Summary
Based on the gene-for-gene relation in race-specific resistance versus virulence, racial complexity of a pathogen population can be revealed by using host lines each with a single gene for resistance as detector. Such inventories of cereal rusts have shown: i. Genes for virulence may have pleiotropic effects acting on general fitness and their relative prevalence. ii. Genes for virulence are, as most other genes, dependent on genetic background for their general fitness. iii. Specific and general gene erosion in a pathogen population submitted to the assortative function of a race-specific host selection pressure is proportional to the degree of existing recombination and thus ultimately upon mode of reproduction (sexual or asexual). iv. Genetic storage capacity is dependent on ploidy constitution. v. Host alternation for safe annual survival favours a genetic system able to store temporarily unnecessary genes for virulence. — Due to shifting circumstances, pathogens like rusts will even inside the same forma specialis show different strategies. The trend may lead to a process of stabilizing selection and dependence on immediate and provisional flexibility just as typical of true haploids. It may lead to a pattern of preparedness: i.e. accumulation of ‘unnecessary’ genes for virulence. In the latter case, the modern concept of gene diversification in breeding for disease resistance is less effective. In the former case, gene accumulation can also work.
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Literature
Bosković, M.; Browder, L.E. (1976): A comparison of pathogenicity of Puccinia recondita tritici in Europe, the United States, and Canada. Plant Dis. Rep. 60, 278–280
Ellingboe, A.M. (1976): Genetics of host-parasite interactions. In: Physiological Plant Pathology (eds.: R. Heitefuss; R.H. Williams). Encycl. Plant Physiol. N.S. 4, 761–778
Fisher, R.A. (1931): The evolution of dominance. Biol. Rev. Cambridge, 6, 345–368
Flor, H.H. (1942): Inheritance of pathogenicity in Melampsora lini. Phytopathology 32, 653–669
Freitas, A.P.C. (1959): (Puccinia recondita Rob. I. Survey of physiologic races on wheat in 1956 and 1957). Agron. Lusitana 21, 239–268
Freitas, A.P.C. (1961): (Puccinia recondita Rob. II. Survey of biotypes during the year 1958 and reaction of some wheats in the seedling stage). Agron. Lusitana 23, 85–102
Freitas, A.P.C. (1966): (Puccinia recondita Rob. III. Survey of physiologic races in Portugal during 1959, 1960 and 1961 and the reaction of some wheats in the seedling stage). Agron. Lusitana 26, 91–114
Frey, K.J.; Browning, J.A.; Simons, M.D. (1977): Management systems for host genes to control disease loss. Ann. New York Acad. Sci. 287, 255–274
Green, G.J.; McKenzie, R.I.H. (1967): Mendelian and extrachromosomal inheritance of virulence in Puccinia graminis f.sp. avenae. Can. J. Genet. Cytol. 9, 785–793
Groth, J.V.; Person, C.O. (1977): Genetic interdependence of host and parasite in epidemics. Ann. New York Acad. Sci. 287, 97–106
Harlan, J.R. (1976): Diseases as a factor in plant evolution. Ann. Rev. Phytopathol. 14, 31–51
Johnston, C.O. (1957): Physiologic races of Puccinia rubigo-vera f.sp. tritici in the United States in 1956. Plant Dis. Rep. 41, 853–855
Johnston, C.O. (1958): Physiologic races of Puccinia recondita (P. rubigo-vera f.sp. tritici) in the United States in 1957. Plant Dis. Rep. 42, 1244–1445
Johnston, C.O. (1959): Physiologic races of the leaf rust of wheat, Puccinina recondita Rob. ex Desm., in the United States in 1958. Plant Dis. Rep. 43, 998–999
Johnston, C.O. (1960): Physiologic races of leaf rust of wheat, Puccinia recondita Rob. ex Desm. f.sp. tritici, in the United States in 1959. Plant Dis. Rep. 44, 778–779
Jörgensen, J. Helms (1976): Studies on recombination between alleles in the ml-o locus of barley and pleiotropic effects of the alleles. Proc. Res. Co-ord. Meet. on ‘Induced Mutations for Disease Resistance in Crop Plants’, Ames 1975, IAEA, Vienna Sti/Pub/181, 129–140
Leijerstam, B. (1962): Studies in powdery mildew on wheat in Sweden. I: Physiological races in Scandinavia in 1960 and 1961. Nat. Inst. Plant Protect. Contr. 12(94), 283–293
Leijerstam, B. (1965): Studies in powdery mildew on wheat in Sweden. II. Physiological races in Scandinavia in 1962 and 1963 and the resistance in a number of wheats to Scandinavian races. Nat. Inst. Plant Protect. Contr. 13(103), 153–183
Leonard, K.J. (1969): Genetic equilibria in host-pathogen systems. Phytopathology 59, 1858–1863
Leonard, K.J. (1977): Selection pressures and plant pathogens. Ann. New York Acad. Sci. 287, 207–222
Lesovoj, M.P.; Shkodenko, W.I.; Panteleev, W.K. (1976): The loss of resistance to leaf rust in the wheat varieties ‘Avrora’ and ‘Kavkas’. Proc. 4th Europ. Mediterr. Cereal Rusts Conf. Interlaken 1976, pp. 32–34. Zürich: Swiss Fed. Res. Sta. Agron.
Luig, N.H. (1979): Mutation studies in Puccinia graminis tritici. Proc. 5th Int. Wheat Genet. Symp., New Delhi 1978. Indian Soc. Genet. Plant Breed., New Delhi, 1, 533–539
Luig, N.H.; Baker, E.P. (1973): Variability in oat stem rust in Eastern Australia. Proc. Linn. Soc. N.S.W. 98, 53–61
Mac Key, J. (1974): Systematic approach to race-specific disease resistance. Proc. Res. Co-ord. Meet. on ‘Induced Mutations for Disease Resistance in Crop Plants’, Novi Sad 1973, IAEA, Vienna Sti/Pub/388, 9–22
Mac Key, J. (1977): Strategies of race-specific phytoparasitism and its control by plant breeding. Genetica, Acta Biol. Jugoslav. 9, 237–255
Mac Key, J.; Leijerstam, B.; Wiberg, A. (1963): Resistance to rust and mildew in cereals. In ‘Recent plant breeding research, Svalöf 1946–1961’ (eds.: E. Akerberg et al.) pp. 203–221 Stockholm: Almqvist & Wiksell
Mac Key, J.; Mattsson, B. (1972): Breeding for race-specific resistance against Scandinavian oat stem rust. Sveriges Utsädesf. Tidskr. 82, 186–203
Marshall, D.R.; Pryor, A.J. (1978): Multiline varieties and disease control. I. The ‘dirty crop’ approach with each component carrying a unique single resistance gene. Theor. Appl. Genet. 51, 177–184
Martens, J.W.; McKenzie, R.I.H.; Green, G.J. (1970): Gene-for-gene relationships in the Avenu:Puccinia graminis host-parasite system in Canada. Can. J. Bot. 48, 969–975
Mode, C.J. (1958): A mathematical model for the co-evolution of obligate parasites and their hosts. Evolution 12, 158–165
Parlevliet, J.E.; Zadoks, J.C. (1977): The integraded concept of disease resistance: a new view including horizontal and vertical resistance in plants. Euphytica 26, 5–21
Person, C. (1959): Gene-for-gene relationships in host: parasite systems. Can. J. Bot. 37, 1101–1130
Person, C. (1966): Genetic polymorphism in parasitic systems. Nature 212, 266–267
Ralski, E. (1972): Physiological differentiation of cereal rusts in Poland and resistant varieties. Proc. 3rd Europ. Mediterr. Cereal Rusts Conf., Praha 1972, 225–227
Stewart, D.M.; Radulescu, E.; Negulescu, Fl. (1967): Physiologic races of Puccinia recondita and P. graminis in Rumania in 1964 and 1965. Plant Dis. Rep. 51, 358–366
Stewart, D.M.; Roberts, B.J. (1970): Identifying races of Puccinia graminis f.sp. avenue. A modified international system. USDA Dept. Agric. and Minnesota Agric. Exp. Sta. Techn. Bull. No. 1416
Van der Plank, J.E. (1968): Disease resistance in plants. New York: Acad. Press
Wahl, I.; Dinoor, A.; Gerechter-Amitai, Z.K.; Sztenjnberg, A. (1964): Physiological specialization, host range and development of oat stem rust in Israel. Proc. 1st Cereal Rusts Conf., Cambridge 1964, Plant Breed. Inst., Cambridge, 242–253
Watson, I.A. (1977): The national wheat rust control programme in Australia. Plant Breed. Inst., Fac. Agric., Univ. Sydney, Sydney
Watson, I.A.; Luig, N.H. (1968): Progressive increase in virulence in Puccinia aranfinis f.sp. tritici. Phytopathology 56, 70–73
Wolfe, M.S. (1972): The genetics of barley mildew. Rev. Plant Pathol. 51, 507–522
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Communicated by H.F. Linskens
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Mac Key, J. Alternative strategies in fungal race-specific parasitism. Theoret. Appl. Genetics 59, 381–390 (1981). https://doi.org/10.1007/BF00276454
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DOI: https://doi.org/10.1007/BF00276454