170770-CR351.pdf
Screening for efficient biocontrol microorganisms to
manage fusarium wilt of cyclamen
Lecomte C.1,2, Bouksil H.2, Edel-Hermann V.2, Langlois A.1, Robert F.1, Steinberg C.2, Alabouvette C.3
E-mail : charline.lecomte@astredhor.fr

Introduction

Fusarium wilt of cyclamen
0 Fusarium oxysporum f. sp. cyclaminis
(Focy)-Tracheomycosis
0 The most destructive disease on cyclamen
0 Up to more than 50 % losses

No efficient and
eco-friendly
solution
Prophylactic measures
Highly recommended

Varietal breeding
Nonexistant

Chemical
No curative control

Biocontrol

Promising results

objectives
0 Design of a specific molecular marker for early detection of the pathogen
0 Selection of one or several efficient BioControl Agents (BCA)
Methods

BCA tested
0 Marketed products but without
allegation to control Focy
0 7 products
0 Tested alone or in combination
0 Mode of action evaluated in vitro

Product number
1
2
3
4
5
6
7

3-4 leaves seedlings transplanting

Cyclamen sowing

12 weeks

106 cfu*
of product/L substrate

Type of microorganisms
Fungus
Bacteria
Mycorhizal fungus
Fungus and bacteria
Fungus
Fungus
Fungus

1st Focy inoculation

0 A strain (MIAE01507) isolated
from a cyclamen seedling in
2009 and known as highly
aggressive
0 15 inoculated plants/treatment
2nd Focy inoculation

Disease incidence assessment

11 weeks

1 week

106 cfu
of product/L substrate

The Focy strain

106 , 105, and 104 cfu
of pathogen/L substrate

106 , 105, and 104 cfu
of pathogen/L substrate

Number
of dead plants/treatment
*cfu: colony forming unit

REsults

Biocontrol test

0 Efficient products?
A Only tendances
A Phytotoxicity or slow down emergence effect: 3, 6
A Inefficient products: 4, 5, all combinations
A Selected for further tests: 1, 2, 7

BCA’s modes of action

3 Focy/BCA ratios tested: 1/1, 1/10, 1/100
80%

Percentage of dead plants

0 Post sowing problems
A Seedling emergence, phytotoxicity, Botrytis development
A Not enough plants available: ratio 1/1 not tested*

Concentration
of Focy (cfu/L
of substrate

70%
60%
50%

0

40%

10 4

30%

10 5

20%

10 6

10%

0 Several modes of action highlighted:
A Antibiosis: 2
A Mycoparasitism: 4, 5, 7

0%

*

*

*

*

*

CONCLUSION

Acknowledgements

0 Some products showed a phytotoxic effect on cyclamen
0 Three promising products identified and selected for further tests
0 Microorganisms showed various modes of action against Focy

Nadine Gautheron • Marc-Antoine Cannesan • Yohann Daguerre •
Sébastien Terrat
Mars 2015 • Crédits photos : Astredhor

Astredhor, 44, rue d’Alésia, 75682 Paris, France; 2 INRA Dijon, UMR 1347
Agroécologie, 17 rue Sully, 21065 Dijon, France; 3 Agrene, 47 rue C. Pierrot, 21000
Dijon, France

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