Sugar beet Stolbur phytoplasma

Rubbery taproot disease (RTD) of sugar beet was observed in Serbia for the first time in the 1960s. The disease was already described in neighboring Bulgaria and Romania at the time but it was associated with abiotic factors. In this study on RTD of sugar beet in its main growing area of Serbia, we provide evidence of the association between ‘Candidatus Phytoplasma solani’ (stolbur phytoplasma) infection and the occurrence of typical RTD symptomatology. ‘Ca. P. solani’ was identified by PCR and the sequence analyses of 16S ribosomal RNA, tuf, secY, and stamp genes. In contrast, the causative agent of the syndrome “basses richesses” of sugar beet—namely, ‘Ca. Arsenophonus phytopathogenicus’—was not detected. Sequence analysis of the stolbur strain’s tuf gene confirmed a previously reported and a new, distinct tuf stolbur genotype (named ‘tuf d’) that is prevalent in sugar beet. The sequence signatures of the tuf gene as well as the one of stamp both correlate with the epidemiological cycle and reservoir plant host. This study provides knowledge that, for the first time, enables the differentiation of stolbur strains associated with RTD of sugar beet from closely related strains, thereby providing necessary information for further epidemiological work seeking to identify insect vectors and reservoir plant hosts. The results of this study indicate that there are differences in hybrid susceptibility. Clarifying the etiology of RTD as a long-known and economically important disease is certainly the first step toward disease management in Serbia and neighboring countries.

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Association with the Syndrome “Basses Richesses” of Sugar Beet of a Phytoplasma and a Bacterium-Like Organism Transmitted by a Pentastiridius sp.

Phytopathology ◽

10.1094/phyto.2002.92.4.384 ◽

2002 ◽

Vol 92 (4) ◽

pp. 384-392 ◽

Cited By ~ 34

Author(s):

F. Gatineau ◽

N. Jacob ◽

S. Vautrin ◽

J. Larrue ◽

J. Lherminier ◽

...

Keyword(s):

Sugar Beet ◽

Pcr Analysis ◽

Gram Negative Bacteria ◽

Positive Signal ◽

Chain Reaction ◽

Dapi Staining ◽

Histochemical Analysis ◽

Transmission Electron ◽

Polymerase Chain ◽

Stolbur Phytoplasma

The syndrome “basses richesses” of sugar beet (SBR) was first observed in 1991 in Burgundy, France. A cixiid planthopper, Pentastiridius beieri, has been proved to be involved in the transmission to sugar beet of a stolbur phytoplasma, which could be detected in some affected plants. In 2000, periwinkle and sugar beet exposed to field-collected cixiids developed symptoms similar to SBR on sugar beet. Use of 4′-6-diamidino-2-phenylindole (DAPI) staining and transmission electron microscopy confirmed the presence of phytoplasma in some of the plants, which were also positive for this pathogen in a polymerase chain reaction (PCR) analysis. A phloem-restricted gram-negative bacteria was seen in all other plants with symptoms but PCR-negative for phytoplasma. Three primer pairs reported as diagnostic for phloem-limited bacteria were tested but only primers specific for ‘Candidatus Phlomobacter fragariae’ gave a positive signal, which related to the presence of DAPI-stained bacteria-like objects in diseased plants. Although phytoplasma and bacterium-like organisms were associated with the same macroscopic symptoms on sugar beet, histochemical analysis of phloem cells showed that phytoplasma were associated with cell necrosis and cell wall lignification, while bacteria were associated with these same abnormalities as well as deposit of phenolic compounds in the lumen of phloem cells.

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Insect Vectors (Hemiptera: Cixiidae) and Pathogens Associated with the Disease Syndrome “Basses Richesses” of Sugar Beet in France

Plant Disease ◽

10.1094/pdis-92-1-0113 ◽

2008 ◽

Vol 92 (1) ◽

pp. 113-119 ◽

Cited By ~ 26

Author(s):

Alberto Bressan ◽

Olivier Sémétey ◽

Benoit Nusillard ◽

Denis Clair ◽

Elisabeth Boudon-Padieu

Keyword(s):

Sugar Beet ◽

High Frequency ◽

Plant Pathogens ◽

Fragment Length Polymorphism ◽

Sugar Content ◽

Urtica Dioica ◽

Convolvulus Arvensis ◽

Primary Vector ◽

Stolbur Phytoplasma

The syndrome “basses richesses” (SBR) is a disease of sugar beet in eastern France associated with two phloem-restricted, nonculturable plant pathogens: a stolbur phytoplasma and a γ-3 proteobacterium, here called SBR bacterium. Three planthopper (Hemiptera: Cixiidae) species were found to live near and within sugar beet fields in eastern France: Cixius wagneri, Hyalesthes obsoletus, and Pentastiridius leporinus. The role of these planthoppers in spreading the two pathogens to sugar beet was studied. Based on its abundance and high frequency of infection with the SBR bacterium, P. leporinus was considered to be the economic vector of SBR disease. C. wagneri, the primary vector of ‘Candidatus Phlomobacter fragariae’ to strawberry in western France, also was found to be infected by the SBR bacterium and to transmit the pathogen to sugar beet. Neither C. wagneri nor P. leporinus were infected by stolbur phytoplasma. Populations of H. obsoletus living on bindweed (Convolvulus arvensis) and nettle (Urtica dioica) collected near sugar beet fields did not carry the SBR bacterium, but were highly infected with two restriction fragment length polymorphism-differentiable stolbur phytoplasma isolates. In transmission assays, only the bindweed phytoplasma isolate was transmissible to and pathogenic on sugar beet. When compared with controls, the bindweed stolbur phytoplasma and SBR bacterium similarly reduced the biomass of sugar beet plants, but the phytoplasma caused greater reductions in taproot biomass and sugar content than the SBR bacterium.

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