Haplotype analysis of molecular markers linked to stem rust resistance genes in Ethiopian improved durum wheat varieties and tetraploid wheat landraces

Type Journal Article - Genetic resources and crop evolution
Title Haplotype analysis of molecular markers linked to stem rust resistance genes in Ethiopian improved durum wheat varieties and tetraploid wheat landraces
Author(s)
Volume 60
Issue 3
Publication (Day/Month/Year) 2013
Page numbers 853-864
URL http://libcatalog.cimmyt.org/download/cis/97577.pdf
Abstract
The recent emergence of wheat stem rust
race Ug99 (TTKSK) and related strains threaten
Ethiopian as well as world wheat production because
they overcome widely used resistance genes that had
been effective for many years. The major cause which
aggravates the ineffectiveness of Ethiopian wheat
varieties against stem rust is the narrow genetic base
on which the breeding for resistance has been founded,
however, little is known about the resistance genotypes
of Ethiopian durum wheat varieties and
tetraploid wheat landraces. The objective of the study
was to identify stem rust resistance genes that are
present in the Ethiopian tetraploid wheat landraces and
improved durum wheat varieties using molecular
markers and assess which genes are effective for
current Ethiopian stem rust races of Puccinia graminis
f. sp. tritici including Ug99. The investigated 58
tetraploid wheat accessions consisted of 32 (Triticum
durum s.l. incl. Triticum aethiopicum Jakubz., Triticum
polonicum) landraces and 22 registered T. durum
varieties released in Ethiopia between 1966 and 2009
and four T. durum varieties from ICARDA. A total of
17 molecular markers (SSR, EST and InDel) linked or
diagnostic for stem rust resistance genes Sr2, Sr13,
Sr22 and Sr35 were used for genotyping. Haplotype
analysis indicated that only few of the Ethiopian
durum wheat varieties carried Sr13. The resistant
variety ‘Sebatel’ showed a haplotype for Sr2 and Sr22
and variety ‘Boohai’ for Sr22, however further
evaluation is needed for the diagnostic value of these
haplotypes. This study is the first report on the
presence of stem rust resistance (Sr) genes in Ethiopian
durum wheat varieties and tetraploid wheat
landraces based on linked or associated molecular
markers. Thus it might help in the identification of
varieties carrying resistant alleles that provide valuable
genetic material for the development of new
improved varieties in further breeding programmes.

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