scholarly journals First Report of Fusarium oxysporum Causing a Leaf Twisting Disease on Allium cepa var. ascalonicum in Sri Lanka

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 695-695 ◽  
Author(s):  
P. U. Kuruppu
Keyword(s):  
Sri Lanka ◽  
Fusarium Oxysporum ◽  
Allium Cepa ◽  
Neck Region ◽  
Single Spore ◽  
Disease Symptoms ◽  
The North ◽  
Pathogenicity Tests ◽  
Colletotrichum Spp ◽  
North Western

A disease of shallot onions, Allium cepa var. ascalonicum, that caused yield losses of up to 20 to 30% in some fields was reported from Kalpitiya Peninsula in the North Western Province of Sri Lanka in the late 1980s. Disease symptoms consisting of chlorosis followed by curling and twisting of leaves and abnormal elongation of the neck region appeared after germination of the onion bulbs, subsequently causing plant collapse. Symptomatic plants occurred randomly in most fields and the disease was prevalent throughout the year. Tissue pieces from leaves and the neck region of symptomatic plants plated on potato dextrose agar containing 1% streptomycin (PDAS) produced purplish pink fungal colonies identified as Fusarium oxysporum. Pathogenicity tests were performed with single-spore fungal isolates grown at 25°C for 14 days on PDAS. Shallot onion cv. Vathalan was inoculated by soaking bulbs, pierced with a sterilized needle, in a spore suspension containing 2 × 106 spores per ml for 10 min. Control bulbs were wounded, and soaked for 10 min in sterilized water. Bulbs were then planted in sterile sand and maintained in a green house at 25 to 28°C. After 2 to 3 weeks, typical symptoms, as observed in the field, developed in plants produced from bulbs inoculated with the F. oxysporum isolate. Symptoms were not observed on plants from the control bulbs. Koch's postulates were confirmed by reisolating the same fungus from the neck region of diseased plants. Onion twister disease described by Ebenebe (1) also had been observed in this region in Sri Lanka during 1992-1993. There were differences between these two diseases in disease symptoms and disease development in the field. Acer-vuli of Colletotrichum spp. were always detected in lesions of the neck region, as well as on leaf blades, of plants severely affected by onion twister disease. This disease developed from foci in fields that spread over time. Moreover, onion twister disease occurred only from October until January, coinciding with the rainy season. Reference: (1) A. C. Ebenebe. Plant Dis. 64:1030, 1980.

Prevalence and Molecular Characteristics of Vibrio spp. Isolated from Preharvest Shrimp of the North Western Province of Sri Lanka

2012 ◽  
Vol 75 (10) ◽  
pp. 1846-1850 ◽  
Author(s):  
MADURA SANJEEVANI GONSAL KORALAGE ◽  
THOMAS ALTER ◽  
DUANGPORN PICHPOL ◽  
ECKHARD STRAUCH ◽  
KARL-HANS ZESSIN ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Penaeus Monodon ◽  
Molecular Characteristics ◽  
Pathogenic Potential ◽  
Western Province ◽  
The North ◽  
Geographical Regions ◽  
Seafood Products ◽  
North Western ◽  
Vibrio Spp

This study investigated the prevalence and molecular characteristics of Vibrio spp. in farmed shrimp (Penaeus monodon) in Sri Lanka. A total of 170 shrimp samples (100 g of whole shrimp each) taken from individual ponds from 54 farms were collected 1 week prior to harvest from the North Western Province of Sri Lanka. Overall, 98.1% of the farms and 95.1% of the ponds were positive for Vibrio spp. in shrimp; at the pond level, V. parahaemolyticus (91.2%) was most common, followed by V. alginolyticus (18.8%), V. cholerae non-O1/non-O139 (4.1%), and V. vulnificus (2.4%). Multiple Vibrio spp. were detected in 20.6% of the ponds. None of the V. parahaemolyticus isolates (n = 419) were positive for the virulence-associated tdh (thermostable direct hemolysin) and trh (TDH-related hemolysin) genes. V. cholerae was confirmed by the presence of ompW, and all isolates (n = 8) were negative for the cholera toxin (ctxA) gene. V. cholerae isolates were serogrouped by PCR and identified as V. cholerae non-O1/non-O139. All four V. vulnificus strains, isolated from different ponds of two geographical regions, showed pathogenic potential; they belonged to vcgC sequence type, type B 16S rRNA genotype and contained a pilF polymorphism associated with human pathogenicity. The results of this study revealed the ubiquitous nature of vibrios in farmed shrimp. To minimize the potential risk of Vibrio infections due to handling or consumption of raw or undercooked seafood products, good manufacturing practices as well as proper handling and processing should be addressed.

scholarly journals Isolation, molecular characterization and phylogeny of Naegleria species in water bodies of North-Western Province, Sri Lanka

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248510
Author(s):  
Nuwan Gunarathna ◽  
Anjalie Amarasinghe ◽  
Sunil Wijesundara ◽  
Devika Iddawela ◽  
Susiji Wickramasinghe
Keyword(s):  
Phylogenetic Analysis ◽  
Sri Lanka ◽  
Bayesian Analysis ◽  
Molecular Characterization ◽  
Its Region ◽  
Water Bodies ◽  
Internal Transcribed Spacer Region ◽  
Western Province ◽  
The North ◽  
North Western

Background The inland freshwater bodies in the North-Western Province of Sri Lanka have ideal environmental conditions for the Naegleria species. Therefore, the presence and prevalence of Naegleria species in the water bodies of North-Western Province were determined by molecular characterization and phylogenetic analysis in this study. Methods A total of 104 water bodies were selected from Kurunegala and Puttalam districts in the North-Western Province of Sri Lanka. Mean turbidity, pH, and temperature were recorded in each water body from three selected site. Centrifuged samples were cultured on non-nutrient agar plates with Escherichia coli. Enflagellation test positive isolates were subjected to DNA extraction and polymerase chain reaction using genus and species-specific primers targeting the internal transcribed spacer region (ITS) and Mp2CL5 gene. Phylogenetic analysis was performed using Bayesian and maximum likelihood (ML) methods. Results The prevalence of Naegleria species and N. fowleri in the study area were 23.07% and 1.92%. The prevalence of Naegleria species and the physicochemical parameters of the water bodies showed no significant correlation. Bayesian analysis of the ITS region revealed the Naegleria Sri Lankan (SL) isolates 1, 3, and 4 in a single clade separated from the 2 and 5. Furthermore, Bayesian analysis identified isolates 2 and 5 in the same clade with Naegleria sp. samples and N. Philippinensis forming a sister clade. However, in the ML tree, all isolates were in the same clade with Naegleria sp. samples and N. Philippinensis. Conclusions The present study reports the first isolation of pathogenic N. fowleri from Sri Lanka. Based on Bayesian analysis, SL isolates 2 and 5 form a separate clade from 1, 3, and 4. However, in ML analysis, all isolates are grouped in one clade with Naegleria sp. samples and N. philippinensis. Further investigations are required to confirm these findings.

New insights into the identities of the elasmobranch fauna of Sri Lanka

Zootaxa ◽  
2019 ◽  
Vol 4585 (2) ◽  
pp. 201
Author(s):  
DANIEL FERNANDO ◽  
ROSALIND M. K. BOWN ◽  
AKSHAY TANNA ◽  
RAMAJEYAM GOBIRAJ ◽  
HANNAH RALICKI ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Sequence Data ◽  
Neighbor Joining ◽  
Civil Unrest ◽  
The North ◽  
Landing Sites ◽  
Elasmobranch Species ◽  
The Persian Gulf ◽  
First Time ◽  
North Western

Identities of elasmobranchs from Sri Lanka encountered during collections conducted in an intensive nine-day survey of fish markets and landing sites at 11 localities in the North Western, Northern, and Eastern Provinces in March of 2018 were assessed. In total, 111 specimens representing 34 elasmobranch species were examined. Sequence data for the NADH2 gene were generated for all specimens. Independent Neighbor-Joining analyses, which included data for related taxa, were conducted for 25 subgroups of elasmobranchs to help confirm specific identifications. Five of the 34 species encountered are likely new to science. These consist of one species each of the batoid genera Brevitrygon, Narcine, and Torpedo, and the selachian genera Centrophorus, and Chiloscyllium. The specific identities of 12 species previously known to occur in Sri Lanka are updated to conform to current taxonomy; four of these (Gymnura cf. poecilura 2, Carcharhinus cf. limbatus, Echinorhinus sp. 1, and Iago cf. omanensis 1) represent what appear to be undescribed species reported previously from other localities. Three species (Maculabatis arabica, Acroteriobatus variegatus, and Centroscymnus owstonii) are reported from Sri Lanka for the first time; the latter species also represents the first documented record of this genus and family for the island nation. One of the two specimens on which the recent description of the new species of Planonasus indicus was based was also collected as part of this survey. Although some of the species confirmed to occur in Sri Lanka have also been found in India, others were previously known only from the Persian Gulf, Gulf of Oman, or localities in Southeast Asia. The high amount of novelty discovered as a result of a survey of such short duration emphasizes the importance of more intensive survey efforts in this region now that the civil unrest that precluded such work for nearly three decades has come to an end. 

scholarly journals Morphology and ectoparasite spectrum of Pteropus vampyrus (the flying fox) in different parts of Malakand Division, Pakistan

2020 ◽  
Vol 80 (3) ◽  
pp. 523-528
Author(s):  
W. Khan ◽  
N. N. Nisa ◽  
S. Ullah ◽  
B. Rehbar ◽  
S. Ahmad ◽  
...  
Keyword(s):  
Neck Region ◽  
Parasite Fauna ◽  
Head Region ◽  
Clear Cut ◽  
The North ◽  
Significant Difference ◽  
Key Factor ◽  
Pteropus Vampyrus ◽  
North Western ◽  
Flying Fox

Abstract Three districts viz. Lower Dir, Swat and Shangla in Khyber Pakhtunkhwa province, were surveyed for the collection of Pteropus vampyrus (the Indian flying fox) in Malakand division, the north western region of Pakistan from February to November 2018. A total of 35 specimens were captured. Out of the examined specimens 22 were found to be infected with ectoparasites. Three types of ectoparasites were observed including flies 20% (n=7/35), mites 28.5% (n=10/35) and bugs 14.2% (n=5/35). Male bats were more infected 57.1% (n=20/35) as compared to females 42.8% (n=15/35), however, no significant difference (p>0.05) was noted. Flies were recovered from wings membrane and head region, mites were found on wings, ears and around eyes while bugs were found attached on body surface and neck region. Body weight, circumference and wing span of male bats were greater as compared to female bats and were considered a key factor in clear cut identification of male and female Pteropus vampyrus (the Indian flyingfox). It was concluded that Pteropus vampyrus from north western part of Pakistan were parasitized by a varied parasite fauna with high infestation rates. We assume that in male bats the number of parasites is generally higher than in females. Our results revealed new insights into parasite fauna of Pteropus vampyrus.

Pericladium grewiae. [Descriptions of Fungi and Bacteria].

1988 ◽  
Author(s):  
J. E M. Mordue
Keyword(s):  
Sri Lanka ◽  
Geographical Distribution ◽  
South India ◽  
Western Himalaya ◽  
The North ◽  
Water Splash ◽  
North Western

Abstract A description is provided for Pericladium grewiae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Grewia spp., including G. columnaris, G. hirsuta, G. mollis, G. orbiculata, G. retusifolia, G. villosa; G. rotundifolia and G. tiliaefolia (as P. tiliacearum); G. flavescens (as P. flavesci). DISEASE: Stem smut of Grewia. Infection frequently results in the production of conspicuous witches' brooms. GEOGRAPHICAL DISTRIBUTION: Africa: Angola, Ethiopia. Asia: India (including Mysore, the north-western Himalaya, Rajasthan, south India), Sri Lanka. Australasia: Australia. TRANSMISSION: Ustilospores are presumably disseminated by air currents and water-splash. Young and mature plants are both susceptible (Josh, 1957), but no detailed studies have been reported.

Use of regression techniques for rice yield estimation in the North-Western province of Sri Lanka

2021 ◽  
Vol 50 (4) ◽  
pp. 439
Author(s):  
E. M. P. Ekanayake ◽  
L. C. D. Wickramasinghe ◽  
R. T. Weliwatta
Keyword(s):  
Sri Lanka ◽  
Rice Yield ◽  
Yield Estimation ◽  
Western Province ◽  
The North ◽  
Regression Techniques ◽  
North Western

scholarly journals Identification of Colletotrichum Species Associated with Blueberry Anthracnose in Sichuan, China

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 718
Author(s):  
Xuan Liu ◽  
Xiaojuan Zheng ◽  
Muhammad Ibrahim Khaskheli ◽  
Xiaofang Sun ◽  
Xiaoli Chang ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Economic Losses ◽  
Single Spore ◽  
Purification Method ◽  
Colletotrichum Fructicola ◽  
Pathogenicity Tests ◽  
Colletotrichum Spp ◽  
Important Disease

Anthracnose caused by Colletotrichum spp. is an important disease of blueberries and results in large economic losses for blueberry growers. Samples of anthracnose were collected from six main blueberry cultivation areas in Sichuan Province. In total, 74 Colletotrichum isolates were obtained through a single-spore purification method and identified to the species through morphological characteristics and phylogenetic analyses based on partial DNA sequences of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), internal transcribed spacer (ITS) regions, and the β-tubulin (TUB2), actin (ACT) and calmodulin (CAL) genes. Among all species, Colletotrichum fructicola was the most dominant species, with an isolation percentage of up to 66.2% in Sichuan, followed by Colletotrichum siamense (17.6%), C. kahawae (5.4%), C. karstii (5.4%), C. nymphaeae (2.7%) and C. sichuaninese (2.7%). Pathogenicity tests showed all species were able to cause typical anthracnose symptoms on blueberry leaves and stems. Colletotrichum fructicola was the predominant species with strong aggressiveness. Moreover, C. fructicola, C. kahawae, C. sichuaninese and C. nymphaeae are first reported here to cause blueberry anthracnose. This study provides a comprehensive reference for the association of different Colletotrichum spp., which may support the sustainable management of blueberry anthracnose.

scholarly journals Lisianthus Crown and Stem Rot Caused by Fusarium avenaceum in Central Italy

Plant Disease ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 304-304 ◽  
Author(s):  
S. Pecchia
Keyword(s):  
Central Italy ◽  
Fusarium Avenaceum ◽  
Stem Rot ◽  
Conidial Suspension ◽  
Single Spore ◽  
Disease Symptoms ◽  
Agar Plug ◽  
Pathogenicity Tests ◽  
Site Control ◽  
New Industry

Lisianthus (Eustoma russelianum, syn. E. grandiflorum), a member of the Gentian family, is grown in the greenhouse in Italy as a commercial cut-flower crop. Its cultivation is a relatively new industry with high economic potential. However, disease problems have been observed on various greenhouse-planted lisianthus in Central Italy (Tuscany): symptoms of wilting, tan leaf flecks, tan stem discoloration, crown and stem rot, and death. White mycelia and orange sporodochia were also commonly observed on diseased crowns and stems. Fusarium avenaceum isolates were recovered from diseased tissues. Four single-spore isolates were selected for artificial inoculation. Pathogenicity tests were conducted in the greenhouse on 16- to 17-week-old E. russelianum plants, cvs. Mariacki, Echo, and Heidi, by placing a colonized agar plug, or drops of a conidial suspension, at the crown previously wounded with a sterile scalpel. Moist cotton was fastened to the wound site. Control plants were inoculated with sterile agar plugs or drops of sterile, distilled water. Five plants per cultivar and per treatment were used for each isolate. All plants developed typical disease symptoms within 1 or 2 weeks when inoculated with mycelial plugs or conidial suspensions, respectively. Control plants developed no symptoms. Koch's postulates were completed by consistently reisolating the pathogen from inoculated plants. This is the first report of F. avenaceum on lisianthus in Italy and is similar to reports of the disease in California and Florida (1,2). References: (1) S. T. Koike et al. Plant Dis. 80:1429, 1996. (2) R. J. McGovern et al. Phytopathology 87:S64, 1997.

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