|Kim, Yong-Ki - KSU - PLANT PATHOLOGY|
|Cox, Thomas - LAND INSTITUTE - KANSAS|
|Bockus, William - KSU - PLANT PATHOLOGY|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 5, 2004
Publication Date: May 1, 2004
Citation: Kim, Y., Brown Guedira, G.L., Cox, T.S., Bockus, W.W. 2004. Inheritance of resistance to stagonospora nodorum leaf blotch in kansas winter wheat cultivars. Plant Disease. 88:530-536. Interpretive Summary: Stagonospora nodorum blotch (SNB) can cause serious yield and quality losses of wheat in many countries worldwide. Although there are other control methods, growing resistant varieities is the most desirable. Three recent Kansas winter wheat cultivars (Betty, Heyne and 2163) have been developed with moderate levels of resistance to Stagonospora nodorum leaf blotch. It is important to know the mode of inheritance of resistance to this disease in order to effectively use these sources to develop new SNB resistant wheat cultivars. Our research determined that the varieties Heyne and Betty have different genes for SNB resistance. The simple genetic control of resistance in the variety Betty makes it a useful source of resistance for wheat breeding programs.
Technical Abstract: Stagonospora nodorum blotch (SNB) can cause serious yield and quality losses of wheat (Triticum aestivum) in many countries worldwide. Although there are other control methods, host resistance is the most desirable. Three recent Kansas winter wheat cultivars (Betty, Heyne and 2163) have been developed with moderate levels of resistance to the leaf phase of SNB. To determine inheritance of resistance and allelism, these cultivars were crossed with one of three susceptible lines (Larned, KS96WGRC39, or Newton) and intercrossed in all possible combinations, including reciprocals. The parents, F1, F2, and F3 generations were screened in the greenhouse as 4-week-old seedlings. Cytoplasmic effects were not detected in any cross. The mean levels of SNB infection in the F1s of the two crosses Betty x Larned and Heyne x KS96WGRC39 indicated resistance was dominant. The observed phenotypic ratios of F2 plants for both crosses were not significantly different from the expected ratio for a single dominant gene. The observed ratio of F3 lines in the Betty x Larned cross fit that expected for a single dominant gene. However, the observed ratio of the F3 lines from the cross Heyne x KS96WGRC39 did not fit the ratio expected for a single dominant gene. The allelism test for Betty and Heyne indicated that they have different resistance genes. The F1 mean rating of the cross 2163 x Newton was intermediate between the two parents, indicating the absence of dominance for resistance in 2163. The phenotypic ratio observed in the F2 plants from this cross did not fit the ratio expected for a single dominant gene. The simple genetic control of resistance in the cultivar Betty makes it a useful source of resistance for wheat breeding programs.