Effect of inoculum concentration, age and degree of susceptibility of the host on bacterial leaf streak development

1977 ◽  
Vol 86 (4) ◽  
pp. 223-227
Author(s):  
C Seshagiri Rao ◽  
S Devadath
Keyword(s):  
Bacterial Leaf Streak ◽  
Inoculum Concentration

scholarly journals Optimization of cultivation conditions for Microcystis aeruginosa for biodiesel production using response surface methodology

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Samar A. El-Mekkawi ◽  
N. N. El-Ibiari ◽  
Ola A. El-Ardy ◽  
Nabil M. Abdelmonem ◽  
Ahmed H. Elahwany ◽  
...  
Keyword(s):  
Response Surface ◽  
Microcystis Aeruginosa ◽  
Biomass Yield ◽  
Bubble Column ◽  
Biodiesel Production ◽  
Cultivation Conditions ◽  
Inoculum Concentration ◽  
Initial Inoculum ◽  
High Lipid ◽  
Oil Concentration

Abstract Background Biodiesel is expected to play a key role in the development of a sustainable, economical, and environmentally safe source of energy. The third generation of biodiesel is derived from microalgae and cyanobacteria that have sufficient amount of oil. The optimization of biomass and oil content in biodiesel production based on algal cultivation relies upon several factors. The present experimental work aims at optimizing some of the cultivation conditions to obtain maximum oil and biomass yield and create a prediction model that describe the effect of the initial inoculum concentration, and irradiance on the biomass yield and oil concentration were designed using Design Expert 6.0.8. Results The results revealed that the optimum surface-to-volume ratio for the airlift bubble column photobioreactor was 0.9, and the most applicable model for describing Microcystis aeruginosa growth was the hyperbolic tangent model with a model constant value of 1.294 mg·L− 1·d− 1/μmol·m− 2·s− 1. The optimum cultivation conditions were 81 μmol·m− 2·s− 1 irradiance and 67 mg·L− 1 initial inoculum concentration, and these conditions achieved a biomass yield of 163 mg·L− 1·d− 1 and an oil concentration of 143 mg·L− 1. Conclusions This work focused on the cultivation of microalgae in closed systems. Cyanobacteria as M. aeruginosa has high lipid content, and high lipid productivity makes it suitable as a lipid feed stock for biodiesel production. The response surface method was the most suitable route to study the simultaneous influence of irradiance and initial inoculum concentration through statistical methods as well as to establish a model for predicting the biomass yield and oil concentration of M. aeruginosa.

scholarly journals Development of a Protocol and a Diagrammatic Scale for Quantification of Bacterial Leaf Streak Disease on Young Plants of Maize

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2921-2927
Author(s):  
Renata Rodrigues Robaina ◽  
Talita Vigo Longhi ◽  
Douglas Mariani Zeffa ◽  
Leandro Simões Azeredo Gonçalves ◽  
Rui Pereira Leite
Keyword(s):  
Disease Incidence ◽  
The United States ◽  
Bacterial Suspension ◽  
Bacterial Leaf Streak ◽  
Experimental Conditions ◽  
Maize Production ◽  
Maize Hybrids ◽  
Controlled Conditions ◽  
Maize Plants ◽  
Diagrammatic Scale

Bacterial leaf streak (BLS), caused Xanthomonas vasicola pv. vasculorum (Xvv), has become a major concern for maize production, mainly in the United States and South America. Therefore, this study aimed to establish a protocol for Xvv inoculation in young maize plants under controlled conditions and to develop and validate a diagrammatic scale for evaluation of maize hybrids in regard to BLS resistance. The study was carried out in three steps: the establishment of a protocol for inoculation of Xvv in young maize plants under controlled conditions; the development and validation of a diagrammatic scale for BLS severity evaluation; and the screening for BLS resistance of 45 hybrids using the proposed protocol for bacterial inoculation and the diagrammatic scale developed in this study. Besides reproducing a more natural Xvv infection, the bacterial suspension spraying without injury inoculation method induced higher disease incidence and severity, as well as reproducibility of results under the experimental conditions established in this study. The proposed diagrammatic scale allowed evaluating BLS severity with up to 97.49% of the leaf area affected by the disease. Further, the use of the diagrammatic scale resulted in an increase of accuracy from 0.909 up to 0.992. The reaction of 45 maize hybrids to BLS allowed establishing six major groups of susceptibility to the disease. The most resistant maize hybrids to BLS formed a group of 13 hybrids, with disease severity below 5%.

scholarly journals Efficacy and Application Strategies for Propiconazole as a New Postharvest Fungicide for Managing Sour Rot and Green Mold of Citrus Fruit

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 235-242 ◽  
Author(s):  
A. H. McKay ◽  
H. Förster ◽  
J. E. Adaskaveg
Keyword(s):  
Management Practices ◽  
Citrus Fruit ◽  
The United States ◽  
Optimal Time ◽  
Inoculum Concentration ◽  
Time Of Application ◽  
Sour Rot ◽  
Green Mold ◽  
Highly Effective ◽  
Moderately Resistant

Few postharvest treatments are available for managing sour rot of citrus caused by Galactomyces citri-aurantii and they are generally not very effective. The demethylation-inhibiting (DMI) triazole fungicides propiconazole and cyproconazole were found to be highly effective and more efficacious than other DMIs evaluated, such as metconazole and tebuconazole, in reducing postharvest sour rot of citrus. Additional studies were conducted with propiconazole as a postharvest treatment because it has favorable toxicological characteristics for food crop registration in the United States and the registrant supports a worldwide registration. Regression and covariance analyses were performed to determine optimal time of application after inoculation and fungicide rate. In laboratory studies, decay incidence increased when propiconazole applications were delayed from 8 to 24 h (lemon) or 18 to 42 h (grapefruit) after inoculation. Effective rates of the fungicide were 64 to 512 μg/ml and were dependent on inoculum concentration of the sour rot pathogen and on the type of citrus fruit. Propiconazole was found to be compatible with sodium hypochlorite at 100 μg/ml and 1 to 3% sodium bicarbonate without loss of efficacy for decay control on lemon. The addition of hydrogen peroxide/peroxyacetic acid at 80 μg/ml slightly decreased the effectiveness of propiconazole. Heated (48°C) solutions of propiconazole did not significantly improve the efficacy compared with solutions at 22°C. In experimental packing-line studies, aqueous in-line drenches applied alone or followed by applications of the fungicide in storage or packing fruit coatings were highly effective, reducing sour rot to between 0 and 1.2% compared with 83.8% decay incidence in the control when treatments were made up to 16 h after inoculation. When the fungicide was applied in either fruit coating, decay was only reduced to 49.1 to 57.1% incidence. Tank mixtures of propiconazole with the citrus postharvest fungicides fludioxonil and azoxystrobin were highly effective in reducing green mold caused by isolates of Penicillium digitatum sensitive or moderately resistant to imazalil and sour rot. Propiconazole will be an important postharvest fungicide for managing sour rot of citrus and potentially can be integrated into current management practices to reduce postharvest crop losses caused by DMI-sensitive isolates of P. digitatum.

scholarly journals Establishment of Highly Efficient Agrobacterium Rhizogenes-mediated Transformation for Stevia Rebaudiana Bertoni Explants

2016 ◽  
Vol 58 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Żaneta Michalec-Warzecha ◽  
Laura Pistelli ◽  
Francesca D’Angiolillo ◽  
Marta Libik-Konieczny
Keyword(s):  
Agrobacterium Rhizogenes ◽  
Hairy Roots ◽  
Molecular Level ◽  
Stevia Rebaudiana ◽  
Culture Conditions ◽  
Light Conditions ◽  
Inoculum Concentration ◽  
Stevia Rebaudiana Bertoni ◽  
Pcr Method

Abstract Leaves and internodes from Stevia rebaudiana Bertoni plants growing in different conditions were used for transformation with two strains of Agrobacterium rhizogenes: ATCC 15384 and LBA 9402. Hairy roots formation was observed and the percentage of the transformed explants depended on the type of explant, time of inoculation and inoculum concentration. Inoculation of explants from ex vitro and in vitro plants with LBA 9402 strain led to higher efficiency of transformation than inoculation with ATCC 15384 strain. Growth rate of hairy roots in liquid culture was assessed under light and dark conditions. It was found that the growth of hairy roots decreased significantly under light conditions. Transformation of hairy roots growing in different culture conditions was confirmed at the molecular level using PCR method with primers constructed against rolB and rolC genes from A. rhizogenes.

scholarly journals Toward the Positional Cloning of qBlsr5a, a QTL Underlying Resistance to Bacterial Leaf Streak, Using Overlapping Sub-CSSLs in Rice

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e95751 ◽  
Author(s):  
Xiaofang Xie ◽  
Zhiwei Chen ◽  
Jinliang Cao ◽  
Huazhong Guan ◽  
Degong Lin ◽  
...  
Keyword(s):  
Positional Cloning ◽  
Bacterial Leaf Streak

scholarly journals Association Between Weather Variables, Airborne Inoculum Concentration, and Raspberry Fruit Rot Caused by Botrytis cinerea

2018 ◽  
Vol 108 (1) ◽  
pp. 70-82 ◽  
Author(s):  
Odile Carisse ◽  
Vanessa McNealis ◽  
Alissa Kriss
Keyword(s):  
Meteorological Data ◽  
Fruit Rot ◽  
Weather Variables ◽  
Storage Duration ◽  
Inoculum Concentration ◽  
Crop Losses ◽  
Airborne Inoculum ◽  
Average Relative Humidity ◽  
And Storage ◽  
Field Plots

Botrytis fruit rot (BFR), one of the most important diseases of raspberry (Rubus spp.), is controlled primarily with fungicides. Despite the use of fungicides, crop losses due to BFR are high in most years. The aim of this study was to investigate the association between airborne inoculum, weather variables, and BFR in order to improve the management of the disease as well as harvest and storage decisions. Crop losses, measured as the percentage of diseased berries during the harvest period, were monitored in unsprayed field plots at four sites in three successive years, together with meteorological data and the number of conidia in the air. Based on windowpane analysis, there was no evidence of correlation between crop losses and temperature, vapor pressure deficit, wind, solar radiation, or probability of infection. There were significant correlations between crop losses and airborne inoculum and between crop losses and humidity-related variables, and the best window length was identified as 7 days. Using 7-day average airborne inoculum concentration combined with 7-day average relative humidity for periods ending 6 to 8 days before bloom, it was possible to accurately predict crop losses (R2 of 0.86 to 0.89). These models could be used to assist with managing BFR, timing harvests, and optimizing storage duration in raspberry crops.

scholarly journals Efecto de la inoculación de Azospirillum spp. sobre el contenido nutrimental de moringa (Moringa oleifera Lam.)

2020 ◽  
Vol 38 (1) ◽  
pp. 29
Author(s):  
Mario Alejandro Hernández-Chontal ◽  
Dinora Vazquez-Luna ◽  
Ariadna Linares-Gabriel ◽  
Gloria Esperanza De Dios-León ◽  
Armando Guerrero-Peña ◽  
...  
Keyword(s):  
Crude Protein ◽  
Moringa Oleifera ◽  
Calcium Content ◽  
Dry Weight ◽  
The Other ◽  
Nutritional Content ◽  
Inoculum Concentration ◽  
Nutrient Contents ◽  
Animal Consumption ◽  
Moringa Oleifera Lam

Moringa is used for human and animal consumption due to its high content of proteins, vitamins and minerals. The present study analyzed and evaluated the effectiveness of Azospirillum spp. over the nutritional content of moringa (Moringa oleifera Lam.) under nursery conditions. The experimental design consisted of four treatments with six repetitions in complete blocks at random, which consisted of the inoculation at 0.5, 1 and 1.5 mL of suspension with 9.8 × 105 CFU mL-1 of Azospirillum spp. The study variables: biomass, protein, macro (P, K. Ca and Mg) and micronutriments (Na, Fe, Cu and Mn) in leaves and stems were determined 70 days after sowing. The analysis of variance showed signif icant statistical differences between treatments only for the variables: potassium content in leaves and calcium content, iron and sodium in stem. According to the comparison of means (P ≤ 0.05) the best treatments were those that received 0.5 and 1 mL of suspension. The inoculation of Azospirillum, failed to increase the dry weight and protein contents; however, the highest values (30.2% crude protein) were associated with its application. The absence of significant effects in the other variables evaluated is associated with inoculum concentration, however, higher values are shown in the nutrient contents in relation to results reported in other research.

scholarly journals Solid-state fermentation of paper sludge to obtain spores of the fungus Trichoderma asperellum

2019 ◽  
Vol 3 (2) ◽  
pp. 71-77
Author(s):  
Rosa Dorta-Vásquez ◽  
Oscar Valbuena ◽  
Domenico Pavone-Maniscalco
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Fermentation Process ◽  
Dry Mass ◽  
Paper Sludge ◽  
Ecological Risks ◽  
Trichoderma Asperellum ◽  
Optimal Conditions ◽  
Inoculum Concentration ◽  
Negative Environmental Impact

Abstract Paper production generates large quantities of a solid waste known as papermaking sludge (PS), which needs to be handled properly for final disposal. The high amount of this byproduct creates expensive economical costs and induces environmental and ecological risks. Therefore, it is necessary to search uses for PS, in order to reduce the negative environmental impact and to generate a more valuable byproduct. Due to the cellulolytic composition of PS, this work evaluated a solid state fermentation process using it as substrate to obtain spores of the fungus Trichoderma asperellum. Optimal conditions to obtain T. asperellum spores were: 60% water content, 3% (w/w) salts (Nutrisol P® and Nutrisol K®), inoculum concentration at 1x105 spores/g, and pasteurized or sterilized PS. Under these conditions it was possible to obtain 2.37x109 spores/g. T. asperellum spores applied directly to pepper (Capsicum anuum) seeds without PS increased significantly seedling dry mass in greenhouse assays. This work suggests an alternative, economic and abundant substrate for production of T. asperellum spores.

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