Summary
One hundred seven selections from 17 species, 85 selections from controlled interspecific crosses, and a large number of species hybrids of pears were tested for resistance to fire blight (Erwinia amylovora (Burr.) Winsl. et al.). The degree of resistance varied between species and between the clones and selections within species. In species hybrids, resistance varied between selections. Because of this variability, a fixed resistance rating could not be assigned to any given species.
In interspecific crosses, resistance was not consistently transmitted either by crossing a highly resistant with a very susceptible species or by crossing two highly resistant species. The highest degree of overall resistance resulted from crossing two moderately resistant parents. Therefore, a given clone of a species should be tested for its individual degree of resistance before it can be used profitably in a breeding program.
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References
Anderson, H. W., 1928. Seek pear resistant to destructive fire blight. Ill. Agr. Expt. Sta. Ann. Rept. 41: 263–264.
Brooks, H., J. T.van der Zwet & W. A. Oitto, 1967. The pear breeding program of the United States Department of Agriculture. Chron. Hort. 7(2): 34–35.
Cameron, H. R., M. N. Westwood & P. B. Lombard, 1968. Resistance of Pyrus species and cultivars to Erwinia amylovora. Phytopathology 59: 1813–1815.
Carpenter, T. R. & J. R. Shay, 1953. The differentiation of fireblight resistant seedlings within progenies of interspecific crosses of pear. Phytopathology 43: 156–162.
Challice, J. S. & M. N. Westwood, 1972. Phenolic compounds of the genus Pyrus. Phytochemistry 11: 37–44.
Drain, B. D., 1943. Southern pear breeding. Proc. Amer. Soc. hort. Sci. 42: 301–304.
Hansen, N. E., 1915. Breeding pears immune to blight. S. Dak. Agr. Expt. Sta. Ann. Rept. for 1915: 187–191.
Hildebrand, D. C., C. C. PowellJr. & M. N. Schroth, 1969. Fire blight resistance in Pyrus: localization of arbutin and β-glucosidase. Phytopathology 59: 1534–1539.
Hough, L. F., 1944. The new pear breeding project. Ill. State hort. Soc. Trans. 78: 106–113.
Klement, Z. & R. N. Goodman, 1967. The hypersensitive reaction to infection by bacterial plant pathogens. Ann. Rev. Phytopath. 5: 17–44.
Lamb, R. C., 1960. Resistance to fire blight of pear varieties. Proc. Amer. Soc. hort. Sci. 75: 85–88.
Lantz, H. L., 1929. Pear breeding: an inheritance study of Pyrus communis x P. ussuriensis hybrid fruits. Proc. Amer. Soc. hort. Sci. 26: 13–19.
Layne, R. E. C., C. H. Bailey & L. F. Hough, 1968. Efficacy of transmission of fire blight resistance in Pyrus. Can. J. Plant Sci. 48: 231–243.
Magness, J. R., 1937. Progress in pear improvement. U. S. Dept. Agr. Yearbook for 1937: 615–630.
McClintock, J. A., 1929. Fire blight. Tenn. Agr. Expt. Sta. Ann. Rept. 42: 35–36.
Mowry, J. B., 1964. Maximum orchard susceptibility of pear and apple varieties to fireblight. Plant Dis. Reptr. 48: 272–276.
Oitto, W. A., T.van der Zwet & H. J. Brooks, 1970. Rating of pear cultivars for resistance to fire blight. HortScience 5: 474–476.
Patten, C. G., 1917. Origin and development of hardy, blight-resisting pears. Minn. Hort. 45: 97–102.
Reimer, F. C., 1925. Blight resistance in pears and characteristics of pear species and stocks. Ore. Agr. Expt. Sta. Bul. 214, 99 pp.
Shay, J. R., E. B. Williams & J. Janick, 1962. Disease resistance in apple and pear. Proc. Amer. Soc. hort. Sci. 80: 97–104.
Thompson, S. S., J. Janick & E. B. Williams, 1962. Evaluation of resistance to fireblight of pear. Proc. Amer. Soc. hort. Sci. 80: 105–113.
Tukey, H. B. & K. D. Brase, 1943. An attack of fire-blight upon trees of Pyrus betulaefolia. Proc. Amer. Soc. hort. Sci. 43: 129–130.
Westwood, M. N., M. M. Thompson & P. B. Lombard, 1971. Pyrus species and pear cultivar germ plasm collection in Oregon. Fruit Var. hort. Digest 25: 87–89.
Wisker, A. L., 1920. Blight-resistant pear stocks; usuriensis and other species. Grass Valley, Calif., 16 pp.
Zwet, T.van der, 1969. Influence of pear tissue age on infection by Erwinia amylovora. (Abst.) Phytopathology 59: 1561.
Zwet, T.van der, W. A. Oitto & H. J. Brooks, 1970. Scoring system for rating the severity of fire blight in pear. Plant Dis. Reptr. 54: 835–839.
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Van Der Zwet, T., Oitto, W.A. & Westwood, M.N. Variability in degree of fire blight resistance within and between Pyrus species, interspecific hybrids, and seedling progenies. Euphytica 23, 295–304 (1974). https://doi.org/10.1007/BF00035871
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DOI: https://doi.org/10.1007/BF00035871