First report of Potato Wart Disease caused by Synchytrium endobioticum in Turkey

E. Çakır^1*

¹ Plant Protection Central Research Institute, Bağdat Caddesi No 250, P.K 49, Yenimahalle, 06172, Ankara, Turkey

Accepted for publication 29/03/05 

During October 2003,Potato (Solanum tuberosum) Wart Disease was detected for the first time on potato tubers in Aybastı county (Ordu province in Black Sea Region); a non-economically important potato growing district. In the same year, the disease was also found in Niğde and Nevşehir; two commercially-important potato growing provinces in central Anatolia. The potato varieties Agria, Donella, Granola, Marfona and Russet Burbank grown in Niğde and Nevşehir provinces were affected with the disease in very low percentages, not exceeding 1% of the total plants. In Ordu province, only a local variety, grown for home consumption, showed disease symptoms.

Figure 1: Warts of different sizes and colour on potato tubers (left) and a tuber completely covered in dark warts (right).

The disease exhibited typical symptoms on tubers that ranged from mild, small to severe, large warts that completely transform the tuber into a dark mass (Fig. 1A & B). Galls of various colours including shades of green, yellow but mostly brown appeared on the tubers by the end of the season. Summer and winter (resting) sporangia were observed from galls of different colours (Fig. 2A & B). Resting sporangia were typical for the fungus Synchytrium endobioticum; having irregularly shaped, dark brown walls. They were aseptate, light golden-brown in colour, thick walled, smooth, 40-50 mm diameter and spherical to ovoid in shape (Fig.2B) (Walker, 1983). Resting sporangia were isolated from the infected tubers and soil surrounding the infected plants using a method developed by Hampson & Thompson (1977).

Figure 2: Summer and winter (resting) sporangia of Synchytrium endobioticum (left) and resting sporangia (right).

Pathogenicity of the causal agent was proved by Glynne-Lemmarzalh method (Glynne, 1925; Lemmerzahl, 1930) by inoculating the potato sprouts at 1-2 mm long with some fresh wart tissue and incubating the plants at 18 ± 1ºC. Sporangia were reisolated from the warts observed 2 months later. Non-inoculated controls did not show any symptoms. The disease is now present on neighbouring potato fields covering 907.7 and 23.3 ha in Nevşehir and Niğde provinces respectively. It is present on land covering approximately 10 ha in Ordu province. This is the first report of Potato Wart in Turkey. The Ministry of Agriculture has been employing the EU (1969) Council Directive 69/464 of 8 December 1969 on control of Potato Wart Disease. Disease surveys for this pathogen are continuing in Turkey.

This work was supported by Turkish Ministry of Agriculture.

Glynne MD, 1925. Infection experiments with wart disease of potatoes, Synchytrium endobioticum (Schilb.) Per. Annals of Applied Biology 12, 34-60.

Hampson MC, Thompson PR, 1977. A quantitative method to examine large numbers of soil samples for Synchytrium endobioticum, the cause of potato wart disease. Plant and Soil 46, 659-664.

Lemmerzahl J, 1930. A new simplified infection procedure for testing potato cultivars for wart resistance. Zücher 2, 288-297.

Walker JC, 1983. Synchytrium endobioticum. CMI Descriptions of Pathogenic Fungi and Bacteria. No 755. Wallingford, UK: CAB International.

The British Society for Plant Pathology