CIRAD – IRD - CEMAGREF

PRAM

R

M

CIRAD – IRD - CEMAGREF

Cuba

Sto Domingo Puerto Rico

Martinica

Different labs, Culture chambers

& experimental fields

Venezuela

& experimental fields

Nematology

(P.Quénéhervé – IRD)

Agro-physiology

(A.Soler – CIRAD)

(P.Marie-Alphonsine – CIRAD)

Martinica (FWI)

MD-2 Pineapple

C AN SYSTEMIC RESISTANCES CONTRIBUTE TO ECOLOGICALLY BASED IPM CONTROL OF NEMATODES IN PINEAPPLE ( ^{AND BANANA} )?

Rotylenchulus reniformis

Soler A. (alain.soler@cirad.fr) and Marie-Alphonsine P.A., CIRAD Martinique, Quénéhervé P., IRD Martinique, PRAM. Tel (596) 596 42 30 92 Martinique

Hanseniella spp

C l a s s i c a l P i n e a p p l e a n d B a n a n a c r o p p i n g s ys t e m s n e e d h i g h l e ve l o f p e s t i c i d e s i n p u t ( f u n g i c i d e , n e m a t i c i d e a n d

i n s e c t i c i d e )

The

The reduction reduction of pesticides in of pesticides in cropping cropping systems

systems : a : a grow ing grow ing concern concern for for agronomic agronomic research

research during during the last 15 the last 15 years years

i n s e c t i c i d e )

i n B a n a n a : p e s t i c i d e a m o u n t s d i vi d e d b y 1 0 i n t h e l a s t d e c a d e ( u s e o f t i s s u e c u l t u r e p l a n t a n d i m p r o ve d d e s t r u c t i o n o f p l a n t s b e f o r e f a l l ow )

i n P i n e a p p l e : p r o p h yl a c t i c m e a s u r e s a n d

m o s t p e s t i c i d e s n o t a l l ow e d a n ym o r e

The

The reduction reduction of pesticides in of pesticides in cropping cropping systems

systems : a : a grow ing grow ing concern concern for for agronomic agronomic research

research during during the last 15 the last 15 years years

Example for pesticides application schedule

Objective Objective

Pineapple and Banana cropping systems with reduced use of pesticides to control soil borne parasites

Can systemic resistances contribute to ecologically based IPM control of nematodes in pineapple (and banana)?

of nematodes in pineapple (and banana)?

To induce plant natural defenses against nematodes by different elicitors in pineapple and bananas.

To characterize physiologically the induced systemic resistance.

To induce ISR effective against nematodes with local

micro-organisms (diazotrophic bacteria and mycorhizia).

To integrate ISR in ecologically based IPM for pineapple .

I n i t i a l p h y s i o l o gi c al p r o c e s s e s i n S y s t e m i c R e s i s t a n c e s

.

( r e c o g n i z i n g , e a r l y r e s p o n s e , d e f e n s e r e a c t i o n s )

Oxydative Burst Cell membrane

permeability Pathogens or

Elicitors Extra cellular medium

Cell Wall

Cell membran

Cytoplasm

PR Proteins as Chitinases β1,3 Glucanase

Acidification

Cell wall reinforcement Toxic compounds

Cytoplasm Methyl-

jasmonate

Salicylic acid

Experimental design

Elicitor treatments:

1) Elicitor then

2) Inoculation Individual pots – greenhouse

Elicitor treatments:

-Methyl jasmonate (10^-4M), Salicylic ac (10^-3M), β 1,3 Glucans (Laminarin 20g/L) -Solutions : 20 or 50 mL directly on the soil.

Timing:

Main Observations:

- Nematodes counting

- Characterizing physiological changes with few enzymatic activities Oxidatives enzymes : CAT, SOD, APX, PPO, POD

2 Key enzymes for signaling molecules pathways : LOX, PAL

T0 Week1 Week2 Week4 Week10

3 Elicitor Nematodes Nematodes

applications inoculation counting

+ Root extracts

on non inoculated plants

2 Pineapple varieties

Smooth cayenne,

nematodes sensitive

MD-2,

more tolerant

R ^ESULTS

R ^ESULTS

Effect of NDS on the development of Rotylenchulus reniformis on MD-2

(Tolerant variety)

Box plots for data on the total* nematode population after elicitor applications on the root system of MD-2.

*(Total stands for “adults + pre adults + eggs”.) - 7 replicates.

Most of the decreases ranged 30 to 70%.

Fecondity was particularly affected with reduced egg numbers.

Effect of NDS on the development of

Rotylenchulus reniformis on Smooth cayenne

(Sensitive variety)

Box plots for data on the total* nematode population after elicitor applications on the root system of Smooth Cayenne. *(Total stands for “adults + pre adults + eggs”.) - 7 replicates.

No decrease of populations.

Fecondity was not affected with reduced egg numbers.

Effect of NDS on the development of Rotylenchulus reniformis on pineapple

Oxidative enzymes controlling toxic reactive oxigen species

- CAT decrease = more H₂O₂ involved in plant defense.

(direct toxicity or signaling molecule) -SOD = firstline of defense against ROS toxicity

Smooth Cayenne

MD-2

Effect of NDS on the development of Rotylenchulus reniformis on pineapple

Enzymes controlling the signaling molecules pathways

- LOX increase = enhanced biosynthesis Methyl-jasmonate, (Induced Systemic Resistance?).

- PAL decrease not clear = less phenylpropanoids involved in plant defense.

=> Balance between SA and Met-jasm pathways

Smooth Cayenne

MD-2

C ^ONCLUSION / P ERSPECTIVES

-

S i n g l e p o t – C o m p a r i s o n b e t w e e n a t o l e ra n t v a r i e t y ( M D - 2 ) a n d a s e n s i t i v e v a r i e t y ( S C )

- Although similar physiological changes after elicitor treatment are observed on both varieties, efficient plant natural defenses against nematodes were set up only on the tolerant variety.

- Meaning of enzymatic changes ? (Part of the early response)

- Plant defenses linked to ‘genetic’ tolerance ?

- Demonstration of Induced Systemic Resistance set up : Use of split root system (in progress)

- Use of local micro-organisms for Induced Systemic Resistances (ISR) ? (Diazotrophic bacteria and mycorhizia)

- Which cultural practices in new cropping systems can enhanced ISR through micro-organisms?

Single pot

Split-root

(Signaling Molecules) Methyl jasmonate Salicylic acid

β-1,3-glucans

Different Plant Natural Defense

Stimulators tested on pineapple and banana

Many compounds and organisms may induce

(Plant growth stimulator) Fenugrec seed extract

Stifénia    

(non pathogenic Fungus) Trichoderma harzianum Ponthoscolex corethrurus (Earthworms)

organisms may induce plant natural defenses.

- often efficient against pathogenic fungi

- very few tested

against nematodes.

Effect of NDS on the development of Rotylenchulus reniformis on MD-2

(Tolerant variety)

d e n s it y )

Global results

Evolution of Rotylenchulus reniformis populations

(% o f c o n tr o l - d e n s it y

Effect of NDS on the development of Pratylenchus coffeae on Cavendish

( s e m i S e n s i t i v e v a r i e t y )

d e n s it y )

Global results

Evolution of Pratylenchus coffeae populations

(% o f c o n tr o ls - d e n s it y

Induced

Induced Systemic Systemic Resistance ? Resistance ?

Pathogenic fungi

Split-root system

Signaling molecules

(Met Jasm. Ethylène…)

Split-root

Elicitor treatment

- Chemical compounds - Micro-organisms

Nematodes

Effect of NDS on the development of Pratylenchus coffeae on Cavendish

( s e m i S e n s it ive v a r i e ty )

Preliminary results 5 replicates

Slight decrease of Pratylenchus coffeae (p=0.623) by induced systemic resistance on the sensitive variety Cavendish

Pratylenchus coffeae and banana varieties with different

sensitivity o the nematode

Different banana hybrids from CIRAD, resistant to Different banana hybrids from CIRAD, resistant to Black Sigatoka, showed also some tolerance to nematodes.

Their capability to set up Induced Systemic

Resistances is under evaluation using the same

split root system used for Pineapple.

Banana varieties with different sensitivity o the nematode

(P.Quénéhervé – IRD / PRAM)

T HANK YOU FOR YOUR ATTENTION

T HANK YOU FOR YOUR ATTENTION