Location: Cereal Disease LabTitle: Sources of stem rust resistance in wheat-alien introgression lines
|Rahmatov, Mahbubjon - Swedish University Of Agricultural Sciences|
|Rouse, Matthew - Matt|
|Andersson, Staffan - Swedish University Of Agricultural Sciences|
|Steffenson, Brian - University Of Minnesota|
|Wanyera, Ruth - Kenya Agricultural And Livestock Research Organization|
|Pretorius, Zacharias - University Of The Free State|
|Houben, Andreas - Leibniz Institute Of Plant Genetics And Crop Plant Research|
|Nazari, Kumarse - International Center For Agricultural Research In The Dry Areas (ICARDA)|
|Bhavani, Sridhar - International Maize & Wheat Improvement Center (CIMMYT)|
|Johansson, Eva - Swedish University Of Agricultural Sciences|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2016
Publication Date: 6/1/2016
Citation: Rahmatov, M., Rouse, M.N., Andersson, S., Steffenson, B., Wanyera, R., Pretorius, Z., Houben, A., Nazari, K., Bhavani, S., Johansson, E. 2016. Sources of stem rust resistance in wheat-alien introgression lines. Plant Disease. 100(6):1101-1109. doi.org/10.1094/PDIS-12-15-1448-RE.
Interpretive Summary: Wheat stem rust is a fungal disease of wheat that decreases yield. A strain of the wheat stem rust fungus known as Ug99 emerged in Uganda in 1999 and threatens global wheat production because it is able to infect nearly all wheat varieties. We assessed the stem rust resistance in a collection of hybrid wheat lines created through crossing wheat with related species. This collection of lines was from the Swedish University of Agricultural Sciences. We found several of these hybrid lines that possessed resistance to Ug99. Three lines were identified that we postulated to have new resistance to Ug99 based on their their resistance to a broad spectrum of stem rust pathogen races. The identification these new resistance sources will facilitate the improvement of resistance of worldwide and United States wheat cultivars to the dangerous Ug99. Multiple sources of resistance are needed because of the ability of Ug99 to become virulent to singly-deployed resistance genes. Ug99 resistant wheat cultivars will protect global and United States wheat production from yield loss if a Ug99 epidemic were to occur in the United States.
Technical Abstract: Stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most devastating diseases of wheat and the novel highly virulent race of TTKSK and its lineage are threatening wheat production worldwide. The objective of the study was to identify new sources of resistance in wheat-alien introgression derivatives from Secale cereale, Leymus mollis, Leymus racemosus and Thinopyrum junceiforme, to postulate the genes behind the resistance, and to verify the postulated genes by use of molecular markers. From the seedling tests, the presence of seven known stem rust resistance genes, Sr7b, Sr8a, Sr9d, Sr10, Sr31, Sr36 and SrSatu were postulated in the evaluated wheat-alien introgression lines. More lines possessed a high level of resistance in the field compared to the number of lines that were resistant at the seedling stage. Three lines, SLU210, SLU238 and SLU239 were found most likely to possess new gene/s for resistance to stem rust according to their resistance pattern to 13 different stem rust races. Wheat-rye, wheat-L. racemosus and wheat-L. mollis substitutions and translocations with single and multiple interchanges of chromosomes, in particular of the B and D chromosomes of wheat, were verified by a combination of GISH and molecular markers. Thus, the present study identified novel resistance sources originating from different alien introgressions into the wheat genomes of the evaluated lines, and therefore we recommend further evaluation and exploitation of the most promising introgressions.