New Disease Reports
New Disease Reports (2012) 25, 4. [http://dx.doi.org/10.5197/j.2044-0588.2012.025.004]
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First report of 'Candidatus Phytoplasma asteris' (16SrI group) affecting common bean in Cuba

L. Zamora 1*, K. Acosta 2 and Y. Martínez 1

*loidy@censa.edu.cu

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Received: 14 Oct 2011; Published: 10 Feb 2012

Keywords: Phaseolus vulgaris, 16SrI phytoplasma

Common bean (Phaseolus vulgaris) is an important herbaceous plant in the Fabaceae, grown worldwide as a human food crop and fodder. Recently, symptoms of yellowing, short internodes, stunting, shoot proliferation and chlorosis of crown leaves have been observed in approximately 10% of plants in two common bean fields in the locality of San José of Havana province (Fig. 1), surveyed during 2009-2010. Similar symptoms were previously associated with a phytoplasma infection in Vicia faba in Havana province (Arocha et al., 2007); therefore a possible phytoplasma infection was investigated.

Total extracted DNA was used as a template in a nested PCR assay with universal primers that target the phytoplasma 16S ribosomal RNA gene (16S rRNA): R16mF2/R1 (Gundersen & Lee, 1996) for the first PCR amplification followed by fU5/rU3 (Lorenz et al., 1995) for the nested reaction. PCR amplicons (~880 bp) were obtained for 10 out of 22 symptom-bearing plants, but not from the symptomless plants. Restriction profiles after digestion of PCR amplicons with HpaII, HaeIIIand Sau3AI endonucleases were all identical to each other and to those of phytoplasma references of 'Candidatus Phytoplasma asteris' (16SrI group). Five representative amplicons were purified(Wizard SV Gel and PCR Clean-Up System, Promega, Madison, WI, USA), cloned (pGEMT-Easy Vector, Promega, USA), and sequenced bi-directionally.

The partial 16S rDNA sequences shared 100% identity with each other, and the consensus sequence was deposited in GenBank (Accession No. JN383914). The 16S rDNA consensus sequence exhibited the highest sequence identity of 99% with those of phytoplasmas of the 'Ca. Phytoplasma asteris' (16SrI group) (Fig. 2). This group has been previously recorded in broad bean and sweet pepper (Arocha et al., 2007) and other vegetable crops in western Cuba (Arocha et al., 2009), and it has been also associated with 'amachamiento' disease of dry common bean in Costa Rica (Moreira et al., 2010).Since 16SrI is the phytoplasma group with the widest host range and since a number of species of the Fabaceae have been found infected by this group in Cuba, particularly in Havana province, our results significantly impact the development of further management strategies for the common bean crop in western Cuba.

Figure1+
Figure 1: Figure 1: Common bean plants observed in common bean fields in western Cuba: with symptoms of short internodes, stunting, and chlorosis of crown leaves (A), shoot proliferation (B), yellowing (C) and symptomless (D).
Figure 1: Figure 1: Common bean plants observed in common bean fields in western Cuba: with symptoms of short internodes, stunting, and chlorosis of crown leaves (A), shoot proliferation (B), yellowing (C) and symptomless (D).
Figure2+
Figure 2: Figure 2. Phylogenetic relationships between the common bean phytoplasma 16SrI from Cuba (JN383914) and GenBank reference phytoplasmas of group 16SrI and other groups affecting Fabaceae species. Ca. P.: ‘Candidatus Phytoplasma sp.’ CU: Cuba, CR: Costa Rica, SP: Spain, PAK: Pakistan, UK: United Kingdom, JP: Japan, IT: Italy, USA: United States of America. 16SrII corresponds to ‘Candidatus Phytoplasma aurantifolia’, former Faba bean phyllody group.
Figure 2: Figure 2. Phylogenetic relationships between the common bean phytoplasma 16SrI from Cuba (JN383914) and GenBank reference phytoplasmas of group 16SrI and other groups affecting Fabaceae species. Ca. P.: ‘Candidatus Phytoplasma sp.’ CU: Cuba, CR: Costa Rica, SP: Spain, PAK: Pakistan, UK: United Kingdom, JP: Japan, IT: Italy, USA: United States of America. 16SrII corresponds to ‘Candidatus Phytoplasma aurantifolia’, former Faba bean phyllody group.

Acknowledgements

We thank Berta Pinol for excellent technical help.

References

  1. Arocha Y, Piñol B, Almeida R, Acosta K, Quiñones M, Zayas T, Varela M, Marrero Y, Boa E, Lucas JA, 2009. First report of phytoplasmas affecting organoponic crops in central and eastern Cuba. Plant Pathology 58, 793. [http://dx.doi.org/10.1111/j.1365-3059.2009.02027.x]
  2. Arocha Y, Piñol B, Picornell B, Almeida R, Jones P, 2007. Broad bean and sweet pepper: two new hosts associated with Candidatus Phytoplasma asteris (16SrI phytoplasma group) in Cuba. Plant Pathology 56, 345. [http://dx.doi.org/10.1111/j.1365-3059.2007.01518.x ]
  3. Gundersen DE, Lee IM, 1996. Ultrasensitive detection of phytoplasmas by nested-PCR assays using two universal primer sets. Phytopathologia Mediterranea 35, 144-151.
  4. 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. [http://dx.doi.org/10.1094/Phyto-85-771]
  5. MoreiraL, Villalobos W, Saborío-R G, Garita L, Castro-Robleda S, Romero-Cano J, Ramírez P, Rivera C, 2010. A phytoplasma associated with 'amachamiento' disease of dry common bean in Costa Rica. Plant Pathology 59, 398. [http://dx.doi.org/10.1111/j.1365-3059.2009.02128.x ]
To cite this report: Zamora L, Acosta K, Martínez Y, 2012. First report of 'Candidatus Phytoplasma asteris' (16SrI group) affecting common bean in Cuba. New Disease Reports 25, 4. [http://dx.doi.org/10.5197/j.2044-0588.2012.025.004]

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