scholarly journals Incidence and management of Colletotrichum gloeosporioides canker on Jatropha curcas L. in Ibadan, southwestern Nigeria

2020 ◽  
Vol 24 (10) ◽  
pp. 1811-1814
Author(s):  
J.O. Nwogwugwu ◽  
A.A. Batcho ◽  
I Time
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Laboratory Data ◽  
Plant Diseases ◽  
Economic Losses ◽  
Dual Culture ◽  
Southwestern Nigeria ◽  
Environmental Consequences ◽  
Randomized Design ◽  
The Impact

The Impact of fungal pathogens on man is enormous, stretching from infecting humans to destroying a third of all food crops annually thereby causing economic losses and impacting global poverty. As a result, fungal disease incidence was assessed under natural field infection and data were collected randomly from 12 months old jatropha seedlings with cankers. Colletotrichum spp. isolated from the diseased sampled were interacted with known fungi and bacteria biocontrol agents. The experiment was carried out on completely randomized design (CRD) in the laboratory. Data were analyzed using ANOVA and statistically different means were separated using LSD (p≤0.05). The dual culture interaction proved that all the BCA used, possessed antagonistic potential, and could serve best for prophylactic protection. Plant diseases may be suppressed by the activities of one or more plant-associated microbes hence keeping them in check below threshold levels. This will help to maintain the quality and abundance of food, thereby mitigating hunger. Negative environmental consequences caused by excessive use and misuse of agrochemicals, requires that healthier and costeffective approaches to disease management should be adopted. Keywords: Biodiesel; Agrochemicals; Biocontrol agent; Dual culture; Pathogens

scholarly journals Morphological and pathogenic characterization of Fusarium oxysporum in lulo (Solanum spp.)

2021 ◽  
Vol 38 (1) ◽  
pp. 20-37
Author(s):  
Yohana Patricia Anama ◽  
Ricardo Díaz ◽  
David Esteban Duarte-Alvarado ◽  
Tulio Cesar Lagos-Burbano
Keyword(s):  
Growth Rate ◽  
Fusarium Oxysporum ◽  
Fungal Pathogens ◽  
Disease Incidence ◽  
Morphological Characterization ◽  
Sources Of Resistance ◽  
Randomized Design ◽  
Two Factors ◽  
Height Increase ◽  
Genotype G1

Fusarium oxysporum is one of the most limiting fungal pathogens of lulo crop. To determine its pathogenicity, this work morphologically and pathogenically characterized F. oxysporum isolates from different lulo-growing municipalities of the Department of Nariño. Twenty isolates were evaluated through a completely randomized design with two factors and three replicates per treatment, including a control. The first factor corresponded to 20 isolates of F. oxysporum and the second to 10 lulo genotypes. The morphological characterization involved determining growth rate (GR), color (CO), mycelial type (MT), medium coloration (Mc), shape (Sh), size (S), number (N) of macroconidial (Ma) and microconidial (Mi) septa, presence of chlamydospores (PC), and chlamydospore shape (CS). Moreover, the pathogenic characterization was based on the incubation period (IP), absolute growth rate (AGR), disease severity (DS), disease incidence (I), and vascular discoloration (VD). The morphological characterization demonstrated that all isolates corresponded to F. oxysporum. For IP, genotype G1 showed the lowest average at 18 days. For AGR, genotype G2 had the lowest height increase at 0.05 cm.day-1. For DS, genotype G1 reached the highest severity level (level 9) and a disease incidence of 100%. This study provides the first report of the special form of F. oxysporum f. sp. quitoense in Nariño. Solanum hirtum, Solanum sessiliflorum, and Solanum estramonifolium were resistant to the isolates evaluated, demonstrating that wild species should be considered as sources of resistance for breeding programs aiming to obtain resistant commercial genotypes.

scholarly journals Incidence of leaf blight disease of Egusi melon in South-west Nigeria

2020 ◽  
Vol 28 (2) ◽  
pp. 255-265
Author(s):  
J.F. Ogunsola ◽  
B. Ikotun ◽  
K.E. Ogunsola
Keyword(s):  
Fungal Pathogens ◽  
Citrullus Lanatus ◽  
Disease Incidence ◽  
Leaf Blight ◽  
Economic Damage ◽  
Colletotrichum Truncatum ◽  
Southwestern Nigeria ◽  
Lasiodiplodia Theobromae ◽  
Ondo State ◽  
Blight Disease

Egusi melon (Citrullus lanatus (Thumb) Mansf.) is an important vegetable crop grown for edible seeds and oil in West Africa. Leaf Blight Disease (LBD) is one of the major constraints to its production, with potential to cause economic damage. The objective of this study was to investigate the incidence and distribution of leaf blight on Egusi melon in Southwestern Nigeria. A survey of LBD of Egusi melon was conducted in 2015 and 2016, in five southwestern States of Nigeria (Ogun, Oyo, Osun, Ekiti and Ondo States). Twenty plants each, were randomly sampled from 150 farms comprising 30 farms each, from each State. The distribution of different Egusi melon varieties planted was recorded. “Bara” cv. was the most cultivated variety (51.6%); followed by “Bojuri” (30.4%) and “Serewe” (18%). Leaf blight was observed in most farms in the five States, from 73% in Osun and Oyo states to 83% in Ondo State. Disease incidence and severity varied with locations and cultivars, and ranged from 0.0-87.5±18% and 1.0±0-4.5±0.8 in Osun State to 20.0±19 - 95.0±4.5% and 2.3±1.5 - 5.0±0 in Ondo State. Out of the twelve fungal pathogens from ten genera isolated from infected plants, only Colletotrichum truncatum, C. gloeosporioides and Lasiodiplodia theobromae caused Leaf blight on Egusi melon. Key words: Colletotrichum gloeosporioides, Colletotrichum truncatum, Lasiodiplodia theobromae

scholarly journals 187 Effect of Nutrient Source on Quality and Yield of Strawberry Grown in Verticillium-infested Soil

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 474D-474
Author(s):  
V. Mitchell ◽  
C. Brooks ◽  
M. Morant
Keyword(s):  
Disease Incidence ◽  
Titratable Acidity ◽  
Threshold Level ◽  
Soluble Solids ◽  
Organic N ◽  
Economic Losses ◽  
Infested Soil ◽  
Alternative Source ◽  
Solids Content ◽  
The Impact

Verticillium albo-atrum, a cosmopolitan pathogen that causes wilt of strawberry, can cause economic losses for growers and increased prices for consumers. This study was conducted in 1998 to assess the impact of organically and inorganically supplied N on fruit yield and quality. `Allstar' (resistant) and `Raritan' (susceptible) varieties of strawberry were planted in V. albo-atrum-infested soil that was amended with poultry compost (organic N) or ammonium nitrate (inorganic N). Fruit quality was assessed as titratable acidity (TA), soluble solids content (SSC) using a refractometer, and reducing sugars concentration using a gas chromatography. Disease incidence was below threshold level and did not affect the results of this study. Plants grown in compost amended plots produced an average of 41 fruit, weighing 354 g, compared to the 34.5 fruit weighing 487 g that were harvested from the inorganically amended plots. TA was not affected by the treatments. Overall, yield of `Raritan' was 40% greater than that of `Allstar'. The SSC of `Allstar' was highest in fruit that were produced in compost-amended soil in contrast to that of `Raritan', which was greatest for plants that were grown in the inorganically amended plots. Fruit grown in the inorganically amended plots generally had a higher concentration of glucose and fructose, but sucrose was found only in fruit from the control plots. Poultry compost may be an alternative source of N for producing strawberries but this needs to be further evaluated because of the slower release of nutrients over time.

scholarly journals Identification and Characterization of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2430-2445 ◽  
Author(s):  
Shan Lin ◽  
Nancy J. Taylor ◽  
Francesca Peduto Hand
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Phylogenetic Analyses ◽  
Management Strategies ◽  
Morphological Characterization ◽  
Fruit Rot ◽  
Economic Losses ◽  
Yield Reduction ◽  
Inoculum Concentration ◽  
Fruit Samples

Cut branches of deciduous holly (Ilex spp. L.) harboring colorful berries are traditionally used as ornaments in holiday decorations. Since 2012, a fruit rot of unspecified cause has resulted in significant yield reduction and economic losses across Midwestern and Eastern U.S. nurseries. In this study, symptomatic fruit samples collected from nine different locations over five years were analyzed, and several fungal species were isolated. A combination of morphological characterization, multilocus phylogenetic analyses, and pathogenicity assays revealed that Alternaria alternata and Diaporthe ilicicola sp. nov. were the primary pathogens associated with symptomatic fruit. Other fungi including A. arborescens, Colletotrichum fioriniae, C. nymphaeae, Epicoccum nigrum, and species in the D. eres species complex appeared to be minor pathogens in this disease complex. In detached fruit pathogenicity assays testing the role of wounding and inoculum concentration on disease development, disease incidence and severity increased when fruit was wounded and inoculated with a higher inoculum concentration. These findings indicate that management strategies that can protect fruit from injury or reduce inoculum may lower disease levels in the field. This research established the basis for further studies on this emerging disease and the design of research-based management strategies. To our knowledge, it also represents the first report of species of Alternaria, Colletotrichum, Diaporthe, and Epicoccum causing fruit rot of deciduous holly.

scholarly journals First Report of Pythium myriotylum Causing Root and Stem Rot on Tobacco in Zimbabwe

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1067-1067 ◽  
Author(s):  
T. E. Sigobodhla ◽  
S. Dimbi ◽  
A. J. Masuka
Keyword(s):  
South Carolina ◽  
Production System ◽  
Disease Incidence ◽  
Plant Diseases ◽  
Stem Rot ◽  
Economic Losses ◽  
Seedling Production ◽  
Seedling Mortality ◽  
Pythium Myriotylum ◽  
Centraalbureau Voor

Pythium species have a wide host range and are important pathogens of many agricultural crops. In Zimbabwe, 15 isolates of Pythium have been obtained from symptomatic tobacco (Nicotiana tabacum) in the new float seedling production system. This production system now accounts for 25 to 30% of the tobacco industry's annual requirement of 975 million seedlings. Disease symptoms are observed usually 5 to 6 weeks after sowing as wilting and yellowing of leaves followed by rotting of the roots, and in severe cases, seedling death. Up to 70% seedling loss has been reported in commercial seedbeds. In a study to fulfill Koch's postulates and to determine the susceptibility of 16 commercially grown tobacco cultivars, seedlings were produced in float trays and inoculated individually with 1 ml of Pythium (Isolate Py 19) spores (1 × 104 CFU/ml) and mycelium pipetted around the base of the stem of each seedling 9 weeks after sowing. First symptoms appeared 7 to 10 days after inoculation as yellowing and wilting of leaves. When seedlings were pulled, the lower portion of the stem and roots were brown and rotted. Seedling mortality averaged 29% and disease incidence was 96 to 100% among cultivars. All 16 tobacco cultivars were susceptible to Pythium root and stem rot and there were no significant (P > 0.05) differences in their susceptibility to the disease. The pathogen was reisolated from the inoculated seedlings. The representative isolate (Py 19) sent to Centraalbureau voor Schimmelcultures, the Netherlands was identified as Pythium myriotylum Drechsler (CBS Accession No. 125021) (2). P. aphanidermatum, causing black stem rot, and P. debaryanum and P. ultimum, responsible for damping-off (3), have been reported in the predominant conventional soil-based tobacco seedling production system, but do not cause economic losses. However, stem and root rot caused by P. myriotylum threaten the float seedling production system in Zimbabwe, although a chemical curative control of the disease has been recommended and is now widely practiced. P. myriotylum has previously been reported in the tobacco float seedling production system in South Carolina (1). To our knowledge, this constitutes the first published report of P. myriotylum on tobacco in Zimbabwe. References: (1) M. G. Anderson et al. Plant Dis. 81:227, 1997. (2) Centraalbureau voor Schimmelcultures. Retrieved from http://www.cbs.knaw.nl , 2010. (3) A. J. Masuka et al. List of Plant Diseases in Zimbabwe. Department of Research and Extension and Tobacco Research Board. Harare, Zimbabwe, 2003.

scholarly journals Effectors of Plant Necrotrophic Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Dandan Shao ◽  
Damon L. Smith ◽  
Mehdi Kabbage ◽  
Mitchell G. Roth
Keyword(s):  
Fungal Pathogens ◽  
Crop Production ◽  
Plant Diseases ◽  
Economic Losses ◽  
Plant Colonization ◽  
Genetic Intervention ◽  
Necrotrophic Fungi ◽  
Plant Pathogen Interaction ◽  
Functional Context ◽  
Necrotrophic Effectors

Plant diseases caused by necrotrophic fungal pathogens result in large economic losses in field crop production worldwide. Effectors are important players of plant-pathogen interaction and deployed by pathogens to facilitate plant colonization and nutrient acquisition. Compared to biotrophic and hemibiotrophic fungal pathogens, effector biology is poorly understood for necrotrophic fungal pathogens. Recent bioinformatics advances have accelerated the prediction and discovery of effectors from necrotrophic fungi, and their functional context is currently being clarified. In this review we examine effectors utilized by necrotrophic fungi and hemibiotrophic fungi in the latter stages of disease development, including plant cell death manipulation. We define “effectors” as secreted proteins and other molecules that affect plant physiology in ways that contribute to disease establishment and progression. Studying and understanding the mechanisms of necrotrophic effectors is critical for identifying avenues of genetic intervention that could lead to improved resistance to these pathogens in plants.

scholarly journals Fight Hard or Die Trying: Current Status of Lipid Signaling during Plant–Pathogen Interaction

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1098
Author(s):  
Sahil Mehta ◽  
Amrita Chakraborty ◽  
Amit Roy ◽  
Indrakant K. Singh ◽  
Archana Singh
Keyword(s):  
Signal Transduction ◽  
Plant Pathogen ◽  
Structural Integrity ◽  
Global Scale ◽  
Plant Diseases ◽  
Current Status ◽  
Economic Losses ◽  
Defense Related Gene ◽  
Plant Pathogen Interaction ◽  
The Impact

Plant diseases pose a substantial threat to food availability, accessibility, and security as they account for economic losses of nearly $300 billion on a global scale. Although various strategies exist to reduce the impact of diseases, they can introduce harmful chemicals to the food chain and have an impact on the environment. Therefore, it is necessary to understand and exploit the plants’ immune systems to control the spread of pathogens and enable sustainable agriculture. Recently, growing pieces of evidence suggest a functional myriad of lipids to be involved in providing structural integrity, intracellular and extracellular signal transduction mediators to substantial cross-kingdom cell signaling at the host–pathogen interface. Furthermore, some pathogens recognize or exchange plant lipid-derived signals to identify an appropriate host or development, whereas others activate defense-related gene expression. Typically, the membrane serves as a reservoir of lipids. The set of lipids involved in plant–pathogen interaction includes fatty acids, oxylipins, phospholipids, glycolipids, glycerolipids, sphingolipids, and sterols. Overall, lipid signals influence plant–pathogen interactions at various levels ranging from the communication of virulence factors to the activation and implementation of host plant immune defenses. The current review aims to summarize the progress made in recent years regarding the involvement of lipids in plant–pathogen interaction and their crucial role in signal transduction.

Synthesis and Antifungal Activities of Drimane-Amide Derivatives from Sclareol

2018 ◽  
Vol 21 (7) ◽  
pp. 501-509 ◽  
Author(s):  
Miaofeng Ma ◽  
Jili Feng ◽  
Dezhi Wang ◽  
Shu-Wei Chen ◽  
Hui Xu
Keyword(s):  
Antifungal Activity ◽  
Fungal Pathogens ◽  
Antifungal Agents ◽  
Control Plant ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
Economic Losses ◽  
Mycelium Growth ◽  
Amide Derivatives

Aim and Objective: Plant diseases are caused by fungal pathogens lead to severe economic losses in many agriculture crops. And the increasing resistance of many fungi to commonly used antifungal agents necessitates the discovery and development of new fungicides. So this study was focused on synthesizing novel skeleton compounds to effectively control plant diseases. Materials and Methods: A series of drimane-amide derivatives were designed, synthesized by aminolysis reaction of amine with intermediate sclareolide which was prepared from sclareol. The structures of all the synthesized compounds were confirmed using 1H NMR, 13C NMR, and HRMS (ESI) spectroscopic data. Their in vitro antifungal activity were preliminarily evaluated by using the mycelium growth rate method against five phytopathogenic fungi: Botrytis cinerea, Glomerella cingulata, Alternaria alternate, Alternaria brassicae, and Fusarium graminearum. Results: 23 target compounds were successfully obtained in yields of 52-95%. Compounds A2 and A3 displayed favorable inhibitory potency against B. cinerea, G. cingulata and A. brassicae with IC50 values ranging from 3.18 to 10.48 µg/mL. These two compounds displayed higher fungicidal activity than sclareol against all the tested phytopathogenic fungi, and were more effective than the positive control thiabendazole against A. alternate and A. brassicae. The structure-activity relationship studies of compounds A1-10 indicated that both the position and type of substituent on the phenyl ring had significant effects on antifungal activity. Conclusion: The drimane-amide derivatives A2 and A3 were the most promising derivatives and should be selected as new templates for the potential antifungal agents.

scholarly journals Fusarium: a ubiquitous fungus of global significance

2012 ◽  
Vol 33 (1) ◽  
pp. 22 ◽  
Author(s):  
LW Burgess ◽  
WL Bryden
Keyword(s):  
Plant Pathogens ◽  
Disease Incidence ◽  
Farming Systems ◽  
Plant Diseases ◽  
Natural Ecosystems ◽  
Fungal Plant Pathogens ◽  
Wide Range ◽  
Socio Economic Impact ◽  
Key Aspects ◽  
The Impact

Fusarium is one of the most economically important genera of fungal plant pathogens, causing significant crop losses and contamination of grain by mycotoxins on a global basis. Some species also cause infections (mycoses) of humans and other animals. Fusarium includes many species, a significant number of which cause a wide range of plant diseases that affect many crops including major food and fibre crops such as wheat, barley, maize, bananas and cotton, often with devastating socio-economic impact. The diseases are often insidious and extremely difficult to control. Its success as a plant pathogen can be attributed to wide host ranges, endophytic infection, and varied modes of survival and dispersal. Representatives occur in virtually all bioclimatic regions of the world in agricultural and natural ecosystems. In this article we present a summary of the key aspects of the biology and morphology of Fusarium and then briefly discuss several plant diseases to illustrate the diverse nature and devastating effects of these fungi, their mycotoxins, the impact of no-till farming systems on disease incidence, and the poorly understood but key role of endophytic colonisation in the disease cycle. Inevitably, the coverage is selective but it indicates the potential global impact of this fungal genus on plant disease and food security.

scholarly journals Molecular Detection of Fusarium oxysporum f. sp. Cubense Race TR4 Infecting Banana Groups in Indo-Gangetic Plains of India

2020 ◽  
pp. 136-148
Author(s):  
Debashis Rana ◽  
Ankit Kumar Ghorai ◽  
Krishnendu Pramanik ◽  
Arpita Das ◽  
Joydeep Banerjee ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Molecular Detection ◽  
Disease Incidence ◽  
Intergenic Spacer ◽  
Asia Pacific ◽  
Economic Losses ◽  
Pathogenicity Test ◽  
Banana Production ◽  
Close Relationship ◽  
The Impact

Panama wilt or Fusarium wilt incited by Fusarium oxysporum f. sp. cubense (Foc) is a major threat for banana cultivation and impacting symbolic economic losses worldwide. Previously Foc race 1 and race 2 was detected in India which eventually spread monoculture of ‘Cavendish’ bananas resistant against these two races. Later on, another new race TR4 of Foc was detected to be incited in ‘Cavendish’ group of banana raised an alarming situation to the global banana industry. In the present study detailed survey was conducted in popular banana growing districts of West Bengal, India for visualizing the impact of disease incidence as well as collection of isolates from infected suckers and rhizomes of ‘Cavendish’ banana with an aim to develop a rapid detection technique for apprehending the presence of Foc TR4 race at early infection stages. Methods comprised of field survey followed by isolation of pathogen, test of pathogenicity and further molecular detection through Foc TR4 specific primers. Results revealed that the colonies formed on the potato dextrose agar (PDA) medium exhibited typical characteristic of Foc. Pathogenicity test conducted by considering healthy plantlet of ‘Grand Naine’ also detected characteristic symptom of Foc. Additionally, PCR assay using specific markers followed by sequencing of 28S-18S ribosomal RNA intergenic spacer spacer (IGS) confirmed the presence of this isolate in the infected samples. Phylogenetic evolution assays revealed a very close relationship of the Foc TR4 strains of India with Asia-Pacific isolates of Foc TR4. This study advocated the urgency of prevention of introduction of Foc TR4 into disease-free areas in the banana growing districts of India for maintaining sustainable banana production.

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