Biocontrol And P. Infestans Diversity . - Aarhus Universitet
Federal Department of Economic Affairs,Education and Research EAERAgroscopeBiocontrol and P. infestans diversity:the potential of antagonistic bacteriaMout De VriezeAgroscope, Institute for Plant Production Sciences, Wädenswil & Nyon16.05.201722.01.2015www.agroscope.ch I good food, healthy environment
Why bacteria and where to find them? the plant microbiomeDiversity of microorganisms selected by the plant potentially modified upon infection with apathogen potentially beneficial and/or protectiveEuroblight Workshop, Aarhus May 2017Mout De Vrieze2
Isolation of microbiome inhabitants Overall most active strains belong to thegenera Pseudomonas, (also Bacillus,ControlArthrobacter and Microbacterium) Selected 9 Pseudomonas strains withPhyllosphere strains varying anti-Phytophthora activityRhizosphere strainsLukasHunzikerDeniseBönisch3Euroblight Workshop, Aarhus May 2017Mout De VriezeHunziker et al., 2015Guyer et al., 2015
Mode of action What stage of the Phytophthora lifecycle dothe bacteria affect?Colonisation abilityExploring the bacteria’s potential Is the anti-Phytophthora activity maintainedon leaf tissue? How are these life stages affected? In vitro assays Are the strains capable of establishingthemselves on potato plants? In planta assaysLab strain Rec01 (Zürich, 2001) but are these effects maintained when using a different P. infestans strain?Euroblight Workshop, Aarhus May 2017Mout De Vrieze4
Collection of P. infestans 2015 In 2015 :- 60 infestations reported- 27 samples (infected leaves) collected from 19 fields- 22 isolates were successfully retrievedRamona GloorCharacterization of : Mating type Morphology Pathogenecity Virulence SSR Fungicide resistanceEuroblight Workshop, Aarhus May 2017Mout De Vrieze5
How aggressive are the isolates?Black’s differential set 11 R-genes : R1 – R11 R0 & Bintje Susceptible cultivars (no R-genes) Gasore & Sarpo Mira Resistant cultivars Pathogenecity testLeaf disc assay-Infection/noinfection15 discs perlineage andisolateEuroblight Workshop, Aarhus May 2017Mout De Vrieze7 days6
How aggressive are the isolates? The most aggressive isolates are among the Blue 13 MLGEuroblight Workshop, Aarhus May 2017Mout De Vrieze7
How aggressive are the isolates? Resistance to MefenoxamPresence of A1 and A2Euroblight Workshop, Aarhus May 2017Mout De Vrieze8
Is pathogenicity correlated to virulence?What about virulence?Leaf discassay49.4 %7 days2.8 % The most virulent isolates are not necessarily the most aggressiveEuroblight Workshop, Aarhus May 2017Mout De Vrieze9
Is virulence correlated to morphological traits? Correlation with morphological traits? Fast growing strains produce less sporangiaHigher sporangia production results in smaller sporangiaSmaller sporangia appear to be more virulentIsolates producing many small sporangia are more virulent Correlation with mating type? A1 isolates are more virulent Correlation with origin?VirulenceEuroblight Workshop, Aarhus May 2017Mout De Vrieze10
Back to the bacteria MyceliumSporangiaProtection on plant Survival on plantMycelial MycelialSporangia Sporangia germinationCoSprayinggrowth on growth onproductioninoculationRARA %Germ tubeR32R47R76R84S04S19S34S35S49P. vranovensisP. chlororaphisP. fluorescensP. marginalisP. frederikbergensisP. frederikbergensisP. jesseniiP. marginalisP. 222222112222222123133222Stems121211111 Scoring according to performance Selected 3 bacteria based on varying effects on mycelial growth and sporangiagerminationEuroblight Workshop, Aarhus May 2017Mout De Vrieze11
Inhibiton of mycelial growth by the bacteriaControl Dual assayEuroblight Workshop, Aarhus May 2017Mout De Vrieze12
Zooming in on sporangia germination Both sporangia germination and sporangia length are affected by thebacteriaEuroblight Workshop, Aarhus May 2017Mout De Vrieze13
Is the antagonistic effect maintained on planttissue? The bacteria successfully reduce symptom developmentSG-9475-An, mating type A1 is less susceptibleEuroblight Workshop, Aarhus May 2017Mout De Vrieze14
OutlookAdithiAurélienRavikumarBailly CLSA and GC-MS to identify volatileorganic compounds (VOCs) Diffusible compoundsHCNR47 TLC Genome mining (9 strains) Looking for genes1-undecenePhenazines Comparative genomics comparison of genomes of strainsshowing varying activityMMTSHPR Field trial : foliar treatmentsusing bacterial strains- Effect of combinations ofstrains- Survival of strains under fieldconditionsEuroblight Workshop, Aarhus May 2017Mout De VriezeDMDSPyrrolnitrinDMTS15
AcknowledgementsInstitute for Plant ProductionSciences, Nyon & WädenswilUniversity of FribourgDr. Katia Gindro and Mycology GroupNicolas VuilleRamona GloorJosep Massana CodinaDr. Jürg FreyAdithi Ravikumar VaradarajanDr. Christian AhrensProf. Laure WeisskopfUniversity of ZürichDr. Aurélien BaillyInstitute for Sustainibility Sciences,ReckenholzAnouk GuyerAlessia GandolfiEuroblight Workshop, Aarhus May 2017Mout De Vrieze16
Thank you for yourattentionEuroblight Workshop, Aarhus May 2017Mout De Vrieze17
Euroblight Workshop, Aarhus May 2017Mout De Vrieze18
Mode of action?Dual cultures in Petri dishes 9 Pseudomonas strains Different P.infestans strainsControl :Euroblight Workshop, Aarhus May 2017Mout De VriezeRed : the pathogen is strongly inhibitedGreen : the pathogen is growing well19
Euroblight Workshop, Aarhus May 2017Mout De Vrieze20
Mode of action?% germinatedsporangia Sporangia germination Sporangia viability60 Propidium iodide stainingAlive4020R470Length of germtube(µm)300Dead52 %48 %98 %2%8%92 %S49200S041000 Zoospore motility and chemotaxisAsparticacidControlEuroblight Workshop, Aarhus May 2017Mout De VriezeR47 supernatant21
Is the anti-Phytophthora activity maintained on leaftissue? In vivo test on leaf discs : coinoculation on leaf tissue3,0Surface convered with mycelium (%)VictoriaBintjeLady Claire4,02,01,00,025Pinf S34 R02 S35 R74 R76 R84 S50 S04 S49 R32 R01 S19 R95 S22 R47 neg201510505,0Pinf S34 R02 S35 R74 R76 R84 S50 S04 S49 R32 R01 S19 R95 S22 R47 neg4,03,02,01,00,0Pinf S34 R02 S35 R74 R76 R84 S50 S04 S49 R32 R01 S19 R95 S22 R47 negEuroblight Workshop, Aarhus May 2017Mout De Vrieze22
Can the bacteria colonise potato plants? Tuber inoculationJosep MasanaCodina Leaf application Bacterial suspensions(OD 1) Bacterial suspensions(OD 1) Stem cuts Leaf discsR32R47R76R84S04S19S34S35S49 CFU countSurface sterilised retrieved after 3 weeks retrieved after 4 weeks retrieved after 5 weeksEuroblight Workshop, Aarhus May 2017Mout De Vrieze 1,0E 08CFU/cm2 of leaf surfaceNot sterilised1,0E 071,0E 061,0E 051,0E 041,0E 031,0E 021,0E 011,0E 00Day 0R32R47Day 1R76Day 4S3523
Workshop, Aarhus May 2017 15Euroblight Mout De Vrieze Outlook CLSA and GC-MS to identify volatile organic compounds (VOCs) Diffusible compounds TLC Genome mining (9 strains) Looking for genes Comparative genomics comparison of genomes of strains showing varying activity HCN 1-undecene
tion diversity. Alpha diversity Dα measures the average per-particle diversity in the population, beta diversity Dβ mea-sures the inter-particle diversity, and gamma diversity Dγ measures the bulk population diversity. The bulk population diversity (Dγ) is the product of diversity on the per-particle
AFMC Diversity, Equity, Inclusion and Accessibility (DEIA) Training 2 2 Diversity in BusinessDiversity in Business 3 Minutes 3 The Importance of Diversity The Importance of Diversity3 Minutes 4 The Power of Diversity 4 Minutes The Power of Diversity 5 The Threat of Diversity 2 Minutes The Threat of Diversity 6 Diverse Teams Deliver Results 1 Minute Diverse Teams Deliver Results
diversity of the other strata. Beta (β) Diversity: β diversity is the inter community diversity expressing the rate of species turnover per unit change in habitat. Gamma (γ) Diversity : Gamma diversity is the overall diversity at landscape level includes both α and β diversities. The relationship is as follows: γ
pasture productivity by competing with desirable forage plants. An added problem is the loss of the pasture legumes if phenoxy herbicides are used to control this weed. The Scotch thistle gall fly (Urophora stylata) is native to Europe and is a classical biocontrol agent for Scotch thistle that was released in New Zealand in 1998.
local diversity (alpha diversity) and the complement of species composition among sites within the region (beta diversity), and how these diversities contribute to regional diversity (gamma diversity) [35, 37]. The influence of alpha and beta diversities on gamma diversity is an essential aspect of local and landscape level conservation plans [38].
Biology of Fungi Lecture 2: Diversity of Fungi Page 6 of 16 Q Phylum Oomycota l Economically important fungus-like organisms that have extremely significant environmental roles in agriculture l Causes of the following plant/fish diseases: F Potato blight (Phytophthora infestans) F Sudden oak death (Phytophthora ramorum) F “Decline” diseases (Pythium spp.)
alpha, beta, and gamma diversity. Alpha (α) diversity is local diversity, the diversity of a forest stand, a grassland, or a stream. At the other extreme is gamma (γ) diversity, the total regional diversity of a large area that contains several communities, such as the eastern deciduous forests
Albert Woodfox a, quant à lui, vu sa condamnation annulée trois fois : en 1992, 2008, et . février 2013. Pourtant, il reste maintenu en prison, à l’isolement. En 1992 et 2013, la décision était motivée par la discrimination dans la sélection des membres du jury. En 2008, la Cour concluait qu’il avait été privé de son droit de bénéficier de l’assistance adéquate d’un .
