Marker assisted breeding for striga
resistance in sorghum in Eritrea
By Tadesse Yohannes
Plant breeding and biotechnology
Supervisors:
Dr. E. C. Ngugi
Dr. Santie de Villiers
Presentation content
Introduction
Problem statement
Justification
Objective
Methodology
Expected output
Research project work plan
Research project budget.
Country profile
Eritrea:
 4.5 million.
 123420 sq. km with 12%
cultivable land.
 Six Agro-ecological zones.
 Climate ranges from hot to
cool - rain fall 200 -800 mm.
 Agriculture is the main
economic activity(80%),
contribute 26 % GDP.
ERITREA
Introduction
Sorghum is the fifth most important cereal crop
in the world (FAOSTAT 2004).
It is grown in at least 86 countries, on an area of
45 million ha, with annual grain production of 65
million t and average productivity of 1.45 t ha-1
(FAOSTAT, 2008).
Its origin is in Africa and is critical component
of food security in the continent (Dogget 1988).
Introduction continued
In Africa, annual losses due to striga is
estimated as 4.1 million t which is about US$ 7
billion (Sauerborn 1991), adversely affecting
over 300 million people (Ejeta and Gressel,
2007).
 Manipulation of Striga seed numbers is
central to Striga control.
Development and utilization of Striga
resistant variety through a combination of
conventional breeding and MAB is efficient.
Introduction continued
In Eritrea it is mainly grown for ‘enjera’, porridge,
and local drink ‘siwa’. the Stover for feed, fuel.
Sorghum production in Eritrea is constrained by
several factors.
Striga hermonthica is a major biotic constraint to
sorghum production (Sauerborn,1991).
Problem statement
Productivity is less than 1 t ha-1.
Yield losses due to striga can reach 100% in
western zone of Eritrea (Oblina et al., 2002).
Some arable lands are abandoned because of
striga infestation.
The challenge
Justification
Sorghum is the source of livelihood for many small
scale rural households .
The use of Marker assisted breeding for striga
resistance in sorghum is well proven and tested by
IRC such as ICRISAT(Haussmann et al., 2004) .
Conventional breeding in the transfer of such traits
have been slow , time consuming and complicated
with numerous factors:
• Results may not be accurate and certain until
field tests carried out.
General objective
To improve sorghum productivity in Eritrea by
developing striga resistant sorghum variety.
Specific objectives
1.To genotype segregating populations from a cross
between a donor and FPSV for striga resistance
QTL.
2. Evaluate and identify superior introgressed
sorghum lines resistant to striga.
Research methodology
This project builds on an existing project which
generated BC3F1 introgressed lines
Breeding scheme
FPSV (Hugurtay) X N13 (Donor)
F1 X FPSV (Backcrossing)
BC1F1 X FPSV FG screening
BC2F1 X FPSV FG & BG selection
BC3F1 (FG & BG selection,
selfing, field evaluation)
Methodology continued
Laboratory activities
Leaf samples will be collected for DNA extraction
and analysis.
Extraction will be done at ICRISAT Nairobi lab
using CTAB extraction method of Mace et al.,2004.
 Amplification with SSR markers.
PCR fragment analysis by capillary electrophoresis
Allele size scoring will be done using
GeneMapper® Software V4.
Lines with the desired QTLs will be selected.
Methodology continued
Field activities:
1.Seed increase & selfing
 Introgressed lines with 1- 4 QTLs planted in 1.5m row.
2. Field screening (experiment 1)
 Lines with1-4 QTLs selected through genotyping to be
screened for agronomic performance & striga resistance
in artificial infested plots. Site Alupe.
 Design : augmented design.
3. Field evaluation in replicated trial (expt.2)
 Design: RCBD with four replications.
 Each plot with 5 rows of 3m length.(artificially
Field screening at Alupe, June 29, 2012
Expected outputs
At least one or two striga resistance
introgressed lines identified and evaluated.
Experience on molecular breeding technique
and data analysis gained.
 A Thesis for the degree of MSc.
 At least one article published.
Work plan
ACTIVITIES
YEAR 2012
YEAR 2013
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Proposal writing
X
X
planting, general follow up
X X
Watering, Weeding, bird scaring
X X
Genotyping
X
Thesis write up
Submission of first draft thesis
X
X
X
X
X
X
X X
Harvesting, threshing, cleaning
Data collection and analysis
X
X
X
X
X
X
X
X
X
X
X
X
X
Estimated budget
Activities
Amount
(Kshs)
Lab activities
249,000
Field activities & materials
235,000
Agricultural inputs
5,000
Travel expense
71,000
Thesis writing
10,000
contingency
15,000
Total
585,000
ASANTE SANA