Adjustment of a rapid method for quantification of Fusarium spp. spore suspensions in plant pathology

Caligiore-Gei, Pablo F.; Valdez, J. G.

doi:10.1016/j.ram.2015.03.002

Cited by 13 publications

(11 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The conidia were dislodged by gently scraping the colony surface with a spatula. The resulting suspension was shaken well and filtered through a sterilized cheesecloth to obtain a pure spore suspension, then spores were adjusted to 10 7 spore mL −1 using a haemocytometer [101,102]. Biocontrol agent bacterial isolates were grown separately in a liquid nutrient broth in 250 mL flasks and kept on an orbital shaker at 150 rpm for 3-4 days.…”

Section: Preparation Of Biocontrol Agent Inoculamentioning

confidence: 99%

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

Ahmed

Seleiman

Al-Saif

et al. 2021

Plants

View full text Add to dashboard Cite

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.

show abstract

Section: Preparation Of Biocontrol Agent Inoculamentioning

confidence: 99%

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

Ahmed

Seleiman

Al-Saif

et al. 2021

Plants

View full text Add to dashboard Cite

show abstract

“…The measurement of conidial concentration of F. oxysporum in tomato and its relation with spectral response in leaves during the incubation period of the disease is a basic requirement to allow comparisons, repetitiveness, and genetic analysis of disease tolerance and standardization of the results in many experiments on controlled and semi-controlled environments (Caligiore-Gei and Valdez, 2015). The inoculum concentration of F. oxysporum influenced the severity of the disease.…”

Section: Discussionmentioning

confidence: 99%

Linking physiological parameters with visible/near-infrared leaf reflectance in the incubation period of vascular wilt disease

Marín-Ortiz

Gutierrez-Toro

Botero-Fernández

et al. 2020

Saudi Journal of Biological Sciences

View full text Add to dashboard Cite

The photosynthetic pigments are mainly responsible for absorbing the light intended to promote photosynthesis on the chloroplast of the leaves. Different studies have related the spectral response in the leaves of plants with the biotic stress generated by pathogens. In general, maximum differences in reflectance have been found in the range of 380–750 nm between plants subjected to biotic stress and healthy plants. In this study, it was possible to characterize and relate the spectral variance in leaves of S. lycopersicum infected with F. oxysporum with this physiological variation and pathogen concentration in tomato plants during the asymptomatic period of vascular wilt. Photosynthetic parameters derived from gaseous exchange analysis in the tomato leaves correlated related with four bands in the visible range (Vis). Additionally, five specific bands also present a high correlation with the increase in the concentration of F. oxysporum conidia measured at the root: 448–523 nm, 624–696 nm, 740–960 nm, 973–976 nm, and 992–995 nm. These wavelengths allowed a 100% correct classification of the plants inoculated with F. oxysporum from the plants subjected to hydric stress and the control plants in the asymptomatic period of the disease. The spectral response to biotic and abiotic stress in the measured Vis/NIR range can be explained by the general tendency to change the concentration of chlorophyll and carotene in tomato leaves. These studies also highlight the importance of the implementation of robust multivariate analysis over the multiple univariate analysis used in the applied biological sciences and specifically in the agricultural sciences. These results demonstrate that specific wavelength responses are due to physiological changes in plants subjected to stress, and can be used in indexes and algorithms applied to the early detection of diseases in plants on different pathosystems.

show abstract

“…Species-dependent standardization processes are not routinely used in microbiology laboratories and are not familiar to lab personnel. Several studies have compared widely used methods such as cell counting by hemocytometer, which is a procedure stipulated in the EUCAST E.DEF9.1 standard ( 5 – 7 ), but few studies have tested photometers as alternatives for hemocytometric and spectrophotometric measurements ( 7 , 8 ).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the Copan ESwab Transport System for Viability of Pathogenic Fungi by Use of a Modification of Clinical and Laboratory Standards Institute Document M40-A2

2018

View full text Add to dashboard Cite

The Copan ESwab system was evaluated for its ability to maintain the viability of pathogenic fungi. Tests followed the Clinical and Laboratory Standards Institute (CLSI) document M40-A2 roll-plate method at room and refrigerator temperatures. A system was devised for standardizing homogeneous inoculum suspensions of variously sized conidia and sporangiospores of filamentous fungi. A total of 19 clinical and reference strains were standardized to a 0.5 McFarland turbidity standard with a simple photometer. Corresponding optical densities were measured with a spectrophotometer. Colony counts equal to or greater than those seen at time zero were obtained for the entire test panel. Results indicate that the Copan ESwab system effectively maintains prevalent opportunistic fungal organisms for at least 48 h.

show abstract

Adjustment of a rapid method for quantification of Fusarium spp. spore suspensions in plant pathology

Cited by 13 publications

References 5 publications

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

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

Linking physiological parameters with visible/near-infrared leaf reflectance in the incubation period of vascular wilt disease

Evaluation of the Copan ESwab Transport System for Viability of Pathogenic Fungi by Use of a Modification of Clinical and Laboratory Standards Institute Document M40-A2

Contact Info

Product

Resources

About