milik petani di daerah Tanjungsari Kabupaten Sumedang. Gejala demikian berbeda dengan gejala-gejala penyakit bercak yang selama ini dikenal disebabkan oleh Alternaria brassicae dan A. brassicola, Pseudocercosporella capsellae dan Myscosphaerella brassicicola. Walaupun gejalanya berukuran kecil, namun karena jumlahnya banyak dan menyebabkan daun menguning, menjadikan gejala penyakit ini merugikan tanaman sawi yang harus hijau dan sehat. Uji Postulat Koch telah dilaksanakan, dan berhasil mengidentifikasi bahwa berdasarkan morfologi mikroskopiknya, jamur tersebut adalah dari genus Curvularia. Penyakit bercak daun curvularia, sebelumnya, belum pernah dilaporkan terdapat pada tanaman sawi di Indonesia.Kata Kunci: Curvularia, Bercak daun, Sawi, Brassica juncea

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Identification Causes Leaf Spot Disease in Cempaka (Magnolia elegans (Blume.) H.Keng) Seedling and Its Control Techniques

Jurnal Wasian ◽

10.20886/jwas.v2i2.843 ◽

2015 ◽

Vol 2 (2) ◽

pp. 87

Author(s):

Arif Irawan ◽

Ilaa Anggraeni ◽

Margaretta Christita

Keyword(s):

Leaf Spot ◽

Fungal Pathogen ◽

Leaf Surface ◽

Control Technique ◽

Leaf Spot Disease ◽

Spot Disease ◽

Control Techniques ◽

Leaf Spots ◽

Early Signs ◽

Determination Key

This research purposes to identify the pathogen causing leaf spot in cempaka seedling and its control technique. Identify cause of disease is necessary to know precise technique control. Identification of disease was conducted in macroscopic appearances and microscopically to determine pathogens. Identification is done by using the determination key of fungi. The results showed that the early signs of leaf spot disease on cempaka seedlings in the nursery are streaks or spots on the leaf surface with distinct boundaries. Leaf spots are formed generally brown surrounded by darker boundaries. The result shows leaf spot disease on cempaka seedling was caused by fungal pathogen Colletotrichum sp. Techniques for controlling the disease can be done by isolating the infected seeds, reducing the intensity of canopy, and using the appropriate fungicides.

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Genera Jamur Patogen dan Persentase Penyakit Bercak Daun yang ditemukan pada Pertanaman Sawi Hijau (Brassica juncea) di Desa Serang, Kecamatan Karangreja, Purbalingga

BioEksakta : Jurnal Ilmiah Biologi Unsoed ◽

10.20884/1.bioe.2020.2.3.3387 ◽

2020 ◽

Vol 2 (3) ◽

pp. 392

Author(s):

Nia Sri Hartatik ◽

Eddy Tri Sucianto ◽

Endang Sri Purwati

Keyword(s):

Brassica Juncea ◽

Leaf Spot ◽

Survey Method ◽

Leaf Spot Disease ◽

Spot Disease ◽

Identification Of Fungi ◽

Micromorphological Characters ◽

Mustard Green ◽

Two Stages ◽

Colony Shape

Green mustard (Brassica juncea) is an annual or horticultural plant of the Brassica genus. The purpose of this research is to knowledge the type of fungi that cause leaf spot disease on green mustard plants and to know the large percentage of leaf spot diseases caused by fungus on mustard greens in Serang Village, Karangreja District, Purbalingga. This research is used survey method by taking purposive random sampling at two different locations. The type of fungus that causes leaf spot disease on (B. juncea) mustard green can be identified by isolating the part of plants are sick then identified. Identification of fungi is doing by two stages of observation, that is observation macromorphological characters and micromorphological characters. Observation of macromorphological characters includes colony color, colony shape, the edge of colony shape and colony reverse color. Observation of the micromorphology character includes the presence of hyphae, hyphae (insulated or non-insulated), conidia shape, conidia color, additional devices and conidiophores. The next stage to find out the type of fungus that causes leaf spot disease is Koch's Postulate.The results obtained there is one type of disease in green mustard plants. Leaf spot is one of the diseases of mustard greens caused by the fungus Alternaria sp, with a frequency of leaf spot disease as many as 196 times, and the percentage of disease of 51,30%.

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First Report of a Leaf Spot Disease of Bells-of-Ireland (Moluccella laevis) Caused by Cercospora apii in California

Plant Disease ◽

10.1094/pdis.2003.87.2.203a ◽

2003 ◽

Vol 87 (2) ◽

pp. 203-203

Author(s):

S. T. Koike ◽

S. A. Tjosvold ◽

J. Z. Groenewald ◽

P. W. Crous

Keyword(s):

Leaf Spot ◽

Sequence Data ◽

Disease Incidence ◽

Leaf Spot Disease ◽

Conidial Suspension ◽

Internal Transcribed Spacer Region ◽

First Report ◽

Spot Disease ◽

Leaf Spots ◽

Initial Symptoms

Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant that is field planted in coastal California (Santa Cruz County) for commercial cutflower production. In 2001, a new leaf spot disease was found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were surveyed during this time had at least 50% disease. Initial symptoms consisted of gray-green leaf spots. Spots were generally oval in shape, often delimited by the major leaf veins, and later turned tan. Lesions were apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported on leaves of M. laevis in Turkey (1). However, sequence data obtained from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and AY156919) indicated there were no base pair differences between the bells-of-Ireland isolates from California, our own reference isolates of C. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the plants in a dew chamber for 24 h, and maintaining them in a greenhouse (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots that were identical to those observed in the field. C. apii was again associated with all leaf spots. Control plants, which were treated with water, did not develop any symptoms. The test was repeated and the results were similar. To our knowledge this is the first report of C. apii as a pathogen of bells-of-Ireland in California. Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell University Press, Ithaca, New York, 1954.

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Development of specific culture media, studies on effect of media, pH and temperature on growth of Cercospora punicae, the causal agent of fruit and leaf spot disease of pomegranate

Journal of Pharmacognosy and Phytochemistry ◽

10.22271/phyto.2021.v10.i1l.13427 ◽

2021 ◽

Vol 10 (1) ◽

pp. 816-818

Author(s):

Mukesh . ◽

Sharma SK

Keyword(s):

Media Studies ◽

Leaf Spot ◽

Culture Media ◽

Causal Agent ◽

Leaf Spot Disease ◽

Spot Disease ◽

Specific Culture

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Lophomerum ponticum. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400790 ◽

1984 ◽

Author(s):

D. W. Minter

Keyword(s):

Great Britain ◽

Geographical Distribution ◽

Leaf Spot ◽

Causal Agent ◽

Leaf Spot Disease ◽

Spot Disease ◽

Green Leaves ◽

Rhododendron Ponticum

Abstract A description is provided for Lophomerum ponticum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Rhododendron ponticum. DISEASE: Leaf spot of rhododendron. In general Lophomerum ponticum appears to be saprophytic. Its ascocarps are usually not produced until the leaves have senesced, become detached and fallen to the litter. Occasionally, however, ascocarps can be found on browned regions of otherwise green leaves, and it seems possible, therefore, that the species is facultatively parasitic. It is important to distinguish this species from Lophodermium vagulum (CMI Descriptions 789) which is the causal agent of a leaf spot disease of chinese rhododendrons, but which does not occur on R. ponticum. GEOGRAPHICAL DISTRIBUTION: Europe (Great Britain), probably much more widespread. TRANSMISSION: By air-borne ascospores in wet or humid weather.

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Cercospora zeina is the causal agent of grey leaf spot disease of maize in southern Africa

European Journal of Plant Pathology ◽

10.1007/s10658-009-9443-1 ◽

2009 ◽

Vol 124 (4) ◽

pp. 577-583 ◽

Cited By ~ 26

Author(s):

Barbara Meisel ◽

Jeanne Korsman ◽

Frederik J. Kloppers ◽

Dave K. Berger

Keyword(s):

Southern Africa ◽

Leaf Spot ◽

Causal Agent ◽

Leaf Spot Disease ◽

Grey Leaf Spot ◽

Spot Disease ◽

Cercospora Zeina

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Characterization of Exserohilum rostratum, a new causal agent of banana leaf spot disease in China

Australasian Plant Pathology ◽

10.1007/s13313-011-0037-y ◽

2011 ◽

Vol 40 (3) ◽

pp. 246-259 ◽

Cited By ~ 11

Author(s):

Shan-Hai Lin ◽

Si-Liang Huang ◽

Qi-Qin Li ◽

Chun-Jin Hu ◽

Gang Fu ◽

...

Keyword(s):

Leaf Spot ◽

Causal Agent ◽

Leaf Spot Disease ◽

Spot Disease ◽

Exserohilum Rostratum ◽

Banana Leaf

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First Report of Leaf Smut of Gaillardia × grandiflora Caused by Entyloma gaillardianum in North America

Plant Health Progress ◽

10.1094/php-2010-0428-01-br ◽

2010 ◽

Vol 11 (1) ◽

pp. 51 ◽

Cited By ~ 3

Author(s):

Dean A. Glawe ◽

Tess Barlow ◽

Steven T. Koike

Keyword(s):

North America ◽

Leaf Spot ◽

Its Region ◽

Morphological Features ◽

Causal Agent ◽

Leaf Spot Disease ◽

First Report ◽

Spot Disease ◽

Leaf Smut

In the summer of 2009, a leaf spot disease occurred on 100% of Gaillardia × grandiflora cv. Goblin in a commercial nursery in coastal Monterey Co., CA. Nearly all of the affected plants were unsalable. The causal agent was determined to be Entyloma gaillardianum based on morphological features, host, and ITS region. This species has not been reported previously from this host in North America. Accepted for publication 16 March 2010. Published 28 April 2010.

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First Report of Leaf Spot Disease on Walnut Caused by Colletotrichum fioriniae in China

Plant Disease ◽

10.1094/pdis-09-14-0938-pdn ◽

2015 ◽

Vol 99 (2) ◽

pp. 289-289 ◽

Cited By ~ 9

Author(s):

Y. Z. Zhu ◽

W. J. Liao ◽

D. X. Zou ◽

Y. J. Wu ◽

Y. Zhou

Keyword(s):

Dna Sequences ◽

Leaf Spot ◽

Juglans Regia ◽

Morphological Characteristics ◽

Leaf Spot Disease ◽

Koch’S Postulates ◽

First Report ◽

Spot Disease ◽

Leaf Spots ◽

Koch's Postulates

In May 2014, a severe leaf spot disease was observed on walnut tree (Juglans regia L.) in Hechi, Guangxi, China. Leaf spots were circular to semicircular in shape, water-soaked, later becoming grayish white in the center with a dark brown margin and bordered by a tan halo. Necrotic lesions were approximately 3 to 4 mm in diameter. Diseased leaves were collected from 10 trees in each of five commercial orchards. The diseased leaves were cut into 5 × 5 mm slices, dipped in 75% ethanol for 30 s, washed three times in sterilized water, sterilized with 0.1% (w/v) HgCl2 for 3 min, and then rinsed five times with sterile distilled water. These slices were placed on potato dextrose agar (PDA), followed by incubating at 28°C for about 3 to 4 days. Fungal isolates were obtained from these diseased tissues, transferred onto PDA plates, and incubated at 28°C. These isolates produced gray aerial mycelium and then became pinkish gray with age. Moreover, the reverse of the colony was pink. The growth rate was 8.21 to 8.41 mm per day (average = 8.29 ± 0.11, n = 3) at 28°C. The colonies produced pale orange conidial masses and were fusiform with acute ends, hyaline, sometimes guttulate, 4.02 to 5.25 × 13.71 to 15.72 μm (average = 4.56 ± 0.31 × 14.87 ± 1.14 μm, n = 25). The morphological characteristics and measurements of this fungal isolate matched the previous descriptions of Colletotrichum fioriniae (Marcelino & Gouli) R.G. Shivas & Y.P. Tan (2). Meanwhile, these characterizations were further confirmed by analysis of the partial sequence of five genes: the internal transcribed spacer (ITS) of the ribosomal DNA, beta-tubulin (β-tub) gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene, chitin synthase 3(CHS-1) gene, and actin (ACT) gene, with universal primers ITS4/ITS5, T1/βt2b, GDF1/GDR1, CHS1-79F/CHS1-354R, and ACT-512F/ACT-783R, respectively (1). BLAST of these DNA sequences using the nucleotide database of GenBank showed a high identify (ITS, 99%; β-tub, 99%; GAPDH, 99%; CHS-1, 99%; and ACT, 100%) with the previously deposited sequences of C. fioriniae (ITS, KF278459.1, NR111747.1; β-tub, AB744079.1, AB690809.1; GAPDH, KF944355.1, KF944354.1; CHS-1, JQ948987.1, JQ949005.1; and ACT, JQ949625.1, JQ949626.1). Koch's postulates were fulfilled by inoculating six healthy 1-year-old walnut trees in July 2014 with maximum and minimum temperatures of 33 and 26°C. The 6-mm mycelial plug, which was cut from the margin of a 5-day-old colony of the fungus on PDA, was placed onto each pin-wounded leaf, ensuring good contact between the mycelium and the wound. Non-colonized PDA plugs were placed onto pin-wounds as negative controls. Following inoculation, both inoculated and control plants were covered with plastic bags. Leaf spots, similar to those on naturally infected plants, were observed on the leaves inoculated with C. fioriniae within 5 days. No symptoms were observed on the negative control leaves. Finally, C. fioriniae was re-isolated from symptomatic leaves; in contrast, no fungus was isolated from the control, which confirmed Koch's postulates. To our knowledge, this is the first report of leaf disease on walnut caused by C. fioriniae. References: (1) L. Cai et al. Fungal Divers. 39:183, 2009. (2) R. G. Shivas and Y. P. Tan. Fungal Divers. 39:111, 2009.

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