Four Biotypes of Tylenchulus semipenetrans in California Identified, and Their Importance in the Development of Resistant Citrus Rootstocks

Authors

  • R. C. Baines
  • J. W. Cameron
  • R. K. Soost

Abstract

Four biotypes (pathotypes) of the citrus nematode, Tylenchulus semipenetrans, occurring in California, U.S.A. were differentiated on the basis of differences of infectivity on 'Homosassa' sweet orange, 'Troyer' citrange, 'Pomeroy' and 'Rubidoux' Poncirus trifoliata, 'Thompson Seedless' grape, and 'Manzanillo' olive. A method for differentiating biotypes of T. semipenetrans is described. Field observations indicate that biotypes of this nematode are very stable. The importance of using highly infective biotypes in the development and selection of satisfactory citrus-nematode-resistant rootstocks is emphasized. Key Words: Tylenchulus semipenetrans biotypes.

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Published

1974-04-15

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Section

Articles