Optimization of zoospore production and inoculum concentration of Aphanomyces euteiches for resistance screening of pea and lentil

2019 ◽  
Vol 42 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Nimllash T. Sivachandra Kumar ◽  
Laura Cox ◽  
Cheryl Armstrong-Cho ◽  
Sabine Banniza
Keyword(s):  
Aphanomyces Euteiches ◽  
Resistance Screening ◽  
Inoculum Concentration ◽  
Zoospore Production

Mechanism for the Suppression of pea (Pisum sativum) Root Rot by Dinitroaniline Herbicides

Weed Science ◽  
1979 ◽  
Vol 27 (2) ◽  
pp. 195-201 ◽  
Author(s):  
J. R. Teasdale ◽  
R. G. Harvey ◽  
D. J. Hagedorn
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Solution Culture ◽  
Spore Production ◽  
Aphanomyces Euteiches ◽  
Sensitive Stage ◽  
Zoospore Production ◽  
Asexual Spore ◽  
Pea Roots ◽  
Dinitroaniline Herbicides

Pea (Pisum sativumL. ‘Elf’) root rot suppression by dinitroaniline herbicides could not be explained by a direct effect on the host. Pre-incubation of pea roots with 0.1 ppmw of oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) or trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) in solution culture did not alter their resistance to root rot. Furthermore, 0.1 ppmw of oryzalin or trifluralin did not alter the exudation of electrolytes or α-amino compounds from pea roots. Most of the dinitroaniline herbicides significantly inhibited mycelial radial growth of pathogen,Aphanomyces euteichesDrechs., at 1.0 ppmw and inhibited asexual spore production at 0.1 to 1.0 ppmw. Dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine), fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)aniline], and oryzalin inhibitedA. euteichesmycelial growth and asexual reproduction more effectively than the other dinitroaniline herbicides studied. The production of motile zoospores, the infecting propagule of the pathogen, was the most sensitive stage in the life cycle and was completely inhibited by 0.01 ppmw of all dinitroaniline herbicides tested. Since this concentration is below that estimated in the soil solution at registered rates of application, inhibition of motile zoospore production is sufficient to explain root rot suppression. Inhibition of pathogen motility resulted in a 2-week delay in the infection of pea roots. This delay allowed sufficient additional plant growth that the peas could better withstand the effects of subsequent disease development.

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 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.

Interactions between indigenous arbuscular mycorrhizal fungi and Aphanomyces euteiches in field-grown pea

Mycorrhiza ◽  
2002 ◽  
Vol 12 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Lars Bødker ◽  
Rasmus Kjøller ◽  
Kristian Kristensen ◽  
Søren Rosendahl
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Aphanomyces Euteiches

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.

Zoospore Production Biology of Pythiaceous Plant Pathogens

2013 ◽  
Vol 162 (2) ◽  
pp. 69-80 ◽  
Author(s):  
Michael Pistininzi ◽  
Edward Weiss ◽  
Lauren Achtemeier ◽  
Chuanxue Hong
Keyword(s):  
Plant Pathogens ◽  
Zoospore Production ◽  
Production Biology

Zoospore production in Pythium spinosum

1993 ◽  
Vol 97 (12) ◽  
pp. 1495-1498 ◽  
Author(s):  
W.J. Botha
Keyword(s):  
Zoospore Production

scholarly journals Selection of Biocontrol Agents of Pink Rot Based on Efficacy and Growth Kinetics Index Rankings

Plant Disease ◽  
2011 ◽  
Vol 95 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Tugba Adiyaman ◽  
David A. Schisler ◽  
Patricia J. Slininger ◽  
Jennifer M. Sloan ◽  
Mark A. Jackson ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Oxygen Depletion ◽  
Bacterial Strains ◽  
Γ Irradiation ◽  
Commercial Development ◽  
Biocontrol Efficacy ◽  
Pink Rot ◽  
Production Values ◽  
Zoospore Production ◽  
Significant Difference

The microbiota of 84 different agricultural soils were transferred to separate samples of a γ irradiation-sterilized field soil enriched with potato periderm, and the resulting soils were assayed for biological suppressiveness to Phytophthora erythroseptica and their effect on zoospore production. The 13 most suppressive soil samples, which reduced zoospore production by 14 to 93% and disease severity on tubers by 6 to 21%, were used to isolate 279 organisms. Fourteen strains that reduce pink rot infections in preliminary tests were selected for further study. Six bacterial strains that reduced the severity of disease (P ≤ 0.05, Fischer's protected least significant difference) in subsequent tests were identified as Bacillus simplex (three strains), Pantoea agglomerans, Pseudomonas koreensis, and P. lini. Relative performance indices (RPIs) for biocontrol efficacy and for each of four kinetic parameters, including total colony-forming units (CFUmax), biomass production values (DWmax), cell production after 8 h (OD8), and time of recovery from oxygen depletion (DT) were calculated for each strain. Overall RPIEff,Kin values for each strain then were calculated using strain RPI values for both efficacy (RPIEff) and kinetics (RPIKin). Strains with the highest RPIEff,Kin possess the best biocontrol efficacy of the strains tested and liquid culture growth characteristics that suggest commercial development potential.

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