Bacterial soft rot of tomato in plastic greenhouses in Crete

Abstract

SUMMARY During recent years a new disease has been noticed on tomatoes grown in Polythene greenhouses in Crete. Early symptoms are yellowing of the lower leaves, and a yellow brown discoloration of the pith and stem xylem. As leaves wilt and die there is progressive yellowing towards the top of the plants. A progressive disintegration of the cortical tissues follows which results in a soft rot and a longitudinal splitting of the stem running mainly upwards. Soft rot of the fruits rarely appears. Severely infected plants may wilt and die, but other less affected plants often survive and yield normally. Very vigorous plants grown under humid conditions are more susceptible. Often more than 20% of the plants are infected. Isolations were made from stem (xylem, cortex and pith), from leaf xylem and from fruits of infected tomato plants collected throughout the island from 1979 to 1985. Bacteria of the genus Erwinia and Pseudomonas were consistently isolated. On the basis of physiological and biochemical characters of 49 representative pathogenic isolates, 22 were identified as Erwinia carotovora subsp. carotovora, 10 as Erwinia carotovora subsp. atroseptica, four as Pseudomonas viridiflava and 13 as Pseudomonas fluorescens biotype I. All disease symptoms were reproduced when artificial inoculations were made with the above isolates in the laboratory (20°C and 100% r.h.) on 3–4 week tomato plants and in a commercial greenhouse on 4–5 months tomato plants. Bacteria used for inoculations were reisolated. Results indicated that the disease symptoms as described may be caused by four different bacteria species.

Pseudomonas corrugata and Pseudomonas marginalis associated with the collapse of tomato plants in rockwool slab hydroponic culture

“…carotovora (Dhanvantari & Dirks 1987), P. fluorescens biotype A, P. viridiflava and e. c. subsp. atroseptica (Malathrakis & Goumas 1987), fluorescent Pseudomonas sp. (Dhanvantari 1990), P. mediterranea (Catara et al 2002), erwinia chrysanthemi (Asyan et al 2003) and ralstonia solanacearum, biovar 2, race 3 (Loreti et al 2007).…”

Diversity among Pseudomonas corrugata and Pseudomonas mediterranea isolated from tomato and pepper showing symptoms of pith necrosis in Greece

“…Greenhouse‐cultivated tomato and pepper are two of the most important crops for the Cretan economy, with losses ranging from 2 to 10% of cultivated plants in plastic covered greenhouses during winter, although under certain conditions this can rise to over 20% (Malathrakis & Goumas, ). Because pith necrosis of Solanaceae is a serious threat for the Cretan commercial fields, previous work has tried to elucidate the underlying intra‐ and interspecific genetic variability of P. viridiflava (Sarris et al ., ) and P. cichorii (Trantas et al ., ) pathogens.…”

Epiphytic survival of Pseudomonas viridiflava on tomato and selected weed species

“…Pseudomonas viridiflava (Burkholder) Dowson (hereafter PV) has been associated with foliar, bud, flower, fruit, stem, or root diseases on a variety of plant species including tomato [5,7,11,15,16,21,24,25,26,34,35,36,39,40]. In early Offprint requests to: R.L.R.…”