Evaluation of the Susceptibility of some Tomato Hybrids used in Greenhouses of Syrian Coast Against Bacterial Stem Pith Necrosis Disease
Abdullatif Al Ghazzawi*(1) Mahmoud Abu Ghoura(2) Nabeel Al Ahmad Bek(1) and Raghda Al Baghdadi(1)
Received: 13/12/2015 Accepted: 28/04/2016
Tomato stem pith necrosis disease which is caused by Pseudomonas corrugata Roberts & Scarlettis is one of the most important diseases infecting tomatoes which grown in the greenhouses that spreaded in the Syrian coast region. 40 isolates of P. corrugata were collected from Tartous and Latakia governorates, and their ability of infection, and virulence were evaluated. The most three virulent isolates (G12.1, G14.3 and G35) were chosen to test their infection ability on ten tomato hybrids which most grown in the greenhouses, depending on their susceptibility scale from 0 to 3. The tested isolates were varied in their virulence in Tartous and Latakia, and within the same governorate. Some isolates from Tartous (G35, G14.3 and G12.1) were superior in their ability of infection compared with the rest of isolates collected from both governorates against the plants of the hybrid Code 80 F1, the values of infection were 4.9, 4.7 and 4.4, respectively. Meanwhile, both Tartous isolate 107.1 and Latakia isolate 121.1 were in the last order in their ability of infection. The results showed also that all ten tested tomato hybrids were infected by the bacteria under the artificial inoculation conditions with variable degrees. The hybrid Saida was the highest susceptible with an average of infection 6.61 and the lowest was hybrid Sidra with an average of infection 2.31. The tested hybrids were divided according to the infection scale to high infected, moderate infected, and partially tolerant and tolerant.
Key words: Pith necrosis, Pseudomonas corrugata, Syria, Tomato hybrids.