Performance of CIMMYT germplasm in Ethiopia: Key materials for variety development
CIMMYT wheat germplasm flow to Ethiopia started in the late 1960s. Over 90 bread wheat varieties were released over the decades. Of these, about 77% had CIMMYT origins or were derived from CIMMYT materials. Wheat is a traditional rainfed crop grown by 5 million small-scale farmers on 1.6 ha more or less. Yields have increased from 1.0 t/ha in the 1960s to 2.54 t/ha in 2014 mainly due to high yielding semi-dwarf bread wheat varieties and modern agronomic practices. Using such technologies, better farmers often get 5-6 t/ha. The rusts are the most important production constraints. For example, the 2010 yellow rust epidemic debilitated the mega varieties Kubsa and Galama in the highlands. In 2013/14, stem rust caused up to 100% yield losses in the widely adopted bread wheat variety Digalu in Arsi and Bale. This epidemic was caused by Pgt race TKTTF, which is virulent to the gene SrTmp that is present in Digalu, but is avirulent to Sr31, which is overcome by race Ug99 (TTKSK) and derivatives. To avert the increasing threat of rusts, CIMMYT developed a shuttle breeding program where germplasm moves back and forth between Mexico and Kenya and has increased nursery testing sites (Holetta, Kulumsa, Debre Zeit, Sinana, Adet, and Melkassa) in Ethiopia from two to six. The germplasm passes through rigorous tests against major diseases during both the main- and off-seasons. To obtain high yielding rust resistant germplasm, many hundreds of genotypes were introduced and tested over the last two years. In 2014/15, 266 (25%) lines with multiple disease resistances and high yield were promoted to national trials. CIMMYT continues to be an important source of germplasm. Fast tracked variety testing and release, accelerated seed multiplication, demonstration and popularization of new varieties with high yield, multiple disease resistance, and acceptable quality will continue.