Inheritance of Slow Leaf-rusting Resistance in Suwon 85 Wheat1
- Roger C. Kuhn,
- H. W. Ohm and
- G. Shaner2
The inheritance of slow leaf-rusting resistance of the wheat (Triticum aestivum L. em. Thell) cultivar ‘Suwon 85’ was studied in crosses with susceptible cultivars ‘Monon’ and ‘Suwon 92.’ Plants were grown in the greenhouse and inoculated with Puccinia recondita Rob. ex Desm. f. sp. tritici. Two components of slow leaf-rusting resistance, latent period and pustule size, were measured. The distribution of Suwon 85/Suwon 92 F3 family mean latent period indicated partial dominance for short latent period, but gave little evidence of distinct classes. A model that assumed two genes with equal effect and an equal degree of dominance (0.6) for shorter latent period was constructed from earlier data. F3 families were classified into F2 genotypes based on the family mean, range and apparent segregation. The resulting classification gave an acceptable fit to the two gene model. Thus, a lack of distinct classes in an F2 distribution should not be interpreted as proof of polygenic inheritance. Pustule size was correlated with latent period in the F3 (r = −0.55 to −0.63) but there were genetic differences between F3 families for pustule size even after adjustment for latent period differences. F1 and BCF latent period data from the cross Suwon 85/Monon appeared to fit the two gene model described above, but population size was too small to adequately confirm this model.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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