Occurrence and primer inoculum sources of bacterial stem rot caused by Erwinia Species on tomato in the eastern Mediterranean region of Turkey


Aysan Y., Sahin F., Cetinkaya-Yildiz R., Mirik M., Yucel Y.

ZEITSCHRIFT FUR PFLANZENKRANKHEITEN UND PFLANZENSCHUTZ-JOURNAL OF PLANT DISEASES AND PROTECTION, cilt.112, sa.1, ss.42-51, 2005 (SCI-Expanded) identifier identifier

Özet

Bacterial stem rot caused by Erwinia carotovora subsp. carotovora (Ecc) and E chrysanthemi (Ech) was observed in the eastern Mediterranean region of Turkey. The pathogens cause wilting of the whole plant, water-soaking areas on the stem, hollowing of the pith, browning of the vascular tissue and maceration in stem and fruits in plastic-covered greenhouses. Based on external disease symptoms, the prevalence of the disease ranged from 13 and 24 % in 1999 and 2000, respectively. Incidences of the disease were 12 and 20 % in 1999 and 2000 in the commercial greenhouses surveyed in the eastern Mediterranean region of Turkey. This is the first report of Erwinia species causing stem rot on tomato in Turkey. Primary inoculum sources of the disease were investigated with rifampicin-resistant strains in/on plant debris and seeds. Soft rot Erwinias were recovered from plant debris in summer period in the region for 2 years. The pathogenic bacteria were able to survive on the dried seeds for at least 7 months, but not more than I I months. Tomato seedlings from naturally contaminated seeds grown in sterile soil under mist had leaf lesions, irregular, black-brown spots, no halo. This is the first study showing that both soft rot Erwinias were able to survive in/on the diseased tomato plant debris and tomato seeds, which may be potential primary inoculum of the disease. A polyclonal antiserum (ME-OZ) has been developed in the present study, and successfully used in indirect ELISA for rapid diagnosis of stem rot disease on tomato. Furthermore, our data confirmed FAME analysis is a rapid and reliable method for identification and differentiation of Ecc and Ech strains isolated from soft rot samples of tomato.