duperie olfactive et pollinisation chez le palmier à huile palmier 2012... · duperie olfactive et...
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Duperie olfactive et pollinisation chez le palmier à huile
Laurence BEAUDOIN‐OLLIVIER
Brigitte FREROT
Alassane COFFI, Albert FLORI
Journée Filière Palmier à Huile – juillet 2012
A strategic crop for South Countries
Monocotyledone Arecaceae (Palmacae)
Oil demand : +3% per year since 30 years
11 kg / m / year in 197520,5 kg in 200525 kg in 2020
For 9,2 milliards of people in 2050 : 230 millions tonnes
Pollination is important for fruit set and production
• Female flower : bunch 3 to 50 kg (300 to 3 000 fruits)• 27 months between flower sex differentiation and bunch harvest.• 6 months between flowering and harvest
Reproduction : OP is monoecious and allogamous, cross fertilization
Elaeidobius spp. interactions with oil palm flowerspollination
Mutualism
♀ flower mimics ♂ flower odor(s)Deception but pollination
Elaeis oleifera Elaeis guineensis© T. D
urand‐Gasselin
© T. D
urand‐Gasselin
© T. D
urand‐Gasselin
InterspecificHybrid
Objectives
• Get knowledges on interactions between E. oleifera and E. guineensis and Elaeidobius spp.
• Optimizing pollination in South East Asia
• Evaluating the selected varietes
• Optimizing pollination of the interspecific hybrid
Study on the relation between flower
in anthesis and insect attraction
Chemical and behavioral approaches
Comparative study of Elaeidobius attraction by
male and female flowers for both
E. oleifera and E. guineensis
Elaeidobius attracted to male and femaleflower in anthesis using glu traps
Anova : No difference between FMA & FFA E. guineensis for all the Elaeidobiusspecies.
All Elaeidobius sp are collected aroundE. guineensis flowers (♂ and ♀).
0
10
20
30
40
50
60
Average
of insects trap
ped (n=2)
Espèces
MFA guineensis
FFA guineensis
0
10
20
30
40
50
60
Average
of insects trap
ped
per flower (n
=2)
Espèces
MFA oleifera
FFA oleifera
Insects trapped during COV collection (male flower in anthesis)
0
50
100
150
200
250
Oleifera Guineensis
E kamerunicus
E plagiatus
E subvittatus
0
50
100
150
200
250
EK ♂ EK♀ Ep♂♀ ES ♂♀
Oleifera 1/2
Oleifera 2/2
Guineensis
E. oleifera attracts mainlyE. plagiatus and then subvitatus
E. guineensis attracts several Elaeidobius species whereas E. oleifera does not attract E. kamerunicus
There are differences of attractivity depending of Elaeis species
CONCLUSION
Behavior tests
Nb of insectsn =11
MFA FFA No choice
Initial choice 4 5 2
Final choice 7 2 2
FFA Eg MFA Eg
For initial choice, 50:50When initial choice is MFA = definitive choiceWhen initial choice is FFA then definitive choice is MFA
0
1
2
3
4
5
6
7
8
MFA FFA No choicenb
of insects te
sted
insect choice
Initial
Final
MFA Eo MFA Eg MFA Eg MFA Eo
N=50 MFA Eg MFA Eo no choiceE. kamerunicus 9 0 5E. plagiatus 6 1 5E.subvitattus 13 4 7total 28 5 17
N= 34 MFA Eg MFA Eo no choiceE. kamerunicus 6 0 3E. plagiatus 6 2 0E.subvitattus 7 3 7total 19 5 10
Choice between male flower E. guineensis and E. oleifera
No significative difference between left or right sides
MFA Eg significantly more attractive than
MFA Eo
0
2
4
6
8
10
12
14
MFA Eg MFA Eo No choice
nb of insect tested
insect choice
Ek
EP
ES
0
2
4
6
8
10
12
14
MFA Eg MFA Eo No choice
nb of insect tested
insect choice
Ek
EP
ES
Choice between male flower for E. guineensis and E. oleifera forE. subviattus depending of flower status
MFA Eo MFA Eg
N=30 MFA Eg MFA Eo no choice
E.subvitattus 6 7 17
MFA Eo MFA Eg
N=19 MFA Eg MFA Eo no choice
E.Subvitattus 12 7 0
MFA J0 of collection MFA J+1 after collection
No difference between fresh and older flowersFor insects making a choice (n=32), no significant difference between Es for Eg (56%) and Es for Eo (50%). But only 32 insects ….
0
2
4
6
8
10
12
14
16
18
MFA Eg MFA Eo No choice
nb of insect tested
E. subvittatus choice
0
2
4
6
8
10
12
14
16
18
MFA Eg MFA Eo No choice
nb of insect tested
E. subvittatus choice
Elaeidobius is able to discrimate sex of the flower : MFA is more attractive to the insect.
MFA E. guineensis are more attractive than MFA E. oleifera for ALL Elaeidobius species together and there is no difference depending of sides.
For E. subvitatus, the difference of attraction between both palms may be less strong and there is no differenceof attraction between fresh and older flowers
CONCLUSION
COV collection
GC‐MS analysis
• VARIAN 3400 and VARIAN ion Trap
• GC– Rxi‐5ms. 30 m, 0.32 id.
– 50°C to 300°C at 8°C /min.
• MS– 70eV,40 to 350 AMU.
1
3
2
2
2
4
3
N°1 missing
N°4 missing
Elaeis oleifera
Elaeis guineensis
Results :
Differences in the compositions of the odors released by the two species
Quantities are lower in E. oleifera than in E. guineensis
Comparison of odors released by male flowers in anthesis of Elaeis oleifera (red) and Elaeis guineensis(green)
2
2
3
4
3 trace
N°4 missing
N°1 missing
N°1 missing
Elaeis oleifera
Elaeis guineensis
Comparison of odors released by female flowers in anthesis of Elaeis oleifera (red) and Elaeis guineensis (green) (Bénin)
Results : Differences in the compositions of the odors released by the two speciesQuantities are lower in E. oleifera than in E. guineensis
MAJOR RESULTS
• In both EG et EO, we found differences between male and female flower odors.
‐ The female flowers did not mimic completely the odor of male flowers
• There are differences between composition of E. oleifera and E. guineensis
‐ E. oleifera produced a lower quantity of global volatile compounds than E guineensis
‐ Some compounds are only produced by E. oleifera (1, 4)‐ The differences in odors is correlated with differences in the insect behavior
Conclusions (1)
Elaedobius spp. are attracted by both oil palm species but are able to distinguish them
Main compounds are different depending of the oil palm species.
Conclusion (2)
• Pollination parameters have to be taken into account by the breeders to maintain an effective system
• Odors might be a pollination quality marker
Expected results 1/2Short terms :
– Identification of chemical cues that indicate the necessity or not for hand pollination in:
• existing hybrids• future hybrids
– knowledge on variability in odour production should help to understand variability in pollination quality
Long terms: – Identification of chemical cues that act on insect pollination behavior to develop:
• Pollination spot: insects are attracted by artificial odors in a spot with pollen
– Create palm tree hybrids compatible with what pollinator insects request for visiting flowers
Expected results 2/2
Population dynamicInsect activity period (daytime, night….)Flight activity depending of planting materialFlight ability and distance (flight mill experiment)
Short term
Understanding mechanisms of flowerpollination (olfactometer tests and field tests)‐ Recognition of the sex, the stage, the planting material by the insect‐ Evaluation of identified compounds on insect behavior to develop a synthetic attractant
Long term