Studies in vitro and in vivo with powdery mildew fungicides

1973 ◽  
Vol 73 (3) ◽  
pp. 299-306 ◽  
Author(s):  
D. R. CLIFFORD ◽  
E. C. HISLOP
Keyword(s):  
Powdery Mildew

scholarly journals Effect of Water Stress on Reproduction and Colonization of Podosphaera aphanis of Strawberry

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2973-2978
Author(s):  
Franca G. Rossi ◽  
Belachew Asalf ◽  
Chloe Grieu ◽  
Rodrigo B. Onofre ◽  
Natalia A. Peres ◽  
...  
Keyword(s):  
Water Stress ◽  
Powdery Mildew ◽  
Plant Stress ◽  
Leaf Curling ◽  
In Vivo Experiments ◽  
Powdery Mildews ◽  
Leaf Surfaces ◽  
Mild Water Stress

In a number of pathosystems involving the powdery mildews (Erysiphales), plant stress is associated with decreased disease susceptibility and is detrimental to pathogen growth and reproduction. However, in strawberry, anecdotal observations associate severe powdery mildew (Podosphaera aphanis) with water stress. In a 2017 survey of 42 strawberry growers in Norway and California, 40 growers agreed with a statement that water-stressed strawberry plants were more susceptible to powdery mildew compared with nonstressed plants. In repeated in vitro and in vivo experiments, we found that water stress was consistently and significantly unfavorable to conidial germination, infection, and increases in disease severity. Deleterious effects on the pathogen were observed from both preinoculation and postinoculation water stress in the host. Soil moisture content in the range from 0 to 50% was correlated (R2 = 0.897) with germinability of conidia harvested from extant colonies that developed on plants growing at different levels of water stress. These studies confirm that P. aphanis fits the norm for biotrophic powdery mildews and hosts under stress. Mild water stress, compared with a state of optimal hydration, is likely to decrease rather than increase susceptibility of strawberry to P. aphanis. We believe it is possible that foliar symptoms of leaf curling due to diffuse and inconspicuous infection of the lower leaf surfaces by P. aphanis could easily be mistakenly attributed to water stress, which we observed as having a nearly identical leaf curling symptom in strawberry.

scholarly journals Management of powdery mildew of cluster bean through fungi toxicants

2020 ◽  
Vol 13 (2) ◽  
pp. 207-210
Author(s):  
Arun R. Sataraddi ◽  
Jitendra Kumar S. Hilli
Keyword(s):  
Powdery Mildew ◽  
Field Trials ◽  
Complete Inhibition ◽  
Systemic Fungicides ◽  
Cluster Bean ◽  
Aerial Parts ◽  
Cent Concentration ◽  
Potential Methods

Leveillula taurica causes severe powdery mildew on all aerial parts of cluster bean plant. The objective of the present work was to identify potential methods for managing cluster bean powdery mildew through fungicides. Field trials were conducted during Kharif 2019 and 2020 to evaluate the efficacy fungicides. Nine systemic fungicides were tested both under in-vitro and in-vivo conditions against cluster bean powdery mildew disease. In vitro evaluation of fungicides revealed that complete inhibition of conidial germination was observed in all systemic fungicides at 0.1 per cent concentration. However, under field conditions, penconazole at 0.05 per cent was found to be best fungicide which recorded least incidence 3.66 per cent followed by hexaconazole (5.83%) and propiconazole (6.83%).

In vitro and in vivo evaluation of microbial-enriched compost tea on the development of powdery mildew on melon

BioControl ◽  
2012 ◽  
Vol 57 (6) ◽  
pp. 827-836 ◽  
Author(s):  
Yuvarani Naidu ◽  
Sariah Meon ◽  
Yasmeen Siddiqui
Keyword(s):  
Powdery Mildew ◽  
Compost Tea ◽  
In Vivo Evaluation

scholarly journals Some results of the study of alfalfa and meadow clover samples created by biotechnology methods

2021 ◽  
Vol 901 (1) ◽  
pp. 012027
Author(s):  
M N Agafodorova ◽  
P D Solozhentsev ◽  
L A Solodkaya ◽  
L I Lapotyshkina ◽  
I A Klimenko ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Biological Traits ◽  
Tolerant Plants ◽  
Acid Tolerant ◽  
Fusarium Pathogens ◽  
Genetic Level ◽  
Pcr Method ◽  
Gamete Selection

Abstract The conditions for creating alfalfa samples MN-2 (from the Selena variety) and P-67 (from the Lugovaya variety) with increased resistance to Fusarium pathogens using the method of gamete selection are described. The method is based on the selection of gametes in vivo under the influence of a selective factor (culture filtrate) introduced into the generative organs at the early stages of their development using vacuum infiltration. The method was developed in the biotechnology department of the V.N. V.R. Williams. The accessions are included in the breeding process and are currently the accessory varieties. In order to identify differences at the genetic level between the created varieties and the original forms, a comparative analysis was carried out using 2 types of molecular markers based on the PCR method. DNA polymorphism was detected using SRAP primers, which may indicate a change in the structure of genes associated with economic and biological traits. Research is ongoing. When growing under the conditions of a selection and greenhouse complex of acid-tolerant plants of meadow clover, created using cellular technologies in vitro, the infestation by powdery mildew of 120 acid-tolerant plants was studied. No signs of damage were found in 10% of plants. The largest number of affected plants (36.7%) had a score of 3. It was found that a high infestation with powdery mildew (scores 4 and 5) significantly reduces the number of inflorescences in the bush to 83.4 and 75.7%, respectively. Therefore, in further studies to create a population of acid-tolerant plants, the genotypes of meadow clover were used without signs and with a low score of powdery mildew damage.

scholarly journals Biological Control of Celery Powdery Mildew Disease Caused by Erysiphe heraclei DC In Vitro and In Vivo Conditions

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2342
Author(s):  
Hamada F. A. Ahmed ◽  
Mahmoud F. Seleiman ◽  
Adel M. Al-Saif ◽  
Maha A. Alshiekheid ◽  
Martin L. Battaglia ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Germ Tube ◽  
The Other ◽  
Biocontrol Agents ◽  
Tube Length ◽  
Conidia Germination ◽  
Germ Tube Length

The present study aimed to investigate the potentiality of certain biocontrol agents, namely Bacillus subtilis, B. pumilus, B. megaterium, Pseudomonas fluorescens, Serratia marcescens, Trichoderma album, T. harzianum and T. viride, as well as the synthetic fungicide difenoconazole to control celery powdery mildew caused by Erysiphe heraclei DC, in vitro (against conidia germination and germ tube length of E. heraclei) and in vivo (against disease severity and AUDPC). In vitro, it was found that the antifungal activity of the tested biocontrol agents significantly reduced the germination percentage of the conidia and germ tube length of the pathogen. The reduction in conidia germination ranged between 88.2% and 59.6% as a result of the treatment with B. subtilis and T. album, respectively compared with 97.1% by the synthetic fungicide difenoconazole. Moreover, the fungicide achieved the highest reduction in germ tube length (92.5%) followed by B. megaterium (82.0%), while T. album was the least effective (62.8%). Spraying celery plants with the tested biocontrol agents in the greenhouse significantly reduced powdery mildew severity, as well as the area under the disease progress curve (AUDPC), after 7, 14, 21 and 28 days of application. In this regard, B. subtilis was the most efficient followed by B. pumilus, S. marcescens and B. megaterium, with 80.1, 74.4, 73.2 and 70.5% reductions in disease severity, respectively. In AUDPC, reductions of those microorganisms were 285.3, 380.9, 396.7 and 431.8, respectively, compared to 1539.1 in the control treatment. On the other hand, the fungicide difenoconazole achieved maximum efficacy in reducing disease severity (84.7%) and lowest AUDPC (219.3) compared to the other treatments. In the field, all the applied biocontrol agents showed high efficiency in suppressing powdery mildew on celery plants, with a significant improvement in growth and yield characteristics. In addition, they caused an increase in the concentration of leaf pigments, and the activities of defense-related enzymes such as peroxidase (PO) and polyphenol oxidase (PPO) and total phenol content (TPC). In conclusion, the results showed the possibility of using tested biocontrol agents as eco-friendly alternatives to protect celery plants against powdery mildew.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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