scholarly journals Effect of environmental factors on toxin production of Drechslera bicolor, a causal agent of leaf blight in bell pepper

2015 ◽  
Vol 9 (8) ◽  
pp. 521-526
Author(s):  
S Jadon K ◽  
Shah R ◽  
N Gour H ◽  
Sharma Pankaj
Keyword(s):  
Environmental Factors ◽  
Toxin Production ◽  
Leaf Blight ◽  
Causal Agent ◽  
Bell Pepper

scholarly journals Draft Genome Sequence of Cercospora cf. sigesbeckiae, a Causal Agent of Cercospora Leaf Blight on Soybean

2017 ◽  
Vol 5 (36) ◽  
Author(s):  
Sebastian Albu ◽  
Sandeep Sharma ◽  
Burton H. Bluhm ◽  
Paul P. Price ◽  
Raymond W. Schneider ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Fungal Pathogen ◽  
Draft Genome ◽  
Leaf Blight ◽  
Causal Agent ◽  
Draft Genome Sequence ◽  
Agricultural Commodities

ABSTRACT Cercospora cf. sigesbeckiae is an ascomycete fungal pathogen that infects various plants, including important agricultural commodities, such as soybean. Here, we report the first draft genome sequence and assembly of this pathogen.

scholarly journals Redroot pigweed as a host for Alternaria alternata – the causal agent of Alternaria leaf blight in potato

2015 ◽  
Vol 102 (1) ◽  
pp. 115-118 ◽  
Author(s):  
Stanisław Mazur ◽  
Halina Kurzawińska ◽  
Małgorzata Nadziakiewicz ◽  
Jacek Nawrocki
Keyword(s):  
Alternaria Alternata ◽  
Leaf Blight ◽  
Causal Agent ◽  
Redroot Pigweed ◽  
Alternaria Leaf Blight

Environmental factors associated with a toxic bloom of Microcystis aeruginosa

2000 ◽  
Vol 57 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Jean M Jacoby ◽  
Diane C Collier ◽  
Eugene B Welch ◽  
F Joan Hardy ◽  
Michele Crayton
Keyword(s):  
Environmental Factors ◽  
Microcystis Aeruginosa ◽  
Toxin Production ◽  
Water Transparency ◽  
Cyanobacterial Blooms ◽  
Zooplankton Abundance ◽  
Factors Associated ◽  
Water Column Stability ◽  
Microcystin Concentration ◽  
Toxic Bloom

Environmental factors associated with the occurrence of toxic cyanobacterial blooms and toxin production were investigated during the summers of 1994 and 1995 in Steilacoom Lake, Washington. A pronounced and prolonged toxic bloom of Microcystis aeruginosa occurred during summer 1994 but not during 1995. Lake characteristics that were associated with the toxic bloom in 1994 were higher total phosphorus, decreased water transparency, high water column stability, high surface water temperature and pH, and decreased lake flushing. Decreased water transparency during 1994 may have been due to significantly lower zooplankton abundance. We hypothesize that this decreased transparency was caused by increased planktivory by higher numbers of coho salmon (Oncorhynchus kisutch) fingerlings during 1994 and (or) inhibition of zooplankton grazing by Microcystis. The success of Microcystis over other cyanobacteria was associated with low nitrogen to phosphorus ratios and low nitrate-nitrogen with sufficient ammonium-nitrogen concentrations. Toxin production (i.e., micrograms of microcystin per gram of plankton biomass) was not constant over the duration of detectable toxicity; hence, no relationship was found between Microcystis abundance and microcystin concentration. However, microcystin concentration was positively correlated with increasing soluble reactive phosphorus concentrations between 1 and 10 µg·L-1, indicating that toxin production may have been limited by phosphorus.

Environmental factors affecting the cracking of greenhouse-grown bell pepper fruit

1999 ◽  
Vol 74 (1) ◽  
pp. 6-12 ◽  
Author(s):  
S. Moreshet ◽  
C. Yao ◽  
B. Aloni ◽  
L. Karni ◽  
M. Fuchs ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Bell Pepper ◽  
Factors Affecting ◽  
Pepper Fruit

scholarly journals First Report of Pestalotiopsis microspora Causing Leaf Blight of Reineckea carnea in Central China

Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 667-667 ◽  
Author(s):  
M. D. Wu ◽  
G. Q. Li ◽  
D. H. Jiang
Keyword(s):  
Basal Cell ◽  
Apical Cell ◽  
Morphological Characteristics ◽  
Leaf Blight ◽  
Causal Agent ◽  
Central China ◽  
Fluorescent Light ◽  
Leaf Margin ◽  
First Report ◽  
Pestalotiopsis Microspora

Pink reineckia (Reineckea carnea (Andrews) Kunth) is an evergreen herbaceous perennial plant widely grown as groundcover or for medical purposes in southern China. In 2006 and 2007, severe leaf blight was observed on pink reineckia in Wuhan, China. On newly formed pink reineckia leaves, symptoms were first noted in early May as grayish to dark brown, oval or irregular-shaped lesions, 1.5 to 0.2 × 0.5 to 0.1 cm (n = 50), on the leaf margin or leaf tip. A yellowish halo surrounded each lesion. Lesions enlarged and coalesced and diseased leaves became blighted during the fall and winter. In severely infected plots, most plants became straw-colored and had to be replaced with healthy seedlings. A fungus was isolated from surface-disinfested lesions on potato dextrose agar (PDA) at a frequency of 85.7%. One of 30 isolates, designated C2, was characterized further. The fungus growing on PDA at 20°C for 14 days formed zonate white colonies and black acervular conidiomata. Conidia of the fungus aggregated on acervuli as droplets. Conidia were fusiform and 20.7 to 32.2 × 5.8 to 9.8 μm (n = 50). Each conidium had one hyaline apical cell, one hyaline basal cell, and three dark brown median cells. There were two to four hyaline filamentous appendages 8.1 to 20.4 μm long attached to each apical cell and one hyaline appendage 2.4 to 7.1 μm long attached to each basal cell. The cultural and morphological characteristics of isolate C2 matched the description for Pestalotiopsis microspora (Speg.) Batista & Peres (1,2). The internal transcribed spacer (ITS) region of the ribosomal DNA (ITS1-5.8S-ITS2) was PCR-amplified and sequenced. The ITS sequence (606 bp) for isolate C2 (GenBank Accession No. EU935587) was 100% similar to P. microspora isolates TA-57 (GenBank Accession No. AY924267) and LK32 (GenBank Accession No. DQ001002). Pathogenicity of isolate C2 was tested with the method described by Keith et al. (2). Four detached leaves were wound inoculated or inoculated without wounding with mycelia on agar plugs (4 mm in diameter; three plugs per leaf) or conidial suspensions (107 conidia per ml; 20 μl on each of three sites per leaf). Control leaves were wound inoculated with PDA or sterile water. All inoculated leaves were maintained in a moist enamel tray under fluorescent light for 7 days at 20°C. The test was performed twice. After 4 days of incubation, necrotic leaf lesions resembling symptoms that occurred in the field were observed on the wound-inoculated leaves, whereas the control leaves and C2-inoculated leaves without wounding remained healthy. Therefore, wounding was necessary for symptom development (2). A fungus was reisolated from the C2-induced leaf lesions and the morphology of colonies and conidia were identical to that for isolate C2 of P. microspora. On the basis of the results of isolations, inoculations, and fungal identification, P. microspora was determined to be the causal agent for leaf blight of pink reineckia occurring in Wuhan, China. This fungus previously has been reported as the causal agent of scab disease of Psidium guajava in Hawaii (2), decline of Torreya taxifolia in Florida (3), and leaf blight of Lindera obtusiloba in Korea (1). To our knowledge, this is the first report of the occurrence of P. microspora on R. carnea. References: (1) Y. H. Jeon et al. Plant Pathol. 56:349, 2007. (2) L. M. Keith et al. Plant Dis. 90:16, 2006. (3) M. W. Schwartz et al. Plant Dis. 80:600, 1996.

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