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Rouseff, R., Onagbola, E., Smoot, J. and Stelinski, L. Rouseff, R., Onagbola, E., Smoot, J. and Stelinski, L. CITRUS Research & Education Center
Rouseff, R., Onagbola, E., Smoot, J. and Stelinski, L.Rouseff, R., Onagbola, E., Smoot, J. and Stelinski, L.
CITRUS Research & Education CenterCITRUS Research & Education Center
HLB/GreeningHLB/GreeningHuanglongbing = yellow shootHuanglongbing = yellow shootOriginated in SE Asia/India/Africainfected trees produce small, misshapened fruituinfection spread by Asian Citrus Psyllid
d li d di i ftrees decline and die in a few yearsthere is currently no curey
photo: Jamie Yates
photo: Jamie Yates
photo : Michael Rogers
Citrus Industry, February 2007
ObjectivesObjectivesIdentify the active components (volatiles) in guava leaves that repel or reduce psyllid populations and avoid the negative aspects of guava trees/fruit.Develop controlled release device for pdelivery of repellent chemicals in the fieldPractical application of this research:Develop effective repellent to protect citrus from psyllidDevelop effective repellent to protect citrus from psyllid infestation
Human Aroma AssessorsHuman Aroma AssessorsData System
Sample
Injector
OvenDetector
Gas
Aroma active compounds in Orange Juicepo
nse
FID
Resp
nse
Fry
Res
po
0 255 10 15 20Olfa
ctor
0 255 10 15 20
Time (min)
Norisoprenoids in Orange JuiceNorisoprenoids in Orange Juice
al e el
pons
e
Dec
ana
L-c
arvo
ne
Vale
ncen
e
neceno
ne
onecyclo
citra
FID
Resp L V
β-io
non
β-da
mas
α-io
n oβ-
nse
Fry
Res
po
1 613 1415
20 22
Olfa
ctor
423
65
79
10
11128
16 1719 21 23 24
18
Time (min)12 14 16 18 20
Initial ReasoningActive guava volatile non obviousMust be from leaf not fruitMust be found in guava not citrusMust be found in guava not citrusSulfur volatiles biologically active g y
Biologically Active Sulfur CompoundsBiologically Active Sulfur CompoundsBalandrin, M. F.; Lee, S. M.;
Klocke, J. A., Biologically active volatile organosulfur compounds from seeds of the neem tree J. Agric. Food Chem. 1988, 36, (5), 1048-54.
di l di lfid hi h
neem seeds (Azadirachta indica)
di-n-propyl disulfide, which is larvicidal to Aedes aegypti(L.) (Diptera: Culicidae) neem seeds (Azadirachta indica). ( ) ( p )(yellow fever mosquit0
Plants Produce Defensive VolatilesDugravot, S.; Mondy,
Plants Produce Defensive Volatiles
N.; Mandon, N.; Thibout, E., Increased sulfur precursors and volatiles pproduction by the leek Allium porrum in response to specialist insect attackto specialist insect attack. J. Chem. Ecol. 2005, 31, (6), 1299-1314.
dipropyl disulfidepropyl propenyl
di lfiddisulfide
Pulsed Flame Photometric Detection
1 2ignition
3propagation
4combustion
5extinction
1 2ignition
3propagation
4combustion
5extinction
1 2ignition
3propagation
4combustion
5extinction
Sulfur detection time windowSulfur detection time window
SolidPhaseMicroMicroExtraction
Coated Silica FiberExtraction
Headspace
Coated Silica Fiber
Headspace
LeavesLeaves
SamplesSamplesLeaf flushes from:Leaf flushes from:
‘white guava’ (P. guajava L.;Myrtaceae)Valencia and Hamlin sweet orange (Citrus
sinensis L. Rutaceae),Ray Ruby grapefruit (C. paradisi Macf.)rough lemon (Citrus limon Burm.)
Sample size approx. 3.5g
Volatile CollectionVolatile Collection
SPME H d T h iSPME Headspace TechniqueSample equlibrated at roomSample equlibrated at room temperature for 30 min.Fiber exposed for 1 or 15 min.
t t d d i t d i t GCretracted and inserted into GC injectorj
Guava Leaf Sulfur Volatiles
DM
S
pons
e
ol
SO2
DS
D R
esp
than
ethi
DM
D
PFPD
H2S
Met
Crushed Leaves
2.0 3.0 4.0 5.0 6.0
Time (min- wax)
Guava vs CitrusGuava vs Citrus
B th P d i il h dBoth Produce similar uncrushed sulfur chromatogramsg
Only Guava produces DMDS
Restek Stabilwax column 40-240@7°, 15-May-2008 + 15:35:49SPME 2ph 1cm RT 30 min equil 1min exp
100
DB Wax SPME_Guava-Crush_01_051509 Scan EI+ TIC
9.63e914.38
10 18
10.09
/ 79
TIC1.02e9
10.18m/z = 79
%
10.18
TIC
25.6226.81
10.80
TIC 22.80
16.03
23.40
13.3811.57
10.18 12.9512.54
13.45
14.14
16.32
17.38
16.59
22.50
19.8420.93 21.93
24.25
23.88
25.94
26.13 29.01
9.00 11.00 13.00 15.00 17.00 19.00 21.00 23.00 25.00 27.00 29.00Time3
Time (min- wax)
100
79 94 Sample
5045
Sample
ty
47 6164
96
Inte
nsit
0
49
4964
aliz
ed I
50 47
496164
Nor
m
SS
79Standard
40 60 80 100 120100 45 94
m/z
www.ars-fla.com/
Behavioral analyses in the lab
Proportion of ACPnot entering chamber
with source of volatiles
Proportion of ACP attractedto chamber with citrusf
Citrus
*Guava
Guava + Citrus
Citrus + Synthetic DMDSCitrus + Synthetic DMDS
100 50 0 50 100Percentage of ACP responding
Biodegradable wax-based controlled-release system
ConclusionsConclusions
G l d DMDS hGuava leaves produce DMDS when mechanically injured.
DMDS is highly toxic to most insect speciesspecies
It is one possible explanation for the repulsive effect of guava on the Asian Citrus Psyllidy
ConclusionsConclusions
G l ACP t itGuava repels ACP response to citrus host plants confirmedThe synthetic compound dimethyl
disulfide (DMDS) identified from Guavadisulfide (DMDS) identified from Guava repels ACP in the laboratory equally to
th ti G l tilauthentic Guava volatilesField trials planned for 2009 p
AcknowledgementsAcknowledgements
This project was funded in part by the Florida Citrusby the Florida Citrus Production Research Advisory Council.
