PHOMOPSIS BLACK ROT OF CUCURBITS

1957 ◽  
Vol 35 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Colin D. McKeen
Keyword(s):  
New Species ◽  
Stem Canker ◽  
Causal Agent ◽  
Black Rot ◽  
Mycosphaerella Melonis ◽  
Rot Disease ◽  
A New Species

A new species, Phomopsis cucurbitae, is described as the chief causal agent of a black rot disease of greenhouse cucumbers in Ontario. In addition to causing stem canker, the fungus occasionally causes decay of fruits. Similarities in macroscopic symptoms caused by P. cucurbitae and by another fungus, Mycosphaerella melonis, that also causes black rot of cucurbits, are pointed out. The pathogenicity of P. cucurbitae on cucurbits and tomato is discussed.

scholarly journals A new species of micro-organism (Proteus melanovogenes) causing black rot in eggs

1937 ◽  
Vol 37 (1) ◽  
pp. 79-97 ◽  
Author(s):  
A. A. Miles ◽  
E. T. Halnan
Keyword(s):  
New Species ◽  
Black Rot ◽  
Egg Shells ◽  
A New Species

1. An organism is described as a specific cause of black rot in two consignments of hens' eggs imported into England.2. It produces the rot experimentally when inoculated into fresh eggs, and penetrates apparently normal egg shells.3. Four hens inoculated with the organisms laid eggs that failed to develop the specific rot. The number of hens used was small, and no definite conclusion about the mode of infection can be drawn from the result of this experiment.4. The organism is found in English soils and manures.5. Eleven of 100 English hen sera agglutinated the organism in dilutions of 1 in 80 to 1 in 320.6. The organism is provisionally placed in theProteusgroup, and the nameProteus melanovogenesis assigned to it.

scholarly journals Phomopsis pisi – a new species causing pea stem canker

2010 ◽  
Vol 42 (No. 3) ◽  
pp. 95-98
Author(s):  
M. Ondřej ◽  
L. Odstrčilová ◽  
R. Dostálová
Keyword(s):  
Czech Republic ◽  
New Species ◽  
Pisum Sativum ◽  
Stem Canker ◽  
Anamorphic Fungi ◽  
Maturity Stage ◽  
A New Species

The new species <i>Phomopsis pisi</i> Ondřej sp. n. (Anamorphic Fungi – Coelomycetes) occurred on stems of pea (<i>Pisum sativum</i> L.) cv. Adept at Šumperk-Temenice (Czech Republic). The fungus caused plants to die at the green maturity stage. The new species differs from Phomopsis pisicola. It differs in the length and width of conidiophores and conidia.

scholarly journals First report of brown rot of nectarine caused by Monilia yunnanensis in Tibet

Plant Disease ◽  
2021 ◽  
Author(s):  
Shuwu Zhang ◽  
Dong Xiang ◽  
Tong Li ◽  
Bingliang Xu
Keyword(s):  
New Species ◽  
Phylogenetic Trees ◽  
Prunus Persica ◽  
Brown Rot ◽  
Fruit Production ◽  
Economic Losses ◽  
Morphological Identification ◽  
First Report ◽  
Rot Disease ◽  
A New Species

Brown rot caused by Monilinia spp. is one of the most important diseases of stone fruits. To date, three species of Monilinia have been found to occur on Prunus species worldwide: Monilinia fructicola (G. Winter) Honey, Monilinia fructigena (Aderhold & Ruhland) Honey, and Monilinia laxa (Aderhold & Ruhland) Honey (Zhu et al. 2005; Hu et al. 2011a). While M. fructicola is widespread in the Americas, and parts of Europe and Asia (CABI, 2010), M. laxa and M. fructigena are the primary species causing brown rot of peach in Europe (Bryde et al. 1977). In China, a new species Monilia yunnanensis was identified in 2011 (Hu et al. 2011b; Zhao et al. 2013; Yin et al. 2015; Yin et al. 2017). However, the species causing brown rot of nectarine (Prunus persica var. nectarina) in Tibet have not been undertaken. In the summer of 2017-2018, brown rot disease of nectarine was observed in Nyingchi, Tibet, and approximately 30% of nectarines were affected annually. Therefore, the brown rot disease of nectarine is one of the main factors that restrict the yield and quality of nectarine fruit production, and causes severe economic losses in Tibet. Thirty-six nectarine fruit with typical brown rot symptoms were collected from Tibet during the summer of 2017-2018. In order to isolate the causal agent, small pieces of pericarp were disinfected with 75% ethanol for 1 min, and then for 1 min in 1% NaOCl, rinsed in sterile distilled water for three times, dried on sterile paper and placed on potato dextrose agar (PDA). Thirty-six single-spore isolates were obtained and all morphologically similar, and three representative isolates 2-1, 2-16 and 2-31 which were from different period and years in 2017-2018 were characterized phylogenetically and morphologically to identify them to species level. Pathogenicity of each representative isolate was confirmed by inoculating five surface-disinfected mature nectarines with mycelial plugs in the wound of the fruit. Nectarine fruit inoculated with sterile PDA plugs served as the negative control. The inoculated nectarines developed brown lesions after 6 days incubation at 22°C, and the pathogen was successfully re-isolated. There were no symptoms on the control nectarine fruit. The isolates 2-1, 2-16 and 2-31 produced gray-green colonies with even margins and concentric rings of sporogenous mycelium after 3 days incubation, and abundant black-colored stromata on the media after 16 days of incubation at 22°C, resembling those described for M. yunnanensis (Hu et al. 2011b). Conidia were one-celled, hyaline, ellipsoid to lemon shape (9.24 to 15.58 μm), and borne in branched monilioid chains. The average daily growth of mycelium on PDA at 22°C was 11.56 mm. Therefore, the isolates 2-1, 2-16 and 2-31 were preliminarily identified as M. yunnanensis based on the morphological investigations (Hu et al. 2011b). Morphological identification was confirmed by phylogenetic analysis based on sequences of glyceraldehyde-3-phosphate dehydrogenase (G3PDH) and β-tubulin (TUB2) genes of 2-1, 2-16 and 2-31 which were amplified using primers Mon-G3pdhF/Mon-G3pdhR and Mon-TubF1/Mon-TubR1 (Hu et al. 2011b). In both G3PDH and TUB2 phylogenetic trees, the isolates 2-1, 2-16 and 2-31 formed monophyletic clades within a derived clade with the M. yunnanensis isolates. Additionally, the three isolates were more closely related to M. yunnanensis (HQ908782.1 and HQ908783.1) than to other Monilinia species. Based on morphological and molecular identification, the isolates 2-1, 2-16 and 2-31 were identified as M. yunnanensis. Previously, M. yunnanensis has been reported as a new species causing brown rot of peach in China (Hu et al, 2011b). To our knowledge, this is the first report of M. yunnanensis causing nectarine fruit brown rot in Tibet. These findings suggest that M. yunnanensis is spreading on its principal host plants and causing substantial economic losses in the Tibet fruit production.

Pathovar specific molecular detection of Xanthomonas campestris pv. campestris, the causal agent of black rot disease in cabbage

2019 ◽  
Vol 41 (3) ◽  
pp. 318-328 ◽  
Author(s):  
Mehede H. Rubel ◽  
Sathishkumar Natarajan ◽  
Mohammad R. Hossain ◽  
Ujjal K. Nath ◽  
Khandker S. Afrin ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Molecular Detection ◽  
Causal Agent ◽  
Black Rot ◽  
Rot Disease ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals Detection of Soilborne Alternaria radicina and Its Occurrence in California Carrot Fields

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 891-895 ◽  
Author(s):  
B. M. Pryor ◽  
R. M. Davis ◽  
R. L. Gilbertson
Keyword(s):  
Selective Medium ◽  
Causal Agent ◽  
Black Rot ◽  
Field Soil ◽  
Positive Correlation ◽  
Organic Debris ◽  
Selective Agar ◽  
Infested Field ◽  
Dry Soil ◽  
Rot Disease

Alternaria radicina, causal agent of black rot disease of carrot, was recovered from soil by plating dilutions on a semi-selective medium, A. radicina semi-selective agar. The efficiency of this soil assay was 93% based on recovery of the fungus from non-infested field soil amended with A. radicina conidia. Soilborne A. radicina was recovered from five of six carrot-growing areas in California, but was only commonly found in the Cuyama Valley, where the fungus was detected in 83% of sampled fields. Over a 3-year period of sampling, A. radicina soil populations in Cuyama Valley fields prior to carrot planting ranged from 0 to 317 CFU/g. There was a positive correlation between A. radicina soil populations in these fields and the incidence of black rot disease at harvest. A. radicina was recovered from dry soil after 4 years of storage, and the fungus survived in this soil as solitary conidia or as conidia associated with organic debris.

Identification and Characterization of Sphaerulina vaccinii as the Cause of Leaf Spot and Stem Canker in Lowbush Blueberry and its Epidemiology

2021 ◽  
Author(s):  
Shawkat Ali ◽  
Paul D. Hildebrand ◽  
Willy E. Renderos ◽  
Pervaiz Akbar Abbasi
Keyword(s):  
New Species ◽  
Leaf Spot ◽  
Phylogenetic Analyses ◽  
Stem Canker ◽  
Morphological Data ◽  
Initial Inoculum ◽  
Lowbush Blueberry ◽  
Stem Lesions ◽  
Linear Manner ◽  
A New Species

Septoria leaf spot and stem canker is an important disease of lowbush blueberry, but the causal pathogen has not been accurately identified. Based on sequence analysis of the ITS, TEF-1α, RPB2, LSU and β-tubulin genes, the pathogen aligns closely with the genus Sphaerulina. The phylogenetic analyses based on these loci demonstrate that while the pathogen is closely related to the species Sphaerulina amelanchier, it is sufficiently distinct to warrant a new species designation. No ascomata of the teleomorph were found, however, ascospores recovered from leaves fit, morphologically, with the genus Mycosphaerella. The morphological data also support a new species designation. Based on the host that this pathogen infects, we propose the name as Sphaerulina vaccinii and the disease as Sphaerulina leaf spot and stem canker. Under field conditions, it appears that initial inoculum originates from pycnidia on overwintered leaves and stem lesions (cankers) on fruiting stems. More than 90% of the initial inoculum was released during the flowering period from late May through June. Leaf spots began to appear in early June and disease severity increased in a linear manner over time. Secondary inoculum production from diseased foliage was minimal and not considered important epidemiologically. Defoliation resulting from disease began in early July and increased in a non-linear manner thereafter. Manual defoliation of blueberry stems at various times prior to harvest showed the substantial extent to which premature defoliation can affect yield. Stem lesions were also shown to have an impact on yield, even though stems were not killed.

DERMEA PSEUDOTSUGAE N. SP., A CAUSAL AGENT OF PHLOEM NECROSIS IN DOUGLAS FIR

1967 ◽  
Vol 45 (10) ◽  
pp. 1803-1809 ◽  
Author(s):  
A. Funk
Keyword(s):  
British Columbia ◽  
Life History ◽  
New Species ◽  
Douglas Fir ◽  
Causal Agent ◽  
Cultural Characteristics ◽  
Phloem Necrosis ◽  
A New Species ◽  
Extensive Damage

A new species of Dermea is described. The fungus was associated with extensive damage to young Douglas fir (P seudotsuga menziesii) following severe early frosts in the Cariboo Region of British Columbia. Inoculation tests proved the fungus was capable of invading bark wounds and causing necrosis. Life history and cultural characteristics of the fungus are presented. The development of the disease is described and discussed.

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