sweetpotato regional breeding for east and central africa · 2020-01-22 · sweetpotato breeding...
TRANSCRIPT
Sweetpotato Regional Breeding for East and Central Africa
R. Mwanga, S. Tumwegamire, Sammy Agili, W. Gruneberg, J. Low, G. Ssemakula, E. Tsegaye, P. Ndolo, L. Karanja, E. Lukonge
R. Amour, J. Ndirigwe
Outline
Recent sweetpotato breeding
activities in E. & Central Africa
Example of sweetpotato breeding
cycle, Uganda
East and Central Africa
support platform breeding activities
Accelerated breeding
Sweetpotato Breeding Activities
Previously Supported by HarvestPlus
HP Meeting 2003, CIAT, Cali, Colombia
Introduced 40 OFSP In Vitro Clones to SSA
plus seed
Target total 10 countries from West, South and
Central Africa.
OFSP Clones Released/Grown in Sub-Saharan Africa
*
**
Uganda
(Namulonge, Serere)
*
*
*
*
Zanzibar
*
*
Gurue
Kibaha
Angoni
Umbelezi
Hombolo
Bukoba
Mandoto**Mimosa
*
Kenya
(Kakamega)
*Rwanda (Rubona, Kibundo)
Madagascar
TZ
SA
GH
MO
**
Regional GxE OFSP 15 Trial Sites, 2006/2007
Breeding programs
introduced and
produced seed
(open pollinated
and specific
crosses) for
screening, selection
and exchange
Exchange of Sweetpotato Seed
6 Released in 1999 2 Released in 2004
5 Released in 2007 NASPOT 11 Released in 2010
Twenty Varieties Released by the Sweetpotato Breeding
Program in Uganda, 1995-2010 (Mwanga et 2009, 2010)
Local, Introduced &
Improved Germplasm & Breeding lines
Crossing Block (Polycross)
Clonal Evaluation (Yr 2)
2,000 Clones (No Reps)
Seedling Nursery (Yr 1)
100,000 Seedlings
Preliminary Yield Trial (Yr 3)
100 Clones (Replicated)
Intermediate
Yield Trial (Yr 4)
50 Clones (Replicated)
Advanced / Multi-Location
Trials (Yrs 5,6) 25 Clones
Replicated
On-farm Trials (Yr 7) 5
Clones (Replicated
Variety Release (Yr 8)
Sweetpotato
Breeding
Scheme
Uganda
Sweetpotato Weevil Damage
Losses can reach 100%
during dry periods
To date no durable resistance
Sweetpotato virus
disease (SPVD) can cause up 98% yield loss
(Gibson et al. 1998)
SP chlorotic stunt virus SP feathery mottle virus
Sweetpotato Support Platform (SSP) Breeding
Activities• Population (P)
improvement by SSP –
long term (SASHA)-
use distinct
populations to lead to
major improvements
(heterosis) in e.g. yield,
disease resistance
•Variety (V)
improvement by
sweetpotato National
programs – short term
(AGRA or other
support)
Population improvement
SASHA Project
Accelerated Breeding
Multiply new breeding lines in
screenhouses, glasshouses,
irrigated fields
Accelerated Breeding
•Use more sites at
earlier stages in the
breeding cycle to
substitute for fewer
sites over seasons
Kachwekano
Namulonge
Serere
Ngetta
Trial Sites in
Uganda
Confirming Resistance to Viruses
Complex and tedious
Identify Gene/Marker and Verify
Marker
Sequence
Compare to
known sequences
Specific
Primers
(rkn1f, rkn1r))
Confirm
QTL
Testing in other
Progeny or
clones
Use marker for
selecting resistant
clones (MAS)
pCIP84
14602 bp
kanamycin (R)
nptII
Cry7Aa1
Cry3Ca1
T-BORDER (R)
pVS1 Sta
T BORDER (L)
pBR322 bom site
POLY A SITE
gSPOA1 promoter
nos P
B-amyl
pBR322 ori
pVS1-REP
TATA box
T35S
3' beta-amy
3' gSPOA1
Introduce Weevil Resistance
Genes into Sweetpotato Using
Biotechnology
END