inoculation techniques
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2022 ◽  
pp. 193-213
Author(s):  
Florin Gaiseanu

This chapter described the intimate processes of the informational system of the human body and cells and their effect on the mind in order to understand how information is received/operated and integrated in the genetic structure of the organism by epigenetic mechanisms. Individual education/learning are the basic processes allowing the knowledge/judgement of mediated reality, and for the formation of decision criteria, beliefs, and mentality. The contributive role of media in education/behavior is highlighted, revealing the positive/negative effects of the persuasive messages in interaction with individual/collective beliefs and mentality. The inoculation techniques applied in various fields of media are discussed from the informational perspective, emphasizing the implication of the cognitive centers on such processes. Big data analysis and predictive conclusions on the social effects are used nowadays as feedback support, helping the optimization of the relation between audience and media products.


Author(s):  
James C. Fulton ◽  
Matthew A. Cullen ◽  
Kristin Beckham ◽  
Tatiana Sanchez ◽  
Zhuxuan Xu ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Eduardo Bernal ◽  
Loïc Deblais ◽  
Gireesh Rajashekara ◽  
David M. Francis

Imaging technology can provide insight into biological processes governing plant-pathogen interactions. We created and used a bioluminescent strain of Xanthomonas hortorum pv. gardneri (Xgb) to quantify infection processes in plants using tomato as a model. An X. hortorum pv. gardneri is one of the four Xanthomonas species that causes bacterial spots in tomatoes. We used Xgb to quantify bacterial growth in planta, to assess disease severity in resistant and susceptible tomato lines, and to observe infection routes in leaves. A positive and significant linear correlation r (67) = 0.57, p ≤ 0.0001 was observed between bioluminescence signals emitted by Xgb in planta and bacterial populations determined through dilution plating. Based on bioluminescence imaging, resistant and susceptible tomato lines had significantly different average radiances. In addition, there was a positive and significant correlation r = 0.45, p = 0.024 between X. hortorum pv. gardneri-inoculated tomato lines evaluated by bioluminescence imaging and tomatoes rated in the field using the Horsfall-Barrat Scale. Heritability was calculated to compare the genetic variance for disease severity using bioluminescence imaging and classical field ratings. The genetic variances were 25 and 63% for bioluminescence imaging and field ratings, respectively. The disadvantage of lower heritability attained by bioluminescence imaging may be offset by the ability to complete germplasm evaluation experiments within 30 days rather than 90–120 days in field trials. We further explored X. hortorum pv. gardneri infection routes on leaves using spray and dip inoculation techniques. Patterns of bioluminescence demonstrated that the inoculation technique affected the distribution of bacteria, an observation verified using scanning electron microscopy (SEM). We found significant non-random distributions of X. hortorum pv. gardneri on leaf surfaces with the method of inoculation affecting bacterial distribution on leaf surfaces at 4 h postinoculation (hpi). At 18 hpi, regardless of inoculation method, X. hortorum pv. gardneri localized on leaf edges near hydathodes based on bioluminescence imaging and confirmed by electron microscopy. These findings demonstrated the utility of bioluminescent X. hortorum pv. gardneri to estimate bacterial populations in planta, to select for resistant germplasm, and to detect likely points of infection.


Author(s):  
Donald Schaffner ◽  
Marina Girbal ◽  
Laura K. Strawn ◽  
Claire M. Murphy

L. monocytogenes causes relatively few outbreaks linked to whole fresh produce but triggers recalls each year in the US. There are limited data on the influence of wet vs. dry methods on pathogen growth on whole produce. A cocktail of five L. monocytogenes strains that included clinical, food, or environmental isolates associated with foodborne outbreaks and recalls was used. Cultures were combined to target a final wet inoculum concentration of 4-5 log CFU/mL. The dry inoculum was prepared by mixing wet inoculum with 100 g of sterile sand and drying for 24 h. Produce investigated belonged to major commodity families: Ericaceae (blackberry, raspberry, and blueberry), Rutaceae (lemon and mandarin orange), Roseaceae (sweet cherry), Solanaceae (tomato), Brassaceae (cauliflower and broccoli) and Apiaceae (carrot). Intact, whole inoculated fruit and vegetable commodities were incubated at 2, 12, 22 and 35±2°C. Commodities were sampled for up to 28 days, and the experiment was replicated 6 times. The average maximum growth increase was obtained by measuring the maximum absolute increase for each replicate within a specific commodity, temperature, and inoculation method. Data for each commodity, replicate and temperature was used to create primary growth or survival models, describing the lag phase and growth or shoulder and decline as a function of time. Use of a liquid inoculum (vs. dry inoculum) resulted in markedly increased L. monocytogenes growth rate and growth magnitude on whole produce surfaces. This difference was highly influenced by temperature with a greater effect seen with more commodities at higher temperatures (22 and 35°C), versus lower temperatures (2 and 12 °C). These findings need to be explored for other commodities and pathogens. The degree to which wet or dry inoculation techniques more realistically mimic contamination conditions throughout the supply chain (e.g., production, harvest, post-harvest, transportation, or retail) should be investigated.


Author(s):  
Manju Kumari ◽  
Om Prakash Sharma ◽  
B.D.S. Nathawat

Background: Lentil is a vital nutritional source of protein in several parts of the world including India. The crop is susceptible to wilt which is a devastating soil-borne disease induced by the fungus Fusarium oxysporum f. sp. lentis. Insight of the potential threat Fusarium wilt can pose to lentils, a present study done on pathogenicity, host range and influence of temperature, humidity and pH levels on the growth of F. oxysporum f. sp. lentis.Methods: Ten isolates FOL-01 to FOL-10 of F. oxysporum f. sp. lentis (Fol) were isolated from wilted lentil plants that collected from different major lentil growing parts of Rajasthan. During 2017-18 a pathogenicity test was tested in pot house condition by seed and soil inoculation techniques for all isolates and epidomological factors evaluated in vitro conditions.Result: Results indicated that the Fol isolates represent a single race but differ in their aggressiveness on the susceptible cultivar L9-12. Pathogenicity test revealed clearly that Fol was associated with wilt symptoms and were pathogenic to lentil plants. A maximum percent disease incidence of 70.00 was showed by isolate FOL-02 in soil inoculation technique. In the morphological and cultural characterization, all the ten isolates showed various character in conidial frequency, colony color and growth pattern. Twenty plant species were tested to know the host range of Fol, out of these lentil, chickpea and pea show positive reaction with the pathogen. The influence of temperature, relative humidity and pH on the growth and sporulation of Fol was studied under in vitro conditions. Maximum mycelial growth and sporulation of the Fol were observed at 30°C, 6.0 pH and 60% relative humidity.


2021 ◽  
Vol 10 (3) ◽  
pp. 758-759
Author(s):  
Shashank Mishra ◽  
Prashant Mishra ◽  
Ajay Kumar Mishra ◽  
Jaskaran Singh

2021 ◽  
Vol 9 (2) ◽  
pp. 219
Author(s):  
Ethan M. Doherty ◽  
Pasco B. Avery ◽  
Emily B. Duren ◽  
Liliana M. Cano ◽  
Lorenzo Rossi

Entomopathogenic fungi can be a useful resource for controlling insect vectors of citrus plant pathogens, such as the Asian citrus psyllid (Diaphorina citri) associated with huanglongbing or the citrus root weevil (Diaprepes abbreviatus) associated with the spread of Phytophtora spp. In this study, Cordyceps fumosorosea (Cfr) was investigated in planta as a potential endophytic entomopathogenic fungus and various inoculation techniques were used to determine if it would colonize the Carrizo citrange (Citrus × insitorum) seeds and plants. The four inoculation methodologies evaluated were seed soaking, stem injection, foliar spray, and soil drench. Seed immersion trials demonstrated that the roots of the Carrizo citrange plant can be inoculated successfully with Cfr. Stem injection, foliar spray, and soil drench also provided successful inoculation of Cfr. However, this fungus was only endophytic in the plant stem. Sand cores indicated that Cfr moved down through the sand column and was able to inoculate the roots. Given the prevalence of Cfr in the soil during the drench experiment, and that the fungus was able to colonize Carrizo citrange roots through seed immersion, this finding provides evidence of the potential endophytism of this fungus when applied to citrus plant species.


2020 ◽  
pp. 1764-1771
Author(s):  
Romina Priscila Bertani ◽  
Constanza María Joya ◽  
Diego Daniel Henriquez ◽  
Claudia Funes ◽  
Victoria González ◽  
...  

The red stripe disease caused by Acidovorax avenae subsp. avenae in sugarcane, has become a quite relevant issue in Argentina because of its high incidence in the sugarcane growing area. The resistance of host plants is the most promising method for controlling the disease. In that sense, the Estación Experimental Agroindustrial Obispo Colombres (EEAOC) has a Sugarcane Breeding Program, which generates new varieties with higher productivity and good sanitary behavior. The lack of an effective screening technique to select resistant sugarcane genotypes limits the cultivar selection process. To develop a practical and affordable method for achieving the expression of the red stripe disease, three available inoculation techniques were evaluated under controlled conditions over two sugarcane varieties, with a previously adjustment of soil composition and nutrition and relative humidity. They consisted in (i) scrubbing the leaf surface with a cotton ball soaked in the suspension of A. avenae subsp. avenae; and spraying inoculum under two conditions: (ii) leaves pre-treated with a refined sand scarification and (iii) leaves with no scarification. Fifteen plants were inoculated per cultivar and treatment according to a randomized protocol with three replicates and the severity of the disease was evaluated on a scale of 1- 9 according to the International Society of Sugarcane Technologists. The spray inoculation using a bacterial suspension of A. avenae subsp. avenae without abrasives was also field tested. These results contribute to sugarcane breeding programs, providing a tool to assess the resistance to red stripe of their materials, overcoming the lack of bacterial pressure or favorable conditions for the disease.


2020 ◽  
Vol 68 (4) ◽  
Author(s):  
Natalia Allegrucci ◽  
María Silvana Velazquez ◽  
María Leticia Russo ◽  
María Florencia Vianna ◽  
Camila Abarca ◽  
...  

Introduction: Entomopathogenic fungi have been used as biological control agents of insect pests and have demonstrated a promising ability to colonize as endophytes a wide range of plant species. Objective: The aims of this study were to evaluate, in pepper plants, the most effective Beauveria bassiana inoculation techniques. In order to evaluate the presence of natural endophytes and its interaction with B. bassiana. Also to assess the effect of B. bassiana on the aphid Myzus persicae pepper leaf feeding preference and growth. Methods: Three inoculation techniques were evaluated: leaf spraying, seed immersion and root dipping. The pepper plants were inoculated with a conidia suspension adjusted to 1×108 conidia/ml. The presence of B. bassiana in the seedlings was evaluated at 7, 15 and 28 days after inoculation. Results: We found significant statistical differences between inoculation techniques. Foliar spraying showed the highest B. bassiana colonization frequency. The natural endophytes presented higher presence in the treatments in which B. bassiana had a low presence. This might indicate the occurrence of antifungal activity that interferes with the establishment of the entomopathogen in pepper tissues. We did not find statistical differences between inoculated and control pepper leaves with regard to the mortality and reproduction of the aphid pest M. persicae. However, the inoculation with B. bassiana showed a tendency to increase the mortality of adults and to decrease the offspring (nymphs). We did not find significant differences in the feeding preference between inoculated and control leaves, although there was a higher number of individuals on control leaves compared to those inoculated. Conclusions: The strain B. bassiana LPSC 1067 was established effectively as an endophyte in the pepper tissues. The most effective inoculation technique was leaf spraying. We did not find differences of statistical significance with regard to the mortality and reproduction of the aphid pest M. persicae. However, the inoculation with B. bassiana showed a tendency to increase the mortality of adults and to decrease the offspring (nymphs). Future studies evaluating the indirect effects of endophytic entomopathogens on both plants and herbivorous insects are needed to further explore their potential use in the management of insect pests.


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