Epidemiological aspects of Didymella bryoniae, the cause of stem and fruit rot of cucumber

1983 ◽  
Vol 89 (3) ◽  
pp. 75-86 ◽  
Author(s):  
N. A. M. Steekelenburg
2000 ◽  
Vol 66 (1) ◽  
pp. 12-17 ◽  
Author(s):  
M. KUBOTA ◽  
K. KISHI ◽  
K. ABIKO

2013 ◽  
Vol 14 (1) ◽  
pp. 35 ◽  
Author(s):  
Anthony P. Keinath

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.


2005 ◽  
Vol 21 (4) ◽  
pp. 317-321 ◽  
Author(s):  
Hyeong-Jin Jee ◽  
Kyung-Yeol Ryu ◽  
Chang-Ki Shim ◽  
Ki-Woong Nam

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1120-1120 ◽  
Author(s):  
M. Silva ◽  
N. M. Freitas ◽  
H. L. Mendonça ◽  
R. W. Barreto

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.


1994 ◽  
Vol 43 (1) ◽  
pp. 225-227 ◽  
Author(s):  
J. T. FLETCHER
Keyword(s):  

Author(s):  
E. Punithalingam

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).


Sign in / Sign up

Export Citation Format

Share Document