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Passion fruit work in Uganda. M O Ssemakula 1 , V Aritua 2 , R Edema 1 , T Sengooba 3 , J J Hakiza 2 , J Tumwine 2 , S Kyamanywa 1 & E Adipala 4 . 1 Department of Crop Science, Makerere University, Uganda. 2 NaCRRI, National Agricultural Research Organization, Uganda. - PowerPoint PPT Presentation
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Passion fruit work in Uganda
M O Ssemakula1, V Aritua2, R Edema1, T Sengooba3,
J J Hakiza2, J Tumwine2, S Kyamanywa1 & E Adipala4.
1Department of Crop Science, Makerere University, Uganda.2NaCRRI, National Agricultural Research Organization, Uganda.
3IFPRI, Kampala, Uganda.4RUFORUM, Kampala, Uganda.
Background
The crop: Passion fruit• Is a major export crop from Uganda to the
European market.
• Is mainly grown by small-scale farmers in the Eastern and Western highlands of Uganda.
• Was cultivated on a large-scale in Central Uganda between 1990-2000 as part of the export diversification initiative of the Ugandan Government.
• Earned Uganda US$ 100,000 from the export of 50metric tons at the peak of production in 1998.
Background
The problem: Reduced productivity
• Since 2000, fluctuations in production and export have been realized.
• By 2005, only 7tons of fresh fruit were being exported from Uganda.
• Reduction in production has been attributed to biotic and management-related factors first identified in feasibility and market-oriented studies from 1989-1993.
Background
Limiting factors to production & export:
• Pests and diseases.
• Limited commercial germplasm pool:• Dominated by a single variety, the Kawanda Hybrid.
• Kawanda Hybrid is susceptible to prevalent pests and diseases.
• Poor agronomic and post harvest practices, thus:• Variability in the quality of produce.
• Fruit damage.
Background
Diseases:
• Are the most significant biotic constraint to passion fruit production in Uganda.
• Priority diseases include:• Brown spot.
• Collar rot.
• Viral diseases.
Background
Management of priority diseases:
• Brown spot:• Mainly occurs in warm, humid production
areas.
• Is currently being managed using the fungicide Ridomil (Dithane M45), which controls disease incidence and severity (Ssonko et al. 2005).
Background
Management of priority diseases:
• Collar rot:• Introduction of improved germplasm from external
sources (Campbell 1992, NARO 1994).
• Grafting of Kawanda Hybrid to tolerant local yellow rootstock (Ssekyewa 1993, NARO 1998, ADC/IDEA 1999).
• Screening of local yellow and sweet calabash (hard-shelled) passion fruit types for disease tolerance, with some success in screen house trials (NARO, 2006).
Background
Management of priority diseases:• Viruses:
• Retrieval of Kawanda Hybrid clones 5, 6, 7 and 8, previously lost from the Horticultural Program (NARO 1994, ADC/IDEA 1999).
• Dissemination of clean planting material to farmers (MAAIF 1990, NARO 2000, ADC/IDEA 2000, 2002).
• Identification of the causal agent as a potyvirus similar to passion fruit woodiness virus (PWV) and cowpea aphid-borne mosaic virus (CABMV).
Background for IPM CRSP Work
Impact of management efforts for viral diseases was not felt because:• Data on disease epidemiology was not
adequate enough for appropriate management strategies to be formulated.
• Causal agents were not fully identified while widespread variation in disease distribution was suggestive of multiple species or strain occurrence.
• No sources of tolerance were identified to counteract the susceptibility of commercial germplasm.
Background
Viral diseases on passion fruit, therefore escalated since the cultural measures in use were ineffective in disease management.
A research program on passion fruit viruses was then initiated at Makerere University to:• Map viral disease incidence and severity.
• Identify and characterize viral pathogens.
• Characterize and screen local passion fruit germplasm for sources of host tolerance to viruses.
Disease mapping
Two disease surveys were conducted in 15 major passion fruit-growing districts of Uganda during November 2003 and May 2005.
Data on disease incidence and severity were collected and mapped using Geographical Information System (GIS) software (Ilwis 3.1 and ArcView 3.2).
Map to show incidence of viral diseases on passion fruit in
Uganda
D.R.C KENYA
SUDAN
TANZANIARWANDA
Lake Victoria
2
1
3 4
5
6
7
8
9
10
11 12
13
15
14
0 200 Kilometers
N
EW
S
250000
250000
500000
500000
750000
750000
0 0
250000 250000
Incidence scale
4 - 1516 - 2728 - 3839 - 5051 - 6162 - 73
Kabarole (1)
Kasese (2)
Bushenyi (3)
Mbarara (4)
Mubende (5)
Mpigi (6)
Masaka (7)
Apac (8)
Nakasongola (9)
Luwero (10)
Wakiso (11)
Mukono (12)
Iganga (13)
Mbale (14)
Sironko (15)
Pathogen identification
The Ugandan Passiflora potyvirus has been identified:• As a novel potyvirus species on passion fruit:
• With AA motifs associated with aphid-transmission.
• With biological similarity to CABMV, passion fruit ringspot virus and PWV
• Distinct from PWV, CABMV and other viruses causing passion fruit woodiness disease worldwide such as Cucumber mosaic virus and East Asian Passiflora virus.
Alignment of partial virus coat protein for the Uganda Passiflora
potyvirus against known potyviruses and other viruses on
passion fruit worldwide UGM-19 1 S--GK----- KDEEIDAGKD ---KEKSKEQ KNTEQPG--- -RV------- --TSTPPTSIUGM-58 1 S--GK----- KDEEIDAGKD ---KEKSKEQ KNTEQPG--- -RV------- --TSTPPTSIUGM-73 1 S--GK----- KDEEIDAGKD ---KEKSKEQ KNTEQPG--- -RV------- --TSTPPTSIPV-0707 1 S--GK----- KDEEIDAGKD ---KEKSKEQ KSTEQPG--- -RV------- --TSTPPTSIUGM-17 1 S--GK----- KDEEIDAGKE ---KEKNKEQ RSVERTE--- -KL------- --TLSSAANTBCMV-Y 1 S--GT--GQP QPPIVDAGVD ---AGKDKRE RSNRGKD--- -PEGREGSGN NNRGAGDSTMTCY-8648 1 S--GT----G VVEGIDAGVD ---SRKKKQV EESSKNV--- -AE------- ----PEIIDHPWV-CL1 1 S--GSMSGKD KDETLDAGGD ----GK---- RSTGKKA--- -AEG--SGGD SRKKSEEDTTPWV-6715 1 S--GSMSGKD KDETLDAGGD GKRSTGKKTA EGSGGDS--- -RK------- ---KSEEDTTPWV-M3 1 SDG------- KDKELDAGKD ---KEKDKEA KEQSVQQ--- -KQ------- --AKNKGAKECABMV-Z 1 SDE------- RQKELDAGKD ---KDKAKEA REQSTQQ--- -KQ------- --AKNKGAKECABMV-Ib 1 SGR------- RQEELDAGQD ---KDKGKEG TEQSTQQ--- -K-------- --TKKKGINECAB-SAPV 1 SGR------- KQEELDAGKD ---KEKTKEG EEQSTQQ--- -KQ------- --TKDKGTKEEAPV-AO 1 TKSEENKDEL GKDAIDAGND GKRKDKEKE- --GMVTP--- -PTNPNPNNS KFG-GSSFNREAPV-IB 1 SSTGKDKEEE SKDTIDAGGD GGRKDKEKEK RTGTLAT--- -LENPNPINP NGGDGSSLGRPVY-2567 1 MA-------- -NDTIDAVES NKKESKPEQG SIQSNSN--- -KG------- ----------PLV-0082 1 M-----PPKE APEVVPPPVP PPLPMKEKEA SSSSEPNDEE LRQRRLLKLI EILQAQNHNSMSV-A(Km) 1 MSTSKR---- -----KRGDD SNW----SKR VPKKK----- --------PS SAGLKRAGSKOFV-2444 1 MANPSEIDYM TPLSAYEGVP AEYQEATSSP TPKEYTRDAA KAIPICILPA PPGNEVEVAEOKMV-0352 1 M--------- ---------- ---------- ---------- ---------- ----------TYLC-0601 1 M--------- ---------- ---------- ---------- ---------- --------SKTORS-6765 1 W--------- ---------- ---------- ---------- ---------- ----------CMV-RT52 1 M--------D KSGSTSAGRN RRRRPRRGSR SAPSSADANF RVLSQQLSRL NKTLAAGRPTMARM-3569 1 M--------- ---------- ---------- ---------- ---------- ----------
Phylogeny of the Ugandan Passiflora virus
PWV-Au2
PWV-CL1
CABMV-Z
CABMV-SAP
PWV-M3*
CABMV-Ib
EAPV-AO
TCY-8648
BCMV-Y
UGM-17-3
UGM-19a-4
PV-0707
UGM-73-10
UGM-58-1
PVY-NTN
PVY-2567
TYLC-060
CMV-RT52
OKMV-035
MARM-356
TORS-676
OFV-2444
PLV-0082
MSV-A (Km)
100
75
100
32
27
90
98
9
23
17
9280
52
35
42
85
18
15
11
28
0.05
Passion fruit woodiness virus
Cowpea aphid-borne mosaic virus
East Asian Passiflora virus
Ugandan Passiflora virus
Representative isolates for other viruses reported on passion fruit worldwide
Genetic similarity analysis
Amino acid identity values (%) Species-isolate
UGM-17 UGM-19 UGM-58 UGM-73 PV-0707 UGM-17* - - - - - UGM-19* 88 - - - - UGM-58* 88 100 - - - UGM-73* 88 100 100 - - PV-0707* 87 98 98 98 - PVY-NTN* 56 56 56 56 56 BCMV-Y* 73 73 73 73 72 PWV-CL1* 71 71 71 71 70 PWV-6715* 61 62 62 62 61 CABMV-Z* 74 73 73 73 72 CABMV-Ib* 73 75 75 75 74 CABMV-SAP* 76 76 76 76 76 EAPV-AO* 72 73 73 73 72 PLV-0082 7 9 9 9 9 TYLCV-0601 3 2 2 2 6 CMV-RT52 3 1 1 1 7 OFV-2444 5 4 4 4 5 OkMV-0352 3 3 3 3 2 MarMV-3569 5 12 12 12 12 TORSV-6765 4 5 5 5 5
Virus characterization
Host assays using 26 plant species in Nicotiana, Chenopodium, Datura and Passiflora:• Revealed variability across virus isolates:
• Host range.
• Severity of infection.
Germplasm Characterization
Sixty accessions of 5 passion fruit types were collected from farmers’ fields.
Morphological characterization done in 2005B and 2006A:• High variability in phenotypic traits for
germplasm within and between locations.• Plants with beneficial qualitative and
quantitative traits were identified.
Morphological characterization of passion fruit in Uganda: Field
trial
Morphological characterization of passion fruit in Uganda: Screen
house trial
Molecular characterization
Simple sequence repeat (SSR) markers:• Not polymorphic enough across species.
Random amplified polymorphic DNA (RAPD) markers:• Currently under evaluation.
• Preliminary results reveal genetic diversity within and across species.
Germplasm screening for virus tolerance
Experiment: • Completely Randomized Design in a screen house
trial.
• Double graft technique for plant inoculation.
• Six accessions of yellow, hard-shelled and sweet granadilla types were grafted to 4 virus isolates maintained on passion fruit.
• Data collected from 30 days after second grafting, for a duration of 5 months.
• Data type: Disease severity and virus titre (ELISA).
Graft inoculation of passion fruit
ANOVA for tolerance of graft inoculated passion fruit seedlings
to viral infectionCHANGE DF SS* MS* VR* F. PR.
Virus titre 1 7.3 7.3 8.2 0.006
Week after Grafting (WAG)
6 68.1 11.4 12.7 <0.001
Virus isolate 3 13.2 4.4 4.9 0.004
Germplasm 5 28.2 5.6 6.3 <0.001
WAG X Isolate 16 31.1 1.9 2.2 0.018
WAG X Germplasm 24 25.2 1.1 1.2 0.309
Isolate x Germplasm 3 1.8 0.6 0.7 0.587
WAG X Isolate X Germplasm
7 6.6 0.9 1.1 0.408
Residual 52 46.6 0. 9
Total 117
228.1 1.9*Values were rounded off.
Summary of disease data for passion fruit germplasm
screening trial under screen house conditions in Uganda
Most tolerant:• Germplasm 3 & 4.• Not important
commercial types currently.
• Have potential for breeding purposes.
WAG Germplasm accession Mean severit
y1 2 3 4 5 6
4 1.06
1.02
1.01 1.04
1.03
1.01
1.02
6 3.62
5.05
2.32 - 4.50
4.54
3.34
8 2.74
3.99
1.82 - 3.97
3.22
2.46
10 1.92
3.03
1.55 1.01
0.94
3.91
2.25
11 2.64
3.99
2.85 0.99
- 3.60
3.03
14 3.97
2.96
2.29 1.96
- 3.63
2.83
16 3.69
2.99
1.96 - - 3.26
2.60
Mean 2.36
2.87
1.84
1.15
2.43
3.09
LSD (0.05)
1.7841.09
CV (%)
Partners
Funding:• Innovations at Makerere Program (Rockefeller Foundation/
World Bank).• International Foundation for Science.• Faculty of Agriculture (Sida-SAREC and NORAD grants).
Technical support/Collaboration:• Deutsche Sammlung von Mikroorganismen und Zellkulturen
(DSMZ), Germany.• National Agricultural Research Organization (NARO):
• National Crop Resources Research Institute (NaCCRI):• Horticultural Research Program (NHRP).
• National Agricultural Research Laboratories:• Agricultural Biotechnology Centre (NABC).
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