Summary
Lesion size and lesion number were measured on cultivars of rice inoculated by clipping or spraying with virulent isolates of Xanthomonas campestris pv. oryzae. Mean percentage diseased leaf area (%DLA) gave a similar ranking for the two inoculation methods but differences in lesion size among cultivars were much more evident after clip than after spray inoculation. Correlation between the methods was high (r=0.82**), but some cultivars responded differently with the two techniques. Cultivars which had low scores following spray inoculation showed low disease progress during the first nine weeks after transplanting into a screen-house experiment. Assessment after clip inoculation measures resistance due to spread of bacteria within the leaf xylem system, an important component of quantitative resistance. Assessment after spray inoculation measures all resistance, including resistance to entrance of bacteria into the leaf. In order to select rice entries with improved quantitative resistance to X. c. oryzae based on both components, a screening based on lesion length after clip inoculation, followed by a test for lesion number after spray inoculation, is advised.
Similar content being viewed by others
References
Fry W.E., 1978. Quantification of general resistance of potato cultivars and fungicide effects for integrated control of potato late blight. Phytopathology 68: 1650–1655.
Kaku H. & T. Kimura, 1978. Reaction types of rice cultivars to strains of Xanthomonas oryzae. Bull. Chugoku Agric. Exp. Stn. Ser. E 13: 17–43.
Kauffman H.E., A.P.K. Reddy, S.P.Y. Hsieh & S.D. Merca, 1973. An improved technique for evaluating resistance of rice varieties to Xanthomonas oryzae. Plant Dis. Reptr. 57: 537–541.
Mew T.W., C.M. Vera Cruz & R.C. Reyes, 1981. Characterization of resistance in rice to bacterial blight. Ann. Phytopathol. Soc. Jpn 47: 58–67.
Morinaka T.H., H. Kaku, M. Hori & T. Kimura, 1978. Applying conditions of the clipping inoculation technique for evaluating resistance of rice to Xanthomonas oryzae. Bull. Chugoku Agric. Exp. Stn, Ser. E 13: 1–16.
Ou S.H., 1985. Rice Diseases, 2nd edition. C.M.I. Kew, England. 380 pp.
Reddy A.P.K., 1989. Crop Loss and Disease Management. pp. 79–88. In: Bacterial blight in rice. International Rice Research Institute. Los Banos, Philippines.
Tsuchiya K., T.W. Mew & S. Wakimoto, 1982. Bacteriological and pathological characteristics of wild types and induced mutants of Xanthomonas campestris pv. oryzae. Phytopathology 72: 43–46.
Yamamoto T., R.H. Hartini, M. Machmud, T. Nishizawa & D.M. Tantera, 1977. Variation in pathogenicity of Xanthomonas oryzae (Uyeda et Ishiyama) Dowson and resistance of rice varieties to the pathogen. Contrib. Cent. Res. Inst. Agric. Bogor 28: 1–22.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Koch, M., Parlevliet, J.E. & Mew, T.W. Assessment of quantitative resistance of rice cultivars to Xanthomonas campestris pv. Oryzae: a comparison of inoculation methods. Euphytica 54, 169–175 (1991). https://doi.org/10.1007/BF00039604
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00039604