scholarly journals Survival of Botrytis cinerea as mycelium in rose crop debris and as sclerotia in soil

2005 ◽  
Vol 30 (5) ◽  
pp. 516-521 ◽  
Author(s):  
Alderi E Araújo ◽  
Luiz A Maffia ◽  
Eduardo S. G Mizubuti ◽  
Acelino C Alfenas ◽  
Guy de Capdeville ◽  
...  

Botrytis blight caused by Botrytis cinerea is an important disease of rose (Rosa hybrida) grown in greenhouses in Brazil. As little is known regarding the disease epidemiology under greenhouse conditions, pathogen survival in crop debris and as sclerotia was evaluated. Polyethylene bags with petals, leaves, or stem sections artificially infected with B. cinerea were mixed with crop debris in rose beds, in a commercial plastic greenhouse. High percentage of plant parts with sporulation was detected until 60 days, then sporulation decreased on petals after 120 days, and sharply decreased on stems or leaves after 90 days. Sporulation on petals continued for 360 days, but was not observed on stems after 150 days or leaves after 240 days. Although the fungus survived longer on petals, stems and leaves are also important inoculum sources because high amounts of both are deposited on beds during cultivation. Survival of sclerotia produced on PDA was also quantified. Sclerotia germination was greater than 75% in the initial 210 days and 50% until 360 days. Sclerotia weight gradually declined but they remained viable for 360 days. Sclerotia were produced on the buried petals, mainly after 90 days of burial, but not on leaves or stems. Germination of these sclerotia gradually decreased after 120 days, but lasted until 360 days. Higher weight loss and lower viability were observed on sclerotia produced on petals than on sclerotia produced in vitro

2019 ◽  
Vol 8 (1) ◽  
pp. 65 ◽  
Author(s):  
Lorena Barra-Bucarei ◽  
Andrés France Iglesias ◽  
Macarena Gerding González ◽  
Gonzalo Silva Aguayo ◽  
Jorge Carrasco-Fernández ◽  
...  

Botrytis cinerea causes substantial losses in tomato and chili pepper crops worldwide. Endophytes have shown the potential for the biological control of diseases. The colonization ability of native endophyte strains of Beauveria bassiana and their antifungal effect against B. cinerea were evaluated in Solanaceae crops. Root drenching with B. bassiana was applied, and endophytic colonization capacity in roots, stems, and leaves was determined. The antagonistic activity was evaluated using in vitro dual culture and also plants by drenching the endophyte on the root and by pathogen inoculation in the leaves. Ten native strains were endophytes of tomato, and eight were endophytes of chili pepper. All strains showed significant in vitro antagonism against B. cinerea (30–36%). A high antifungal effect was observed, and strains RGM547 and RGM644 showed the lowest percentage of the surface affected by the pathogen. Native strains of B. bassiana colonized tomato and chili pepper tissues and provided important levels of antagonism against B. cinerea.


Plant Disease ◽  
2021 ◽  
Author(s):  
Juliana Silveira Baggio ◽  
Marcus Vinicius Marin ◽  
Natalia A. Peres

Phytophthora crown rot, caused mainly by Phytophthora cactorum, and also by the recently reported P. nicotianae, is an important disease in the Florida strawberry annual production system. Mefenoxam is the most effective and widely used fungicide to manage this disease. However, due to pathogen resistance, alternatives to chemical control are needed. Phytophthora spp. were rarely recovered during the summer from soil of commercial farms where the disease was observed during the season. In a more detailed survey on research plots, neither of the two species was recovered one month after the crop was terminated and water was shut off. Therefore, Phytophthora spp. does not seem to survive in the soil over summer in Florida. In a field trial, asymptomatic nursery transplants harboring quiescent infections were confirmed as the major source of inoculum for these pathogens in Florida. Heat treatment of P. cactorum zoospores at 44oC for as little as 5 min was effective in inhibiting germination and colony formation; however, oospore germination was not inhibited by any of the tested temperatures in vitro. In the field, thermotherapy treatment of inoculated plants was shown to have great potential to serve as a non-chemical approach for managing Phytophthora crown rot in production fields and reducing mefenoxam-resistant populations in nursery transplants.


2002 ◽  
Vol 2 (1) ◽  
pp. 26-31
Author(s):  
Cipta Ginting ◽  
Abdul Gafur ◽  
Rusdi Evizal

Some results of inoculations on coffee leaf disks with Hemileia vastatrix.  Leaf rust caused by Hemileia vastatrix B. et Br. is the most important disease on coffee worldwide.  The obligate nature of H. vastatrix limits research on the disease when inoculation or pathogen growth in laboratory is required.  Inoculation on detached plant parts such as leaf disks may become an alternative to solve the problems.  In this study, the procedure was tested using three coffee varieties (Kartika 1,  USDA, and Robusta) as inoculum sources, leaves of different age, and different uredospore concentrations (4 x 103, 4 x 104, and 4 x 105 uredospores per ml suspension).  The study was done in Laboratory of Plant Disease at University of Lampung from May to December 2001.  Uredospores developed on leaves under field condition were used as inoculum.  The uredospores were taken with sterilized scalpel and placed in sterilized distilled water.  Before doing the experiments, the uredospores were measured using microscope equipped with a micrometer.  The concentration of uredospore suspensions were prepared using hemacytometer.  Leaf disks made with diameter of 2 cm were used in all inoculations.  The results showed that the size of the uredospores varied greatly.  The variation occurred not only among uredospores taken from different lesions  or leaves but also among those taken from the same lesions.  The size of almost all uredospores was the same as that reported in the literature.  Uredospores taken from Kartika (but not from two other varieties) incited disease development and produced symptoms on leaf disks which were made from Kartika coffee.  The age of leaves used to make leaf disks did not influence disease incidence.  Uredospores concentration influenced ( = 0.05) disease incidence on leaf disks with higher concentration caused higher disease incidence .


2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.


2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Monika Oláhová ◽  
Bradley Peter ◽  
Zsolt Szilagyi ◽  
Hector Diaz-Maldonado ◽  
Meenakshi Singh ◽  
...  

AbstractWhile >300 disease-causing variants have been identified in the mitochondrial DNA (mtDNA) polymerase γ, no mitochondrial phenotypes have been associated with POLRMT, the RNA polymerase responsible for transcription of the mitochondrial genome. Here, we characterise the clinical and molecular nature of POLRMT variants in eight individuals from seven unrelated families. Patients present with global developmental delay, hypotonia, short stature, and speech/intellectual disability in childhood; one subject displayed an indolent progressive external ophthalmoplegia phenotype. Massive parallel sequencing of all subjects identifies recessive and dominant variants in the POLRMT gene. Patient fibroblasts have a defect in mitochondrial mRNA synthesis, but no mtDNA deletions or copy number abnormalities. The in vitro characterisation of the recombinant POLRMT mutants reveals variable, but deleterious effects on mitochondrial transcription. Together, our in vivo and in vitro functional studies of POLRMT variants establish defective mitochondrial transcription as an important disease mechanism.


Author(s):  
Anurag Shetty ◽  
Girisha Balaraju ◽  
Shiran Shetty ◽  
Cannanore Ganesh Pai

Abstract Background Clinical features are of modest benefit in determining the etiology of dyspepsia. Dyspeptic patients with alarm features are suspected to have malignancy; but the proportions of patients and true cutoff values of various quantitative parameters in predicting malignancy are explored to a lesser extent. Methods This is a prospective observational study of consecutive patients undergoing esophagogastroduodenoscopy (EGD) for dyspeptic symptoms. Patients’ alarm features and clinical details were recorded in a predesigned questionnaire. The diagnostic accuracy of alarm features in predicting malignancy was studied. Results Nine hundred patients, 678 (75.3%) males, with a mean (standard deviation [SD]) age of 44.6 (13.54) years were enrolled. Commonest indication for EGD was epigastric pain in 614 (68.2%) patients. Dyspepsia was functional in 311 (34.6%) patients. EGD revealed benign lesions in 340 (37.8%) and malignancy in 50 (5.5%) patients. Among the malignant lesions, gastric malignancy was present in 28 (56%) and esophageal malignancy in 20 (40%) patients. Alarm features were present in 206 (22.9%), out of which malignant lesions were seen in 46 (22.3%) patients. Altogether, the alarm features had a sensitivity of 92% and specificity of 81.2% for predicting malignancy. The sensitivity and specificity for weight loss were 76% and 90.8%, while that of abdominal mass were 10% and 99.9% respectively. Based on receiver operating characteristic curve, the optimal age for screening of malignancy was 46.5 years in this population. Conclusions Patients of age group 40 to 49 years with dyspeptic alarm symptoms (predominant weight loss) need prompt endoscopy to screen for malignancy. The alarm features are inexpensive screening tools, found to be useful in India, and should be utilized in countries with similar healthcare conditions and disease epidemiology.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 975
Author(s):  
Ye-Eun Park ◽  
Chang-Ha Park ◽  
Hyeon-Ji Yeo ◽  
Yong-Suk Chung ◽  
Sang-Un Park

Peanut (Arachis hypogaea) is a crop that can produce resveratrol, a compound with various biological properties, such as those that exert antioxidant, anticancer, and anti-inflammatory effects. In this study, trans-resveratrol was detected in the roots, leaves, and stems of tan and purple seed coat peanuts (Arachis hypogaea) cultivated in a growth chamber. Both cultivars showed higher levels of resveratrol in the roots than the other plant parts. Thus, both cultivars were inoculated with Agrobacterium rhizogenes, in vitro, to promote hairy root development, thereby producing enhanced levels of t-resveratrol. After 1 month of culture, hairy roots from the two cultivars showed higher levels of fresh weight than those of seedling roots. Furthermore, both cultivars contained higher t-resveratrol levels than those of their seedling roots (6.88 ± 0.21 mg/g and 28.07 ± 0.46 mg/g, respectively); however, purple seed coat peanut hairy roots contained higher t-resveratrol levels than those of tan seed coat peanut hairy roots, ranging from 70.16 to 166.76 mg/g and from 46.61 to 54.31 mg/g, respectively. The findings of this study indicate that peanut hairy roots could be a good source for t-resveratrol production due to their rapid growth, high biomass, and substantial amount of resveratrol.


2021 ◽  
Vol 8 (02) ◽  
pp. e62-e68
Author(s):  
Jeeta Sarkar ◽  
Nirmalya Banerjee

AbstractSteroid alkaloid solasodine is a nitrogen analogue of diosgenin and has great importance in the production of steroidal medicines. Solanum erianthum D. Don (Solanaceae) is a good source of solasodine. The aim of this study was to evaluate the effect of different cytokinins on the production of secondary metabolites, especially solasodine in the in vitro culture of S. erianthum. For solasodine estimation, field-grown plant parts and in vitro tissues were extracted thrice and subjected to high-performance liquid Chromatography. Quantitative analysis of different secondary metabolites showed that the amount was higher in the in vitro regenerated plantlets compared to callus and field-grown plants. The present study critically evaluates the effect of the type of cytokinin used in the culture medium on solasodine accumulation in regenerated plants. The highest solasodine content (46.78±3.23 mg g-1) was recorded in leaf extracts of the in vitro grown plantlets in the presence of 6-γ,γ-dimethylallylamino purine in the culture medium and the content was 3.8-fold higher compared to the mother plant.


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