First identification of the pathogen causing tumor malformations in evergreen oaks in Spain

María Martín-Santafé, Sergio Sánchez-Durán, Assumpció Batlle-Durany, Amparo Laviña-Gomila, Juan Barriuso-Vargas


Aim of study: In recent years an increase in pests and diseases associated with truffle plantations has been detected in Spain. The appearance of tumor malformations in trunks and branches of Quercus ilex L. must be highlighted. These bumps have expanded dramatically since the increase in the number and density of truffle plantations. This pathology is not only found in plantations, but also in forests, and in trees of all ages.

Area of study: the eastern mountains and the truffle plantations of the Iberian Peninsula.

Material and methods: Positive results were obtained by using two types of PCR: Real-Time PCR and nested-PCR. They were carried out with primers that amplified 16S ribosomal gene sequences that are common to all known phytoplasmas.

Main result: The disease manifests itself as an irregular thickening in branches of any age and in the trunk that results in the woody tissue cracking open, forming wounds. The affected branches usually undergo necrosis and in case of affecting the trunk, the tree will eventually die. After an extensive literature review and several failed attempts to isolate fungal and bacterial species from these tumors and wounds, the disease-causing organism has been identified as a Candidatus Phytoplasma.

Research highlights: The appearance of this disease may endanger the profitability of an a priori profitable crop. Due to the intrinsic characteristics of the organism, and knowing that no phytosanitary treatment is able to control phytoplasmas, future works should be directed towards identifying the transmitter in order to control the disease.

Key words: Candidatus Phytoplasma; PCR; Quercus ilex; black truffle; Tuber melanosporum.

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Ahrens U, Seemüller E, 1992. Detection of DNA of plant pathogenic mycoplasmalike organisms by a polymerase chain reaction that amplifies a sequence of the 16 S rRNA Gene. Phytopathology 82: 828-832.

Agrios GN, 2011. Fitopatología. Ed Limusa. México. 838 pp.

Arismendi N, Carrillo R, Andrade S, 2010. Phytopathogen mollicutes transmitted by insects: interactions and effects on their vectors. Agro Sur 38(2): 55-67.

Barriuso J, Martín M, Sánchez S, Palazón C, 2012. Plagas y enfermedades asociadas al cultivo de la trufa. In: Reyna S (ed). Truficultura. Fundamentos y Técnicas (2). Ed Mundi-Prensa, Madrid. pp: 275-301.

Batlle A, Altabella N, Sabaté J, Lavi-a A, 2008. Study of the transmission of Stolbur Phytoplasma to different crop species, by Macrosteles quadripunctulatus (Kirschbaum). Ann Appl Biol 152: 235-242.

Berges R, Rott M, Seemüller E, 2000. Range of Phytoplasma Concentrations in Various Plant hosts as determined by competitive polymerase chain reaction. Am Phytopathol Soc 90(10): 1154-1152.

Bertaccini A, Duduk B, 2009. Phytoplasma diseases; a review of recent research. Phytopatol Medit 48: 355-378.

Carraro L, Loi N, Ermacora P, Gregoris A, Osler R, 1998. Transmission of pear decline by using naturally infected Cacopsylla pyri. Acta Horticulturae 472: 665-668.

Christensen NM, Nicolaisen M, Hansen M, Schulz A, 2004. Distribution of phytoplasmas in infected plants as revealed by real-time PCR and bioimaging. Mol Plant Microbe In 17: 1175-1184.

Deng S, Hiruki C, 1991. Amplification of 16S rRNA genes from culturable and nonculturable mollicutes. J. Microbiol. Meth 14: 53-61.

García-Chapa M, Laviña A, Sánchez I, Medina V, Batlle A, 2003. Occurrence, Symptom Expression and Characterization of Phytoplasma Associated with Pear Decline in Catalonia (Spain). J Phytopathol 151: 584-590.

García-Chapa M, Sabaté J, Laviña A, Batlle A, 2005. Role of Cacopsylla pyri in the epidemiology of pear decline in Spain. Eur J Plant Pathol 111: 9-17.

Gundersen DE, Lee IM, 1996. Ultrasensitive detection of phytoplasmas by nested-PCR assays using two universal primer pairs. Phytopathol Mediterr 35: 144-151.

Hiruki C, 1999. Paulownia witches'-broom disease important in East Asia. Acta Horticulturae 496: 63-68.

Lavi-a A, Sabaté J, García-Chapa M, Batlle A, Torres E, 2004. Occurrence and epidemiology of European stone fruit yellows phytoplasma in Spain. Acta Horticulturae 657: 489-494.

Laviña A, Sabaté J, Batlle A, 2011. "Candidatus Phytoplasmas mali": identification of potencial insecto vectors in Spanish apple ochards. Second International Phytoplasmologist Working Group Meeting. Neustadt an der Weinstrasse, Germany. September 12-15.

Lee IM, Gavis RE, Dawn E, 2000. Phytoplasma: phytopathogenic Mollicutes. Annu Rev Microbiol 54: 221-255.

Marcone C, Ragozzino A, Cousin MT, Berges R, Seemüler E, 1999. Phytoplasma diseases of trees and shrubs of urban areas in Europe. In: Acta Horticulturae (496) Leuven: International Society for Hortucultural Science (ISHS) pp: 69-75.

Mathen K, Rajan P, Radhakrishnan CP, Sasikala M, Gunasekharan M, Govindankutty MP, Solomon JJ, 1990. Transmission of root (wilt) disease to coconut seedlings through Stephanitis typica (Distant) (Heteroptera: Tingidae). Trop Agric 67: 69-73.

Nielson MW, 1979. Taxonomic relationships of leafhopper vectors of plant pathogens. In: Maramorosch K, Harris KF (eds). Leaf- hopper Vectors and Plant Disease Agents. New York: Academic Press pp: 3-27.

Quintana A, 2007. Establecimiento y rentabilidad de una plantación trufera. Sustrai: revista agropesquera 81: 56-58.

Reyna S, Folch L, Alloza JA, 2002. La truficultura: una dehesa rentable para los encinares en suelos calizos. Cuadernos de la Sociedad Española de Ciencias Forestales 14: 95-102.

Samils N, Olivera A, Danell E, Alexander SJ, Colinas C, 2003. Aportación de la truficultura al desarrollo socioeconómico. Vida rural 181: 54-60.

Samils N, Olivera A, Danell E, Alexander SJ, Fischer C, Colinas C, 2008. The Socioeconomic Impact of Truffle Cultivation in Rural Spain. Economic Botany 62(3): 331-340.

Schneider B, Marcone C, Kampmann M, Ragozzino A, Lederer W, Cousin MT, Seemüller E, 1997. Characterization and classification of phytoplasmas from wild and cultivated plants by RFLP and sequence analysis of ribosomal DNA. Eur J Plant Pathol 103: 675-686.

Seemüler E, Schneider B, 2004. "Candidatus Phytoplasma mali", "Candidatus Phytoplasma piri", and "Candidatus Phytoplasma prunorum", the causal agents of apple proliferation, pear decline and European stone fruit yellows, respectively. Int J Syst Evol Micr 54: 1217-1226.

Smart CD, Schneider B, Blomquist CL, Guerra LJ, Harrison NA, Ahrens U, Lorenz KH, Seemüller E, Kirkpatrick B, 1996. Phytoplasma-Specific PCR Primers Based on Sequences of the 16S-23S rRNA Spacer Region. Appl Environ Microb 62: 2988-2993.

Tedeschi R, Visentin C, Alma A, Bosco D, 2003. Epidemiology of apple proliferation (AP) in north western Italy. Evaluation of the frequency of AP-positive in naturally infected populations of Cacopsylla melanoneura. Ann Appl Biol 142: 285-290.

DOI: 10.5424/fs/2014232-04927