Factors influencing external fruit rot of cucumber caused by Didymella bryoniae

1982 ◽  
Vol 88 (2) ◽  
pp. 47-56 ◽  
Author(s):  
N. A. M. Steekelenburg
Keyword(s):  
Fruit Rot ◽  
Didymella Bryoniae ◽  
Factors Influencing

Diagnostic Guide for Gummy Stem Blight and Black Rot on Cucurbits

2013 ◽  
Vol 14 (1) ◽  
pp. 35 ◽  
Author(s):  
Anthony P. Keinath
Keyword(s):  
Fruit Rot ◽  
Black Rot ◽  
Fruiting Bodies ◽  
Didymella Bryoniae ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
Foliar Blight ◽  
Stem Cankers

Gummy stem blight and black rot affect all commonly cultivated cucurbits, including melon, watermelon, cucumber, pumpkin, and squash. Symptoms may be found on all vegetative and reproductive parts of plants, although there is variation in susceptibility among species and horticultural types. Characteristic symptoms include foliar blight, crown and stem cankers, and fruit rot. The pathogen, Didymella bryoniae, can be identified from its fruiting bodies of pycnidia and pseudothecia on diseased tissue and in culture. Accepted for publication 27 August 2013. Published 24 October 2013.

scholarly journals First Report of Stagonosporiopsis cucurbitacearum Causing Fruit Rot of Luffa cylindrica in Brazil

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1120-1120 ◽  
Author(s):  
M. Silva ◽  
N. M. Freitas ◽  
H. L. Mendonça ◽  
R. W. Barreto
Keyword(s):  
Tap Water ◽  
Pathogenic Fungi ◽  
Culture Collection ◽  
Fruit Rot ◽  
Small Scale ◽  
Didymella Bryoniae ◽  
Luffa Cylindrica ◽  
Surface Sterilization ◽  
Nucleotide Homology ◽  
Plastic Bags

Luffa cylindrica (Cucurbitaceae) is an Asian vine widely known as the source of loofah (4). In Brazil (local name bucha), it is cultivated by small scale producers as a cash crop. In January 2012, samples of fruits were collected in three areas in the municipality of Cipotânea, state of Minas Gerais (Brazil) bearing rot symptoms. These had large necrotic areas with a grayish epidermis and slightly sunken tissue. Internally, the fibrous parts were necrosed, darkened, and unmarketable. Isolations by surface sterilization of necrotic tissue with 10% bleach and plating onto potato dextrose agar yielded colonies with consistent morphology. A representative culture was deposited in the culture collection of the Universidade Federal de Viçosa (UFV) as COAD1119. Inoculations of seven healthy-appearing L. cylindrica fruits were performed with culture disks obtained from 4-day-old cultures grown on PDA, which were placed onto two points on the epidermis of each of seven fruits. Each point was either intact or previously injured with a sterile needle. Controls consisted of two fruits treated equally but with tap water agar disks in place of fungal inoculum. Fruits were then placed on trays with water-soaked cotton and the trays were wrapped in plastic bags and left over a bench at room temperature for 2 days. The plastic bags were then removed. After 5 days, necrosis was evident and fungal fruit bodies appeared at points with injury. No symptoms appeared on controls. Isolation from diseased tissue yielded colonies identical to those of the inoculated fungus. A dried sample was deposited in the local herbarium at UFV (VIC 32053). Slides were mounted in lactophenol and observed. The fungus had subepidermal perithecia, globose to subglobose, from 75.5 to 134 μm diam.; asci bitunicate, cylindrical, 8-spored; pseudoparaphyses filiform; ascospores fusoid to ellipsoidal, from 26 to 45 μm long and 8 to 11.5 μm wide, one septate, and hyaline. This morphology is consistent with Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae) (3), a broad spectrum pathogen of cucurbits. Genomic DNA was extracted from the isolate growing in pure culture and ITS and LSU sequences were generated and deposited in GenBank under the accession numbers KC582022 and KC582021, respectively. Sequences were compared in BLASTn with other entries in GenBank, and the closest match for each region were S. cucurbitacearum strain CAP14C and D. bryoniae strain CBS 133.96 (JQ936326 and GU456335) with 100% of nucleotide homology for ITS and 100% of nucleotide homology for LSU. Cercospora citrullina and C. cucurbitae have been reported in Brazil on L. cylindrica and mistakenly indicated as synonyms of D. bryoniae (2). To our knowledge, this is the first valid report of S. cucurbitacearum causing fruit rot of loofah in Brazil and the first time pathogenicity to this host has been demonstrated. Losses due to the disease on the crop were reported to be high by growers and management to be difficult since there are no fungicides registered for this crop in Brazil. References: (1) M. M. Aveskamp et al. Stud. Mycol 65:1, 2010. (2) M. A. S. Mendes and A. F. Urben. Fungos em Plantas no Brasil. Brasília, Brazil: EMBRAPA-SPI. Retrieved from http://pragawall.cenargen.embrapa.br/aiqweb/michtml/micbanco01a.asp , 2012. (3) E. Puithalingam and P. Holliday. CMI Descriptions of Pathogenic Fungi and Bacteria 332:1, 1972. (4) J. W. Purseglove. Tropical Crops – Dicotyledons. Longman Group, London, 1968.

Didymella bryoniae. [Descriptions of Fungi and Bacteria].

1972 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Natural Infection ◽  
Seed Transmission ◽  
Stem Canker ◽  
Fruit Rot ◽  
Didymella Bryoniae ◽  
Gummy Stem Blight ◽  
Water Splash ◽  
Characteristic Features

Abstract A description is provided for Didymella bryoniae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Cucurbits (Bryonia, Colocynthis, Cucumis, Cucurbita, Luffa, Momordica and Trichosanthes). DISEASE: Gummy stem blight of Cucurbitaceae, showing a variety of symptoms which are referred to as leaf spot, stem canker, vine wilt and black fruit rot. Lesions on leaves and fruit usually begin as spreading water-soaked areas; in the former these may have a chlorotic halo, become light brown and irregular in outline, leaves can be destroyed. On fruit, dark cracked sunken lesions form, beneath which an extensive rot is found. In the field the first symptoms may be plant collapse where sunken, girdling cankers lead to total loss. Infection also occurs on seedlings. The main characteristic features are the gummy exudate on stem and fruit lesions and the abundant pycnidia followed by perithecia, GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 450, ed. 2, 1970). Records not yet mapped are: Brunei, Mexico, Netherlands, Pitcairn Islands, Republic of Ireland, Salvador. TRANSMISSION: Through conidia by water splash and aerially by ascospores which, in glasshouses in England, had a diurnal periodicity with a peak at 1800-2000 hr (46, 825; 48, 672); and in USA occurred mostly at night (50, 2621). Both spore types may serve as primary inoculum and between-crop survival is an important factor in the epidemiology. Reports on seed transmission are conflicting in cucumber, although seed could be inoculated successfully, no evidence for natural infection was found (48, 322). In the glasshouse transmission by pruning knives has been demonstrated (46, 825).

scholarly journals Watermelon Fruit Disorders

1999 ◽  
Vol 9 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Donald N. Maynard ◽  
Donald L. Hopkins
Keyword(s):  
Citrullus Lanatus ◽  
Phytophthora Capsici ◽  
Unknown Origin ◽  
Fruit Rot ◽  
Black Rot ◽  
Economic Returns ◽  
Didymella Bryoniae ◽  
Bacterial Fruit Blotch ◽  
Gummy Stem Blight ◽  
Blossom End Rot

Watermelon (Citrullus lanatus [Thunb.] Matsum & Nakai) fruit are affected by a number of preharvest disorders that may limit their marketability and thereby restrict economic returns to growers. Pathogenic diseases discussed include bacterial rind necrosis (Erwinia sp.), bacterial fruit blotch [Acidovorax avenae subsp. citrulli (Schaad et al.) Willems et al.], anthracnose [Colletotrichum orbiculare (Berk & Mont.) Arx. syn. C. legenarium (Pass.) Ellis & Halst], gummy stem blight/black rot [Didymella bryoniae (Auersw.) Rehm], and phytophthora fruit rot (Phytophthora capsici Leonian). One insect-mediated disorder, rindworm damage is discussed. Physiological disorders considered are blossom-end rot, bottleneck, and sunburn. Additionally, cross stitch, greasy spot, and target cluster, disorders of unknown origin are discussed. Each defect is shown in color for easy identification.

scholarly journals First Report of Gummy Stem Blight Caused by Didymella bryoniae on Watermelon and Confirmation of the Disease on Pumpkin in Tanzania

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 768-768 ◽  
Author(s):  
B. D. Jensen ◽  
A. Massawe ◽  
I. S. Swai
Keyword(s):  
Citrullus Lanatus ◽  
Morphological Characteristics ◽  
Pathogenic Fungi ◽  
Weather Conditions ◽  
Fruit Rot ◽  
Didymella Bryoniae ◽  
First Report ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
Specific Pcr

Foliar, stem, and fruit lesions were observed on watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and pumpkin (Cucurbita maxima Duchesne) in two separate research fields in the district of Arusha, Tanzania during the warm, rainy season from February to April 2010. Similar symptoms were observed in commercial watermelon fields and intercropped pumpkin fields in Same and Moshi districts with as much as 100% fruit loss in watermelon. Disease symptoms on watermelon were dark brown, V-shaped leaf lesions. On pumpkin, V-shaped leaf lesions were light brown. On both hosts, stems showed water-soaked lesions after rain, which dried up and cracked. On pumpkin, a gummy, amber exudate was seen after rain on stem and fruit lesions. Flowers and fruits of both hosts developed black rot spots and aborted. Isolation of the causal agent on potato dextrose agar (PDA) from leaf and stem pieces of watermelon and pumpkin plants in Arusha showed white-to-olivaceous green mycelium. Pycnidia formed on one-quarter-strength PDA and produced hyaline, oblong conidia mainly with two guttules, nonseptate, 5 to 11 × 3 to 5 μm. Pathogenicity was tested with three isolates from watermelon and one from pumpkin on four 1-month-old plants per watermelon cvs. Sugar Baby and Charleston Grey and pumpkin cv. Small Sugar per isolate. The test was repeated on the watermelon cultivars. One site on the main stem and two leaves per plant were misted, pricked with a scalpel, inoculated with 3-day-old mycelial plugs (5 × 5 mm), and kept humid at 20 to 30°C in cellophane bags for 3 days. All plants developed leaf and/or stem lesions. Detached, misted leaves were also laid on 2% water agar and inoculated as above. Water-soaked lesions developed around inoculation sites and microscopy of infected tissue revealed pycnidia with conidia as described above. All isolates infected both hosts. A set of control plants and detached leaves, mock inoculated with agar plugs, remained symptomless. The fungus was reisolated from infected leaves and stems of both hosts. On the basis of the morphological characteristics, the fungus was identified as Didymella bryoniae (Auersw.) Rehm (anamorph Phoma cucurbitacearum (Fr.:Fr.) Sacc.) (1,3) and this was confirmed by amplification of species-specific PCR products. The isolates from both hosts were cultured in liquid medium, and DNA was extracted using a DNeasy Plant Mini Kit (Qiagen, Valencia, CA). PCR and multiplex PCR involving D. bryoniae-unique primer sequences D6 and D7S, in combination with primer UNLO28S22, produced the expected band sizes (2). To our knowledge, this is the first report of gummy stem blight and black fruit rot of watermelon caused by D. bryoniae in Tanzania, which confirms a previous report of leaf spot on pumpkin (4), and the first report of black fruit rot on pumpkin. The disease was previously an unidentified problem in watermelon and the severe outbreak was associated with favorable weather conditions. References: (1) A. P. Keinath et al. Phytopathology 85:364, 1995. (2) C. A. Koch and R. S. Utkhede. Can. J. Plant Pathol. 26:291, 2004. (3) E. Punithalingam and P. Holliday. No. 332 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1972. (4) E. A. Riley. Mycol. Pap. 75:1, 1960.

scholarly journals Occurrence and Its Condition of Internal Fruit Rot Caused by Didymella bryoniae in Cucumber

2004 ◽  
Vol 10 (4) ◽  
pp. 313-318
Author(s):  
Sang-Yeob Lee ◽  
Soon-Jin Hwang ◽  
Sang-Bum Lee ◽  
Yong-Ki Kim
Keyword(s):  
Fruit Rot ◽  
Didymella Bryoniae ◽  
Internal Fruit Rot
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