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United States Department of Agriculture

Agricultural Research Service

Title: Geographic Distribution of Common and Dwarf Bunt Resistance in Landraces of Triticum Aestivum Subsp. Aestivum

Authors
item Bonman, John
item Bockelman, Harold
item Goates, Blair
item Obert, Donald
item Mcguire, Patrick - UNIV OF CA, DAVIS, CA
item Qualset, Calvin - UNIV OF CA, DAVIS, CA
item Hijmans, Robert - INTL RICE INST, MANILA

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 13, 2006
Publication Date: May 18, 2006
Citation: Bonman, J.M., Bockelman, H.E., Goates, B., Obert, D.E., Mcguire, P.E., Qualset, C.O., Hijmans, R.J. 2006. Geographic distribution of common and dwarf bunt resistance in landraces of triticum aestivum subsp. aestivum . Crop Science.

Interpretive Summary: Landrace accessions of cultivated bread wheat (Triticum aestivum L. subsp. aestivum) (TAA) from the USDA-ARS National Small Grains Collection (NSGC) have been tested systematically for the past 25 years for disease resistance. We analyzed the resistance of 10759 TAA accessions to common bunt (CB), caused by Tilletia tritici (Bjerk.) Wint. and T. laevis Kühn, and 8167 for dwarf bunt (DB), caused by T. controversa Kühn with respect to (i) geographic origin, (ii) relationship to color of awn, glume, and kernel of accessions, and (iii) phenotypic variation within areas of high incidence of resistance. A clear “center of concentration” was evident for CB resistance extending from Serbia and Montenegro through Macedonia, Turkey, and Iran with the highest incidence of resistance occurring in Kosovo province in Serbia and Montenegro (36%) and Bakhtaran province in Iran (40.8%). Compared to CB resistance (5.5% of total tested), DB resistance was more rare (1.3% of total tested). DB resistance was concentrated in accessions from Iran, Turkey, and Serbia and Montenegro with the highest incidence of resistance (58%) occurring in Hakkari province in southeastern Turkey. CB resistance was positively associated with lightly pigmented kernels and negatively associated with lightly pigmented awns and glumes, whereas relatively little association was evident between these traits and DB resistance. Analysis of accessions from areas with unusually high incidence of resistance suggested that DB resistant accessions from Hakkari are genetically diverse, whereas CB resistant accessions from Bakhtaran may be much less so.

Technical Abstract: Landrace accessions of cultivated bread wheat (Triticum aestivum L. subsp. aestivum) (TAA) from the USDA-ARS National Small Grains Collection (NSGC) have been tested systematically for the past 25 years for disease resistance. We analyzed the resistance of 10759 TAA accessions to common bunt (CB), caused by Tilletia tritici (Bjerk.) Wint. and T. laevis Kühn, and 8167 for dwarf bunt (DB), caused by T. controversa Kühn with respect to (i) geographic origin, (ii) relationship to color of awn, glume, and kernel of accessions, and (iii) phenotypic variation within areas of high incidence of resistance. A clear “center of concentration” was evident for CB resistance extending from Serbia and Montenegro through Macedonia, Turkey, and Iran with the highest incidence of resistance occurring in Kosovo province in Serbia and Montenegro (36%) and Bakhtaran province in Iran (40.8%). Compared to CB resistance (5.5% of total tested), DB resistance was more rare (1.3% of total tested). DB resistance was concentrated in accessions from Iran, Turkey, and Serbia and Montenegro with the highest incidence of resistance (58%) occurring in Hakkari province in southeastern Turkey. CB resistance was positively associated with lightly pigmented kernels and negatively associated with lightly pigmented awns and glumes, whereas relatively little association was evident between these traits and DB resistance. Analysis of accessions from areas with unusually high incidence of resistance suggested that DB resistant accessions from Hakkari are genetically diverse, whereas CB resistant accessions from Bakhtaran may be much less so.

Last Modified: 11/26/2014
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