Summary
Experiments in which a series of host cultivars are inoculated in all combinations with a series of pathogen isolates have been used to detect specificity in the host resistance. A theoretical model of polygenic resistance involving both general and specific interactions with pathogen virulence was developed to test the abilities of statistical analyses to discriminate between host genotypes with different levels of general and specific resistance. Estimates of levels of specific resistance could be obtained in regressions of disease severity scores for each host cultivar X pathogen isolate combination vs. the virulence index of each isolate. If the virulence index was based on the mean disease severity induced by the isolate over all host cultivars, the slopes of the regression lines were correlated with the levels of specific resistance in host cultivars. If the virulence index was based on the disease severity induced by the isolate on a host cultivar with a minimum of specific resistance, the mean squares for deviations from the regression were correlated with the levels of specific resistance in host cultivars. A method was developed to consistently choose host cultivars with minimum specific resistance. The two regression analyses gave estimates of specificity in randomly generated, model genotypes of approximately equal accuracy, although the second method appeared to be more accurate when the numbers of loci controlling resistance and virulence were small. The best estimates of numbers of genes for specific resistance were obtained by calculating a rating based on mean disease severity, the mean square for deviation from the regression on the virulence index based on disease severity on the cultivar with minimum specific resistance and the slope of the regression on the virulence index based on the mean disease severity. The best estimates of proportions of resistance genes that were specific were obtained by calculating a rating based on the above deviation mean square and slope alone.
Similar content being viewed by others
Literature
Caten, C.E. (1974): Intra-racial variation in Phytophthora infestans and adaptation to field resistance for potato blight. Ann. Appl. Biol. 77, 259–270
Clifford, B.C.; Clothier, R.B. (1974): Physiologic specialization of Puccinia hordei on barley hosts with non-hypersensitive resistance. Transact. Brit. Mycol. Soc. 63, 421–430
Eberhart, S.A.; Russell, W.A. (1966): Stability parameters for comparing varieties. Crop Sci. 6, 36–40
Flor, H.H. (1971): Current status of the gene-for-gene concept. Ann. Rev. Phytopathol. 9, 275–296
Hamid, A.H.; Ayers, J.E.; Hill, R.R., Jr. (1982): Host X isolate interactions in corn inbreds inoculated with Cochliobolus carbonum race 3. Phytophathology 72 (in press)
Johnson, R. (1978): Practical breeding for durable resistance to rust diseases in self-pollinating cereals. Euphytica 27, 529–540
Leonard, K.J.; Moll, R.H. (1981): Durability of general resistance: Evaluation of cultivar x isolate interactions. Proc. Symposia, IX Inter. Congr. Plant Protection, Washington, D.C., USA, August 5–11, 1979. Vol. I, 190–193
Milus, E.A.; Line, R.F. (1980): Characterization of resistance to leaf rust in Pacific Northwest wheats. Phytopathology 70, 167–172
Parlevliet, J.E. (1976): Evaluation of the concept of horizontal resistance in the barley/Puccinia hordei host pathogen relationship. Phytopathology 66, 494–497
Parlevliet, J.E.; Zadoks, J.C. (1977): The integrated concept of disease resistance, a new view including horizontal and vertical resistance in plants. Euphytica 26, 5–21
Robinson, R.A. (1976): Plant pathosystems. Berlin, Heidelberg, New York: Springer
Singh, S.P.; Jotwani, M.J., Rana, B.S.; Rao, N.G.P. (1978): Stability of host plant resistance to sorghum shoot fly Athengona saccata (Rondanl). Indian J. Entomol. 40, 376–383
Vanderplank, J.E. (1963): Plant disease: Epidemics and control. New York: Acad. Press
Vanderplank, J.E. (1968): Disease resistances in plants. New York: Acad. Press
Author information
Authors and Affiliations
Additional information
Communicated by G. S. Khush
Cooperative investigation of the U.S. Department of Agriculture, Agricultural Research Service and the North Carolina Agricultural Research Service. Journal Series Paper No. 8326 of the North Carolina Agricultural Research Service
Rights and permissions
About this article
Cite this article
Jenns, A.E., Leonard, K.J. & Moll, R.H. Stability analyses for estimating relative durability of quantitative resistance. Theoret. Appl. Genetics 63, 183–192 (1982). https://doi.org/10.1007/BF00303707
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00303707