Surveys on phytoplasmas associated with potatoes in Romania and Southern Russia
Surveys were carried out in 2008/2009 to identify phytoplasmas associated with potato crops in Romania and Southern Russia using molecular techniques. Symptomatic potato plants (Solanum tuberosum) were collected from several fields in both countries and tested by PCR for the presence of phytoplasmas. Samples of weeds (e.g. Convolvulus arvensis) and adjacent crops (including Beta vulgaris, Capsicum annuum, Solanum lycopersicum, S. melongena, Zea mays) were also included. In both countries, stolbur was the only phytoplasma detected in potatoes. It is noted that a large number of potato tubers (27%) collected from phytoplasma-infected fields had a spongy appearance which resulted in commercially unacceptable potato chips upon processing. Genotyping (tuf genes) of obtained stolbur isolates revealed that they all had the same RFLP profile corresponding to the ‘tuf-type b’, a genotype known to be associated with the weed C.;arvensis. These results suggest that this weed probably constitutes a major source of inoculum for potato crops in Romania and Southern Russia. According to the authors, the results of these surveys (more detail is presented below) indicate that stolbur is a major pathogen associated with phytoplasma diseases of potato in Romania and Southern Russia.
Romania
In Romania, a total of 187 plant samples were tested in 2008 (32 potato, 151 weed, and 3 maize plants). These samples had been collected from 2 potato fields (and their vicinities) in Fundulea (Southern Romania) and Csikszereda (Northern Romania). Stolbur was detected in 16.7% of the potato samples (all from Southern Romania) and in 1 sample of the weed Convolvulus arvensis.
In 2009, a total of 210 plant samples were tested (121 potato, 84 weed, 3 maize, 2 tomato plants). These samples had been collected from 2 potato fields located in Radovanu (Southern Romania). Stolbur was detected in 28.1% of the potato samples and in 22.6% of the weed samples (Convolvulus arvensis and Cuscuta sp.). In addition, stolbur was detected in 2 tomato plant samples.
Southern Russia
In Southern Russia, a total of 77 plant samples were tested in 2008 (33 potato, 29 weed, 7 eggplant, 5 pepper, 1 onion plants). These samples had been collected from 3 potato fields (and their vicinities) located in Gulkevichi (Krasnodar region), Azov and Mayad (Rostov region). Stolbur was detected in 22.1% of the potato samples and in all studied locations.
In 2009, a total of 100 plant samples were tested (54 potato, 35 weed, 2 carrot, 1 maize, 1 sugarbeet, 1 tomato plants). These samples had been collected from 4 fields located in Gulkevichi (Krasnodar region), Azov, Mayad and Niva (Rostov region). Stolbur was detected in 44.2% of the potato samples and in all studied locations. In addition, stolbur was detected in the tomato and beet samples, as well as in several pepper, eggplant and weed (C. arvensis, Cuscuta sp., Euphorbia falcata) samples.
Sources
Ember I, Acs Z, Munyaneza JE, Crosslin JM, Kolber M (2011) Survey and molecular detection of phytoplasmas associated with potato in Romania and Southern Russia. European Journal of Plant Pathology 130(3), 367-377.