European Journal of Plant Pathology

, Volume 117, Issue 3, pp 281–291 | Cite as

Detection and identification of the phytoplasma associated with pear decline in Taiwan

  • Hsiu-Lin Liu
  • Ching-Chung Chen
  • Chan-Pin Lin
Full Research Paper


Pear decline (PD) is an important phytoplasmal disease that occurs mainly in Europe and North America. In 1994, pear trees exhibiting symptoms typical of PD disease were observed in orchards of central Taiwan. The sequence of 16S rDNA and 16S–23S rDNA intergenic spacer region (ISR) of the causative agent of pear decline in Taiwan (PDTW) were amplified with polymerase chain reaction (PCR) using a DNA template prepared from the diseased leaves. Sequence analysis of 16S rDNA revealed that the PDTW agent was closely related to the phytoplasmas of the apple proliferation group that cause diseases in stone fruits, pear and apple. Consistent with the result of 16S rDNA sequence analysis, sequence analysis of the 16S–23S rDNA ISR and putative restriction site analyses of 16S rDNA and 16S–23S rDNA ISR sequences provided further support for the view that the PDTW phytoplasma causing pear decline in Taiwan may represent a new subgroup of the apple proliferation group. According to the rDNA sequence of PDTW phytoplasma, two specific PCR primer pairs, APf2/L1n and fPD1/rPDS1, were designed in this study for the detection of the etiological agent in pear trees and insect vectors. Based on the sequence analyses of the PCR-amplified fragments, two species of pear psyllas, Cacopsylla qianli and Cacopsylla chinensis, were found to carry PDTW phytoplasma.


Phytoplasma vectors rRNA 



The authors would like to thank Dr M. M. Yang (Department of Entomology, National Chung Hsing University) for the supply of field-collected pear psyllas, and Dr T. L. Shen and Dr W. C. Shen (Department of Plant Pathology and Microbiology, National Taiwan University) for comments on an earlier version of the manuscript.


  1. Agrios, G. N. (2005). Plant pathology, 5th edn. San Diego, California: Academic Press.Google Scholar
  2. Avinent, L., Llácer, G., Almacellas, J., & Torá, R. (1997). Pear decline in Spain. Plant Pathology, 46, 694–698.CrossRefGoogle Scholar
  3. Blomquist, C. L., & Kirkpatrick, B. C. (2002). Identification of phytoplasma taxa and insect vectors of peach yellow leaf roll disease in California. Plant Disease, 86, 759–763.Google Scholar
  4. Chen, C. C., Liu, T. D., Lin, C. P., & Kuo, K. C. (2001). Comments on the disease similar to pear decline in Taiwan. Plant Pathology Bulletin, 43, 1–5.Google Scholar
  5. Chou, L., & Fang, S. (1994). New record of Psylla qianli (Homoptera: Psyllidae) from Taiwan. Journal of Agricultural Research of China, 43, 467–468.Google Scholar
  6. Davies, D. L., Barbara, D. J., & Clark, M. F. (1995). The detection of MLOs associated with pear decline in pear trees and pear psyllids by polymerase chain reaction. Acta Horticulturae, 386, 484–488.Google Scholar
  7. Davies, D. L., Guise, C. M., Clark, M. F., & Adams, A. N. (1992). Parry’s disease of pears is similar to pear decline and is associated with mycoplasma-like organisms transmitted by Cacopsylla pyricola. Plant Pathology, 41, 195–203.Google Scholar
  8. Deng, S., & Hiruki, D. (1991). Amplification of 16S rRNA genes from culturable and nonculturable mollicutes. Journal of Microbiological Methods, 14, 53–61.CrossRefGoogle Scholar
  9. Garcia-Chapa, M., Laviňa, A., Sanchez, I., Medina, V., & Batlle, A. (2003). Occurrence, symptom expression and characterization of phytoplasma associated with pear decline disease in Catalonia (Spain). Journal of Phytopathology, 151, 584–590.CrossRefGoogle Scholar
  10. Hibino, H., Kaloostian, G. H., & Schneider, H. (1971). Mycoplasma-like bodies in the pear psylla vector of pear decline. Virology, 43, 34–40.PubMedCrossRefGoogle Scholar
  11. Jung, H.-Y., Sawayanagi, T., Kakizawa, S., Nishigawa, H., Wei, W., Oshima, K., Miyata, S.-i., Ugaki, M., Hibi, T., & Namba, S. (2003). ‘Candidatus Phytoplasma ziziphi’, a novel phytoplasma taxon associated with jujube witches’-broom disease. International Journal of Systematic and Evolutionary Microbiology, 53, 1037–1041.PubMedCrossRefGoogle Scholar
  12. Lee, I. M., Davis, R. E., & Gundersen-Rindal, D. E. (2000). Phytoplasma: Phytopathogenic Mollicutes. Annual Review of Microbiology, 54, 221–255.PubMedCrossRefGoogle Scholar
  13. Lin, T. C., & Lin, C. P. (1998). Evaluation of universal PCR primers for the detection of phytoplasmas. Plant Pathology Bulletin, 7, 33–42.Google Scholar
  14. Lorenz, K. H., Schneider, B., Ahrens, U., & Seemüller, E. (1995). Detection of the apple proliferation and pear decline phytoplasmas by PCR amplification of ribosomal and nonribosomal DNA. Phytopathology, 85, 771–776.Google Scholar
  15. Marcone, C., Lee, I.-M., Davis, R. E., Ragozzino, A., & Seemüller, E. (2000). Classification of aster yellows-group phytoplasmas based on combined analyses of rRNA and tuf gene sequences. International Journal of Systematic and Evolutionary Microbiology, 50, 1703–1713.PubMedGoogle Scholar
  16. Marcone, C., Schneider, B., & Seemüller, E. (2004). ‘Candidatus Phytoplasma cynodontis’, the phytoplasma associated with Bermuda grass white leaf disease. International Journal of Systematic and Evolutionary Microbiology, 54, 1077–1082.PubMedCrossRefGoogle Scholar
  17. Martín, R., Carazo, G., Arribas, C., Colino, I., Santiago, R., & De Blas, C. (2001). Four Spanish isolates of pear decline phytoplasma are related to other European phytoplasmas of the apple proliferation group. Journal of Phytopathology, 149, 481–484.CrossRefGoogle Scholar
  18. Nicholas K. B., & Nicholas H. B. Jr. (1997). GeneDoc: A tool for editing and annotating multiple sequence alignments. Distributed by the author [].
  19. Regassa, L. B., Stewart, K. M., Murphy, A. C., French, F. E., Lin, T., & Whitcomb, R. F. (2004). Differentiation of group VIII Spiroplasma strains with sequences of the 16S–23S rDNA intergenic spacer region. Canadian Journal of Microbiology, 50, 1061–1067.PubMedCrossRefGoogle Scholar
  20. Salehi, M., Izadpanah, K., & Heydarnejad, J. (2006). Characterization of a new almond witches’_broom phytoplasma in Iran. Journal of Phytopathology, 154, 386–391.CrossRefGoogle Scholar
  21. Schaper, U., & Seemüller, E. (1982). Condition of the phloem and the persistence of mycoplasma-like organisms associated with apple proliferation and pear decline. Phytopathology, 72, 736–742.Google Scholar
  22. Schneider, B., & Gibb, K. S. (1997). Detection of phytoplasmas in declining pears in southern Australia. Plant Disease, 81, 254–258.Google Scholar
  23. Schneider, B., Seemüller, E., Smart, C. D., & Kirkpatrick, B. C. (1995). Phylogenetic classification of plant pathogenic mycoplasma-like organisms or phytoplasmas. In: S. Razin & J. G. Tully (Eds.), Molecular and diagnostic procedures in mycoplasmology (Vol 1, pp. 369–380). San Diego, California: Academic Press.Google Scholar
  24. Schneider, H. (1977). Indicator hosts for pear decline: symptomatology, histopathology, and distribution of mycoplasma-like organisms in leaf veins. Phytopathology, 67, 592–601.CrossRefGoogle Scholar
  25. Seemüller, E. (1990). Pear decline. In: A. L. Jones, & H. S. Aldwinckle (Eds.), Compendium of apple and pear disease (pp. 68–69). St. Paul, Minnesota: APS Press.Google Scholar
  26. Seemüller, E. (1992). Pear decline. In: J. Kumar, H. S. Chaube, U. S. Singh, & A. N. Mukhopadhyay (Eds.), Plant diseases of international importance (Vol 3, pp. 308–334). Eaglewood Cliffs, New Jersey: Prentice Hall.Google Scholar
  27. Seemüller, E., Marcone, C., Lauer, U., Ragozzino, A., & Göschl, M. (1998). Current status of molecular classification of the phytoplasmas. Journal of Plant Pathology, 80, 3–26.Google Scholar
  28. Seemüller, E., & Schneider, B. (2004). ‘Candidatus Phytoplasma mali’, ‘Candidatus Phytoplasma pyri’ and ‘Candidatus Phytoplasma prunorum’, the causal agents of apple proliferation, pear decline and European stone fruit yellows, respectively. International Journal of Systematic and Evolutionary Microbiology, 54, 1217–1226.PubMedCrossRefGoogle Scholar
  29. The IRPCM Phytoplasma/Spiroplasma Working Team - Phytoplasma taxonomy group (2004). ‘Candidatus Phytoplasma’, a taxon for the wall-less, non-helical prokaryotes that colonize plant phloem and insects. International Journal of Systematic and Evolutionary Microbiology, 54, 1243–1255.CrossRefGoogle Scholar
  30. Thompson, J. D., Plewniak, F., & Poch, O. (1999). A comprehensive comparison of multiple sequence alignment programs. Nucleic Acids Research, 27, 2682–2690.PubMedCrossRefGoogle Scholar
  31. Yang, M.-M., Huang, J.-H., & Li, F. (2004). A new record of Cacopsylla species (Hemiptera: Psyllidae) from pear orchards in Taiwan. Formosan Entomology, 24, 213–220.Google Scholar

Copyright information

© KNPV 2007

Authors and Affiliations

  1. 1.Department of Plant Pathology and MicrobiologyNational Taiwan UniversityTaipeiTaiwan, ROC
  2. 2.Department of Plant ProtectionTaichung District Agricultural Improvement StationChanghuaTaiwan, ROC

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