TY  - PRO
AU  - Sukhwinder-Singh
AU  - Dreisigacker,S.|Singh,S.
AU  - Gill,K.S.
AU  - Lopez,E.E.
AU  - Huerta-Espino,J.
AU  - Singh,R.P.
AU  - Bhavani,S.
TI  - QTLs mapping of durable adult plant resistance to stem rust Ug99 of wheat in population PBW343/MUU
SN  - 978-970-648-179-5
PY  - 2011///
CY  - Mexico, DF (Mexico)
PB  - CIMMYT
N1  - Abstract only
N2  - Stem rust, caused by Puccinia graminis f. sp. tritici, is potentially one of the most serious diseases of wheat in several wheat growing regions of the globe. Genetic enhancement for the disease involves the quantitative nature of inheritance, which reflects the additive effects of several genetic loci all over the genome. QTL mapping can offer paved initial points for identifying such candidate genes/ alleles, which can further be used for the introgression-breeding program. The advanced line MUU showed elevated levels of adult plant resistance to stem rust when tested in Kenya for last five years. Recombinant inbred line (RIL) population developed from a cross of resistant parent MUU and susceptible parent PBW343 and field tested in two crop seasons 2009 and 2010 against stem rust pathogen. The distribution of the disease severity in the RIL population varied from highly resistant (less than 10% severity) to susceptible (more than 80% severity) confirming the quantitative nature of the effects of the QTL for resistance. A genetic map of wheat with 492 the Diversity Array Technology (DArT) and 74 simple sequence repeat (SSR) markers was constructed using a population of inbred line (RIL) from a cross between the PBW343 and MUU. Linkage groups were assigned to wheat chromosomes using available map locations of SSR markers as reference points. Inclusive Composite Interval Mapping (ICIM) identified genomic regions associated with low disease severity on chromosomes 2B, 3BS, and 5BL. These genomic regions explained 5- 36% of the phenotypic variation in adult plant stem rust reaction. The QTL identified on chromosome 3BS suggests the contribution of Sr2 in reducing the disease severity. The QTL on chromosome 5BL and 2B explained 5 - 8% of phenotypic variance and was reliable in both the years. Enrichment of chromosome 5BL with more markers will be discussed. The markers within these QTL regions present an opportunity for marker-assisted selection for stem rust in wheat breeding programs
ER  -