scholarly journals Morphological characterization and identification of phytophthora species causing citrus gummosis in Kenya

2012 ◽  
Vol 12 (55) ◽  
pp. 7072-7087
Author(s):  
LG Mounde ◽  
◽  
EM Ateka ◽  
AW Kihurani ◽  
L Wasilwa ◽  
...  
Keyword(s):  
Morphological Characterization ◽  
Phytophthora Species ◽  
Soil Samples ◽  
Colony Morphology ◽  
Rough Lemon ◽  
Agroecological Zones ◽  
Mycelial Plug ◽  
Citrus Orchards ◽  
Cornmeal Agar

Frequent outbreaks of citrus gummosis in Kenyan citrus orchards have been reported, yet the identity and distribution of the Phytophthora species causing the disease are unknown. Work was carried out to (i) characterize and identify Phytophthora species associated with citrus gummosis based on cultural and morphological traits and (ii) determine the distribution of these species associated with gummosis in different agroecological zones (AEZ). Some 59 plant and soil samples obtained from symptomatic trees and the rhizosphere were evaluated by direct isolation and baiting, respectively, using Phytophthora semi -selective media. Phytophthora species were identified on the basis of colony morphology, mycelial characteristics, cardinal growth temperatures, morphology and dimensions of sporangia, oogonia and antheridia. For colony morphology and growth temperature studies, a 5 mm diameter mycelial plug of each isolate was transferred to amended cornmeal agar (ACMA) and incubated at 5, 24 and 35°C for 7 days in the dark. Growth rates were evaluated based on daily records of mycelial growth for 7 days. The occurrence and distribution of these species were determined by recording the number of isolates recovered from samples from each AEZ. P. citrophthora was the most prevalent (76.3 %) of all the Phytophthora species identified in all the AEZs, followed by P. nicotianae (22 %). P. syringae was the least (1.7 %) prevalent. P. citrophthora was the only species present in all AEZs sampled whereas P. nicotianae was confined to the coastal lowlands although also present in other zones in a lower scale. P. syringae was present only in low midland zones and was the only species not found in coastal lowland zones. The forty five isolates of P. citrophthora , thirteen isolates of P. nicotianae and one isolate of P. syringae were tested for virulence on fruits of lemon var. rough lemon. The three most virulent isolates of P. citrophthora , two most virulent isolates of P. nicotianae and the only isolate of P. syringae were selected for pathogenicity testing on lemon seedlings. Based on these studies, it may be concluded that P. citrophthora, P. nicotianae (syn. P. parasitica) and P. syringae are the Phytophthora species associated with citrus gummosis in Kenya. Molecular characterization of the pathogens is recommended to confirm true genetic identity of the species.

scholarly journals Molecular and morphological characterization of Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 from Egypt

2021 ◽  
Vol 13 (4) ◽  
pp. 11083
Author(s):  
Sanaa A. HAROON ◽  
Zafar HANDOO ◽  
Mihail KANTOR ◽  
Andrea SKANTAR ◽  
Maria HULT
Keyword(s):  
Solanum Tuberosum ◽  
Nematode Species ◽  
Morphological Characterization ◽  
Globodera Rostochiensis ◽  
Cyst Nematode ◽  
Soil Samples ◽  
Potato Cyst Nematode ◽  
Cultivated Land ◽  
Zigzag Pattern

The golden potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Skarbilovich (1959) is a damaging soilborne quarantine pest of Solanum tuberosum (potato) and other solanaceous crops worldwide. In spring of 2021 a survey was conducted in area of Abo El Matamer, Bahera governorates in Egypt. Soil samples were taken in zigzag pattern throughout 65 acres of potato cultivated land and processed in Nematology lab, Fayoum University, Egypt. In June 2021, two hundred soil samples were collected from nearby areas to evaluate the distribution of this potato cyst nematode in other cultivated land located in area of first infection but fortunately the golden potato cyst nematode was not detected from neighboring locations. The nematode species was identified by both morphological and molecular means as Globodera rostochiensis. To our knowledge this is the first molecular and morphological characterization of G. rostochiensis from Egypt.

scholarly journals Diversity of Insecticidal Crystal proteins (ICPs) of indigenous Bacillus thuringiensis strains

2018 ◽  
Vol 5 ◽  
pp. 11-18
Author(s):  
Ganga G.C. ◽  
Charu Arjya ◽  
Yamuna Khadka ◽  
Sabina Dhamala
Keyword(s):  
Bacillus Thuringiensis ◽  
Slight Modification ◽  
Soil Samples ◽  
Colony Morphology ◽  
Selective Enrichment ◽  
Crystal Proteins ◽  
Selection Protocol ◽  
White Type ◽  
Insecticidal Crystal Proteins

Objectives: The purpose of this study was to characterize the indigenous Bacillus thuringiensis (Bt) isolated from the soil samples of central development region of Terai. Methods: A total of 50 soil samples collected from cultivated and barren fields of Terai region. Isolation was carried out using the acetate selection protocol as described by (Russell and Al 1987) with a slight modification. The Nutrient broth (NB) was acetated by using 0.25M sodium acetate which is a selective enrichment method for isolation of Bt. Characterization of the isolate was done by phenotyping methods (microscopy and biochemical). Results: No distinct variation was observed between the isolates of cultivable and uncultivable lands. Bt were categorized into7 different types based on colony morphology. The dominant colony was fried egg type identical with the reference strain, followed by flat white type of colony. The result showed that even though the colony morphology is same but the ICPs (Insecticidal crystal proteins) shapes produced by them vary, rod shapes (53.57%), spherical (10.71%), ovoid (8.3%), amorphous (17.85%), capheaded (9.5%). ICPs morphology reveal the cry1, cry2, cry3, cry4, cry8, cry 9, cry10 and cry11 types of gene may be present in the native isolates. Conclusion: This study represents the first report of several indigenous Bacillus thuringiensis strains with significantly different ICPs producing stains from hot tropical climate.

scholarly journals PRESENCE AND INOCULUM DENSITY OF Phytophthora IN DIFFERENT COCONUT CULTIVARS IN DAVAO RESEARCH CENTER (DRC)

CORD ◽  
2004 ◽  
Vol 20 (01) ◽  
pp. 34
Author(s):  
N.C.S.J. Bachiller
Keyword(s):  
Morphological Characterization ◽  
Soil Samples ◽  
West African ◽  
Yellow Dwarf ◽  
Phytophthora Palmivora ◽  
Leaf Axil ◽  
Dilution Plate ◽  
Organic Debris ◽  
Positive Results

Presence of Phytophthora palmivora was both obtained in the soil samples and organic debris layed in leaf axil of coconut.  Block planted to CAMT x MRD hybrid had the highest number of Phytophthora propagules (2.0).  This was followed by CAMT (1.4) and KINGD (1.1).  Aromatic and Catigan Green Dwarf  had the least Phytopthora propagules collected.   Isolation of Phytophthora from the soil samples and organic debris  from leaf axil was done thru dilution plate and baiting method respectively using six month old Malayan Red Dwarf (MRD) nuts.  Highest infection (100%) on bait nuts was also obtained in CAMT x MRD hybrid 3.5 days after inoculation.  Reisolation of Phytophthora from bait nuts gave positive results.  Morphological characterization of the sporangium showed considerable variation in shapes and size.   More Phytophthora propagules was obtained in soil samples collected in areas previously planted with Malayan Yellow Dwarf x West African Tall (MAWA).  Phytophthora palmivora is basically a soil borne pathogen but could easily be transported by wind and rainsplash, tent building ants and flying beetles,.

scholarly journals Karakterisasi Morfologi Phytophthora sp. Asal Buah Kakao Desa Olo-oloho, Kabupaten Konawe, Sulawesi Tenggara

2020 ◽  
Vol 7 (1) ◽  
pp. 1064
Author(s):  
Muzuni Muzuni ◽  
Haidin Haidin ◽  
Nur Arfa Yanti
Keyword(s):  
Cell Morphology ◽  
Morphological Characteristics ◽  
Morphological Characterization ◽  
Point Method ◽  
Colony Morphology ◽  
Vegetable Juice ◽  
Agar Media

This study aimed to determine the morphological characteristics of Phytophthora sp. isolated from cocoa fruits from Olo-oloho Village, Konawe Regency, Southeast Sulawesi. Isolation of Phytophthora sp. carried out by the point method using V4 (Vegetable Juice Agar) media incubated at 27ºC for 24 hours. Morphological characterization of Phytophthora sp. included characterization of colony morphology and cell morphology. The results showed that the colony morphological characteristics were white colonies, cotton-like textures, the uneven edge of the colony, zoning and radial lines. The morphological characteristics of the cell had asexual spores in the form of sporangium and chlamydospores, hyphae are not aseptic, greenish-black zoospores, zoospores are round and double-flagged, and have sporangiophores. Keywords: Phytophthora sp., colony morphology, cell morphology

scholarly journals PRESENCE AND INOCULUM DENSITY OF Phytophthora IN, DIFFERENT COCONUT CULTIVARS IN DAVAO, PHILIPPINES

CORD ◽  
2004 ◽  
Vol 20 (01) ◽  
pp. 34
Author(s):  
N.C.S.J. Bachiller
Keyword(s):  
Morphological Characterization ◽  
Soil Samples ◽  
West African ◽  
Yellow Dwarf ◽  
Phytophthora Palmivora ◽  
Leaf Axil ◽  
Dilution Plate ◽  
Organic Debris ◽  
Positive Results

Phytophthora palmivora was present in the soil samples and organic debris deposited in leaf axil of coconut. Block planted with CAMT x MRD hybrid had the highest number of Phytophthora propagules (2.0) followed by CAMT (1.4) and KINGD (1.1). Aromatic and Catigan Green Dwarf had the least Phytopthora propagules. Isolation of Phytophthora from the soil samples and organic debris from leaf axil was done through dilution plate and baiting method respectively using six month old Malayan Red Dwarf (MRD) nuts. Highest infection (100%) on bait nuts was also obtained in CAMT x MRD hybrid 3.5 days after inoculation. Reisolation of Phytophthora from bait nuts gave positive results. Morphological characterization of the sporangium showed considerable variation in shapes and size. More Phytophthora propagules was obtained in soil samples collected in areas previously planted with Malayan Yellow Dwarf x West African Tall (MAWA). Phytophthora palmivora is basically a soil borne pathogen but could easily be transported by wind and rainsplash, tent building ants and flying beetles.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

Morphological Characterization of Rhinacanthus Species of Sri Lanka

Planta Medica ◽  
2010 ◽  
Vol 76 (05) ◽  
Author(s):  
APPR Amarasinghe ◽  
RP Karunagoda ◽  
DSA Wijesundara
Keyword(s):  
Sri Lanka ◽  
Morphological Characterization

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

Density and morphological characterization of bacteria in integrated and exclusive production systems

2020 ◽  
Vol 13 (11) ◽  
pp. 1
Author(s):  
A. R. B. Zanco ◽  
A. Ferreira ◽  
G. C. M. Berber ◽  
E. N. Gonzaga ◽  
D. C. C. Sabino
Keyword(s):  
Bacterial Community ◽  
Rainy Season ◽  
Production Systems ◽  
Cropping System ◽  
Morphological Characterization ◽  
Native Forest ◽  
Exclusive Production ◽  
Colony Forming Units

The different integrated production systems can directly interfere with its bacterial community. The present study aimed to assess density, bacterial diversity and the influence of dry and rainy season in different integrated and an exclusive production system. The fallow and a native forest area was assessed to. Samples were collected in 2012 March and September. The isolation were carried out into Petri dishes containing DYGS medium. The number of colony forming units (CFU) was counted after 48 hours and. The bacterial density ranged between 106 and 107 CFU g-1 soil. The crop system affected the dynamics of the bacterial community only in the rainy season. The rainy season showed greater density of total bacteria when compared to the dry period regardless of the cropping system. The dendrograms with 80 % similarity showed thirteen and fourteen groups in the rainy and dry seasons. Isolates with the capacity to solubilize phosphate in vitro were obtained from all areas in the two seasons, but this feature has been prevalent in bacteria isolated during the rainy season

Characterization of Antibacterial-Producing Endophytic Fungi of Syzygiumpolyanthum Leaves

2020 ◽  
Vol 20 (4) ◽  
pp. 448-454
Author(s):  
Rahmita Burhamzah ◽  
Gemini Alam ◽  
Herlina Rante
Keyword(s):  
Molecular Characterization ◽  
Endophytic Fungi ◽  
Morphological Characterization ◽  
Test Method ◽  
Analysis Method ◽  
Nitrogen Base ◽  
Rdna Genes ◽  
Antibacterial Screening ◽  
Planting Method

Background: Endophytic fungi live in plants’ tissue and can produce the same bioactive compounds as its host plant produces. Syzygiumpolyanthum leaves have known to be one of the antibacterial compound producers. Aim and Objective: This study aimed to characterize morphologically, microscopically, and molecularly the antibacterial-producing endophytic fungi of Syzygiumpolyanthum leaves. Methods: The isolation of endophytic fungi was done by fragment planting method on PDA medium. The antibacterial screening was performed using the antagonistic test as the first screening followed by the disc diffusion test method. The morphological characterization was based on isolate’s mycelia color, growth pattern, margin, and surface texture of the colony, while the microscopic characterization was based on its hyphae characteristics. The molecular characterization of the isolate was done by nitrogen base sequence analysis method on nucleotide constituent of ITS rDNA genes of the isolate. Results: The results found that isolate DF1 has antibacterial activity against E.coli, S.aureus, P.acne, and P.aeruginosa, with the greatest inhibition at 10% concentration of broth fermentation extract on S.aureus with a diameter of inhibition of 13.77 mm. Conclusion: Based on macroscopic, microscopic, and molecular characterization, DF1 isolate is similar to Ceriporialacerate.

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