8th INTERNATIONAL WHEAT CONFERENCE

geNeTIC ANALySIS of STem RuST ReSISTANCe IN BReAd
WheAT ANd deTeCTIoN of ReSISTANCe geNe WITh
muLTI-PAThoTyPeS TeST
M. Khodarahmi 1 , Y. Reihani 2 and F. Afshari 3
1, 2 Islamic Azad University Karaj Branch
3 Seed and Plant Improvement Institute
E-mail Address of presenting author: khodarahmi@kiau.ac.ir
In the present study, virulence structure of 15 stem rust isolates, selected from several
samples collected from different part of Iran was studied using 47 international
standard differential lines. The result showed that, all isolates were virulent on
Sr6῾Sr7a῾Sr7b῾Sr8a῾Sr8b῾Sr9a ῾Sr9b῾Sr9d῾ Sr9e ῾Sr9f ῾Sr9g῾Sr10῾Sr11῾ Sr12῾Sr13῾Sr14
῾Sr15῾Sr16῾Sr17῾Sr19῾Sr20῾Sr21῾Sr23῾Sr25῾Sr28῾Sr31῾Sr32῾Sr33῾Sr34, Sr37῾SrTT3+
Sr10῾SrWLD῾SrH῾SrDP2῾SrGT and SrPL, some on Sr33, Sr36, Sr22, Sr27, but no virulence
was detected for Sr24, Sr5, Sr35 and Sr26+9g. In another study, in order to determine
number of genes and their mode of action, parental generations as well as F1, F2
and both backcrosses obtained from 2 nd EBWYT-514 x Bolani cross were evaluated under
greenhouse conditions with Hamedan race(with virulence on Sr31 and Sr36). EBWYT-
514(OASIS/SKAUZ//4*BCN/3/2*PASTOR) had a high level of resistance to all stem rust
isolates in this study. In generation mean analysis using joint scaling test revealed that, for
all the resistance components, Additive, dominance, and dominance x dominance effects
were significant. Number of genes, calculated using 4 different formulas, were commonly
ranged between 1 to 2. Broad-sense and narrow-sense heritabilities were 98% and 61%,
respectively. Dominance degree for all traits was complete dominance but negative for
Infection type which indicates that dominance is inclined towards parents with lower
Infection type.
Keywords: Wheat, Stem rust, Virulence genes, Genetic analysis
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