8th INTERNATIONAL WHEAT CONFERENCE

SCReeNINg ANd BReedINg foR WheAT STem RuST
ReSISTANCe IN eAST AfRICA
D. Singh 1 , P. Njau 2 , B. Girma 3 , S. Bhavani 4 , R.P. Singh 4 ,
R. Wanyera 2 , A. Badebo 3 , S. Gelacha 3 , G. Woldeab 3 ,
J. Huerta-Espino 5 , M. Gethi 2 , H-J. Braun 4 and G. Cisar 6
1 CIMMYT, Nairobi, Kenya
2 Kenya Agricultural Research Institute- Njoro, Kenya
3 Ethiopian Institute of Agricultural Research, Ethiopia
4 CIMMYT, Apdo. Postal 6-641, 06600, Mexico, DF, Mexico
5 INIFAP-CEVAMEX, Apdo. Postal 10, 56230, Chapingo
6 College of Agriculture & Life Sciences, 252 Emerson Hall, Cornell University, Ithaca, NY
14853, USA
E-mail Address of presenting author: dav.singh@cgiar.org
The ability of the world’s farmers to meet current and future demand for wheat is gravely
threatened by the highly virulent stem rust population (Ug99) emerging from East Africa.
The Borlaug Global Rust Initiative (BGRI) established the East Africa stem rust screening
program to manage stem rust epidemics in Kenya and Ethiopia, and to also mitigate the
global threat of virulent and dangerous rust races originating from this region. The program
launched stem rust screening facilities at two sites – Njoro, Kenya Agricultural Research
Institute (for bread wheat); and Debre Zeit, Ethiopian Institute of Agricultural Research (for
durum wheat). Both facilities cater for two cycles per year and have strategic advantage of
climate, environment and location to integrate international screening with shuttle breeding
by CIMMYT, ICARDA, NARS and other organizations. The established critical facilities are
high caliber components of an integrated world effort to minimize the destabilizing effects
of rusts on world wheat production and food security. Wheat-producing nations globally
(more than 50 collaborators from over 30 countries) have participated in wheat stem rust
screening at these two sites. More than 100, 000 research plots in Kenya and Ethiopia have
been screened since 2005 but a low frequency of resistant entries were identified and more
than 80% of screened germplasm was found to be susceptible to the Ug99 stem rust lineage.
Nevertheless, resistance was also identified among international germplasm and CIMMYT
has made a good progress in identifying diverse sources of resistance to Ug99 and its variants
including minor gene adult plant resistance (APR). More than 300 germplasm sets in
the form of four stem rust resistance screening nurseries (1 st to 4 th SRRSN) were distributed.
A high proportion of lines (44%) in these three nurseries have shown good to moderate levels
of resistance in at least two seasons of evaluation in Kenya. Several promising lines with
superior agronomic traits and resistance to the Ug99 lineage have been identified, and are
under further evaluation for use in breeding programs world-wide, or for direct release and
registration in Kenya and Ethiopia, and other counties including Afghanistan, Bangladesh,
Egypt, India, Nepal and Pakistan.
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