Resistance to Anthracnose in Cucurbits – An Overview

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Cucurbit Genetics Cooperative Report 6:66-67 (article 33) 1983

B. B. Rhodes and S. Love
Clemson University, Edisto Experiment Station, Blackville, SC 29817

The genetics of anthracnose resistance and the physiology of anthracnose resistance are approaching the integration stage in cucurbits.

Barnes and Epps (1) reported that two types of resistance to anthracnose exist in cucumber. Several genes control immunity, and a single dominant gene imparts a high level of resistance. Busch and Walker (2) verified this report and noted that cell walls thicken in the resistant tissue infected by the fungus.

Robinson et al (9) noted that several reports indicated that a single dominant gene controlled resistance to anthracnose in watermelon. Suvanprakorn and Norton (12) reported that resistance to race 2 in the three PI’s was controlled by a single dominant gene. We find that resistance to race 2 can be governed by several genes. However, we reported previously in this newsletter (11) that a hypersensitive response to race 2 may be controlled by a single dominant gene that lacks 100% penetrance.

Since the report by Busch and Walker (2) that cell wall changes occur in the host, the relationship of anthracnose to its host has been studied in several cucurbits. Caruso and Kuc (3) showed that systemic protection against anthracnose in watermelons and muskmelons could be induced by a small dose of the pathogen. Hammerschmidt and Kuc (6, 7, 8) later reported changes in isoperoxidases and enhanced lignification in response to a challenge dose of the pathogen in protected cukes. Love and Rhodes (9) noted significant differences in the isoperoxidase profiles of resistant and susceptible watermelon genotypes in response to infection. Touze and Rossignol (13) reported an increase in lignin, notedly guaiacol and p-coumaryl lignin in watermelon, in response to a challenge dose of the pathogen. Esquerre-Tugaye and Mazau (5) reported that the cell wall protein, extensin is modified by C. lagenarium in Cucumis melo.

The isoperoxidase system in Cucurbita pepo is similar to that in Cucumis and Citrullus (4), but the effect of anthracnose on this system has not been studied.

We have the genetic material to investigate how the fungus induces changes in the isoperoxidase system which may in turn control lignification. Vance (14) suggested that information on the inheritance of induced lignification is essential to full understanding of the role of lignification in resistance.

Literature Cited

  1. Barnes, W. C. and W. M. Epps. 1952. Two types of anthracnose resistance in cucumbers. Plant Dis. Rptr. 36:479–480.
  2. Busch, L. V. and J. C. Walker. 1958. Studies of cucumber anthracnose. Phytopath. 48(6):302–304.
  3. Caruso, F. L. and J. Kuc. 1977. Protection of watermelon and muskmelon against Colletotrichum lagenarium by Colletotrichum lagenarium. Phytopath. 67:1285–1289.
  4. Denna, D. W. and M. B. Alexander. 1975. The isoperoxidases of Cucurbita pepo L. In: Isoenzymes II: Physiological Function. Academic Press, Inc. pp. 851–864.
  5. Esqueere-Tugaye, M. G. and D. Mazau.1974. Effect of fungal disease on extension, the plant cell wall glycoprotein. J. Exp. Bot. 25(86):509–513.
  6. Hammerschmidt, R. and J. Kuc. 1980. Enhanced peroxidase activity and lignification in the induced systemic protection of cucumber. Phytopath. 70:689.
  7. Hammerschmidt, R., E. M. Nuckles and J. Kuc. 1982. Association of enhanced peroxidase activity with induced systemic resistance of cucumber to Colletotrichum lagenarium. Physiol. Pl. Path. 16:1–9.
  8. Hammerschmidt, R. and J. Kuc. 1982. Lignification as a mechanism for induced systemic resistance in cucumber. Physiol. Pl. Path. 20:61–71.
  9. Love, S. and B. B. Rhodes. 1982. The effect of race 2 anthracnose on peroxidases and lignin in resistant watermelon plants. HortSci. 17(3):502.
  10. Robinson, R. W., H. M. Munger, T. W. Whitaker, and G. W. Bohn. 1976. Genes of the Cucurbitaceae. HortSci. 11(6):564–568.
  11. Rhodes, B. B. 1981. Hypersensitivity to anthracnose infection in Citrullus lanatus. Cucurbit Genetics Coop. 4:29.
  12. Suvaprakorn, K. and J. D. Norton. 1980. Inheritance of resistance to race 2 anthracnose in watermelon. J. Amer. Soc. Hort. Sci. 105(6):862–865.
  13. Touze, A. and M. Rossignol. 1977. Lignification and the onset of premunition in muskmelon plants. In: Cell Wall Biochemistry Related to Specificity in Host-Plant Pathogen Interactions. ed. B. Soheim, J. Raa. Tromson Universitetsforlaget. pp. 289–292.
  14. Vance, C. P., T. K. Kirk and R. T. Sherwood. 1980. Lignification as a mechanism of disease resistance. Ann. Rev. Phytopath. 18:259–288.