Determination of the potential of some weeds to be used as an indicator plant in studies on Plum pox virus-T
 
 ABSTRACT 
 The plum pox virus (PPV) is the cause of sharka, the most destructive viral disease of Prunus species. A unique strain of PPV has so far been identified in Turkey and called as PPV-Turkey (PPV-T). Since viruses are obligate parasitic organisms, they cannot be cultured in artificial nutrient media. Weeds play a significant role in virus ecology and epidemiology as alternate hosts of plant viruses and as food plants for virus vectors. In this study, the potential of some weeds (such as Chenopodium album, Amaranthus retroflexus and Convolvulus arvensis) are indicators plants in experimental studies on PPV-T was investigated. C. album, A. retroflexus plants were inoculated by dusting three leaf on each 3-week-old plant. For each experiment, a homogeneous group of 10 plants grown singly in pots was inoculated PPV-T. Mock- and non-inoculated plants were used as negative controls. Inoculated plants were monitored dayl for symptom development. Following appearance of symptoms on PPV-T inoculated leaves tested by reverse transcription-polymerase chain reaction (RT-PCR). The results obtained from the indicator test showed that when mechanically inoculated of the two out of three plants tested species, C. album (6 out of 10 plants) and A. retroflexus (10 plants) reacted with infection. Initially, this indicator reacted with local symptoms, and later symptoms of systemic infection occurred.
 
 Keywords: Plum pox virus, PPV-Turkey, Herbaceous hosts, 
 Indicator plant