8th INTERNATIONAL WHEAT CONFERENCE

Volga regions to 54% in the Noth Caucasian region. The highest and lowest molecular
diversity were within the Volga (KW m = 0.308) and Noth Caucasian (KW m = 0.080) collections,
respectively, while intermediate values of diversity within the North Western,
Central, Black Earth, West Siberian and Ural regions (KW m = 0.154, 0.173, 0.132, 0.097
and 0.141, respectively) also differed significantly. According to the molecular markers
data and genetic distance KB m , the Volga leaf rust collection was the most distant from
all other regional populations, but small number of the isolates tested does not allow a
valid assessment of the corresponding parameters. Other six populations were separated
in two distinct groups of relatively resembling collections from the North Western, North
Caucasian and West Siberian regions, and from the Central, Black Earth and Ural regions.
The virulence and molecular markers data provided different pictures of relationships
between the regional collections of wheat leaf rust. The similarity in the genetic backgrounds
of the isolates, as assessed by molecular markers for some populations, suggest
that observed differences in pathogenicity may have arisen by selection for specific virulences
corresponding to genes for resistance in wheat cultivars grown in regions. The
molecular results also support a hypothesis of long-distance migration of urediniospores
of P. triticina in Russia. The low sensitivity of used type of markers to fine levels of genetic
variation might misrepresent actual relationships between the regional collections. For
consolidation of the reported results and conclusions future studies with more effective
molecular markers are required.
The studies were conducted under financial support by Russian Foundation for Basic Researches
(grant №07-04-01455а). Collaboration between Russian and Israeli researchers
was initiated thanks to the travel grant of Israeli Academy of Sciences and Humanities.
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